HT 12 Unimog 1.96 1

1 Introduction

1.1 General You decided to buy a Schaeff backhoe excavator HT 12. The confidence placed in this model will be rewarded by the efficient and economical performance of the machine. These operating instructions contain all information necessary for the correct use of the machine. Please read them carefully before putting the machine into operation and make sure that they are kept at hand at all times. Should you need further explanations or should anything be unclear, please contact your dealer immediately. Special equipment and attachments are not included in these operating instructions. We reserve the right to make improvements on the machine within the scope of impending technical developments, without incurring any obligation to change these operating instructions.

Note Any modifications of Schaeff products and their equipment using extras and work attachments which are not included in our product range require our written approval. If our approval is not sought, our warranty expires, as does our product liability for any resulting consequential damages.

Note The vehicle identity number of the backhoe excavator is stamped on the identification plate located on the slide.

Please state the machine type and the machine identity number when making inquiries or orders, and in all written correspondence. Our address : Head Office / Sales Service Spare Parts Karl Schaeff GmbH & Co. Karl Schaeff GmbH & Co. Schaeff Ersatzteile-Service Maschinenfabrik Maschinenfabrik GmbH & Co.KG Postfach 61 • D-74595 Langenburg Postfach 1264 • D-91534 Rothenburg Postfach 12 64 • D-91534 Rothenburg Schaeffstr.8 • D-74595 Langenburg Erlbacher Str. 113 • D-91541 Rothenburg Erlbacher Straße 113 • 91541 Rothenburg Tel. +49 7905 58-0 Tel. +49 9861 972-451 Tel. +49 9861 972-0 Fax +49 7905 58-114 Fax +49 9861 972-460 Fax +49 9861 972-410

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1.2 Proper use The backhoe excavator with standard bucket, grab or loading bucket equipment is intended solely for work which is suitable for the function of the machine and its work implements. Such work involves loosening, taking up, transporting and dumping rock or other materials as well as loading these materials on conveyor belts or other means of transport. Any usage above and beyond that specified here and any non-compliance with the manufacturer’s instructions is regarded as improper use. The manufacturer shall not be liable for damages resulting from improper use. This risk is borne solely by the plant operator. Compliance with the operating and maintenance instructions, the performance of maintenance work as specified and adherence to replacement intervals all form part of the concept of proper use.

1.3 Warranty and Maintenance

Safe working conditions and good working order of the machine are prerequisites for efficient work. Your Schaeff backhoe excavator fulfils these requirements when correctly handled and when serviced and maintained as specified. Careful observation of the machine whilst in function and the use of the specified lubricants will prevent malfunction. Trained specialist personnel are responsible for any servicing of the machine which requires expert knowledge. Inspections and repairs must therefore be carried out by your dealer’s customer service. In respect of possible claims for damages during the warranty period, all customer service work specified in the maintenance and inspection plan must be carried out at the specified intervals. After the warranty period, too, regular maintenance must be performed in order to ensure that the machine is constantly in good working order and enjoys a reasonable service life. Insist that only original SCHAEFF spare parts are used in the event of any repair work. In this way, you will have a product of lasting high quality, thereby ensuring that your machine maintains its original condition.

HT 12 Unimog 1.96 3

1.4 Delivery and handing-over instructions The following checklist is to be adhered to when handing over the machine. Operating instructions The operating instructions should be read side by side, and be explained in detail through practical training on the machine. • Regulations for preventing accidents

published by the employer’s liability insurance associations in the user’s country

• Technical data • Operational elements, control and

warning indicators • Checks before putting the machine

into operation • Actuation of all functions • Explanation of maintenance and

inspection intervals according to Maintenance and Inspection Plan by demonstrating maintenance points on machine

• Lubrication intervals and points of lubrication according to lubrication chart and demonstration of these points on the machine

Spare parts list • Structure of spare parts list, figures

and the respective descriptions • Instructions for ordering spare parts:

always state the type of machine, the vehicle identity number (Fz-Id.Nr.), parts designation, complete spare part number, piece number, delivery address, etc.

Warranty • Explanation of warranty covered by

manufacturer • Explanation of inspection cards and

note on maintenance and inspection plan

• Correct filling out of warranty/handing-over card and returning the latter to Schaeff

1.5 Notes on using the instruction book

References to pictures and items The references to pictures and items contained in the text, such as “Figure 2/4“ or (2/4) mean figure 2, item 4 (Bild = Figure). The figures shown in this list partly contain additional equipment.

Attention This danger symbol is used when inexact compliance or non-compliance with operating instructions, specified work procedures, etc. may lead to injury or fatal accidents.

Note This symbol is employed when inexact compliance or non-compliance with operating instructions, specified work procedures, etc. may lead to damage to the machine. This symbol is also used for information which is of particular importance to the user of the machine.

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2 Accident prevention 2.1 Before putting the earth-moving machine into operation, read these operating instructions carefully and strictly observe the indicated references.

Note Some of the following points are based on the laws and regulations valid for the Federal Republic of Germany. This is the case for the regulations for the prevention of accidents mentioned in paragraph 2.2, which only apply to Germany. For all other countries, local regulations apply.

2.2 National safety regulations, e.g. the Accident Prevention Regulations (UVV) published by the employer’s liability insurance associations in the user’s country must be strictly observed. One copy of the Accident Prevention Regulations applicable for excavators, loaders, etc. (Earth-moving machines VBG 40), published by the “Tiefbau-Berufsgenossenschaft“, is supplied with the machine or can be obtained from this organisation. We recommend reading these regulations carefully. The site operator and the driver of the machine are responsible for compliance with safety regulations. 2.3 If necessary, but at least once a year, earth-moving machines must be submitted to a general inspection according to the existing UVV regulations (Accident Prevention Regulations). This inspection has to be carried out by an expert (e.g. machine engineer or machine foreman). The results of this inspection must be recorded in writing and this record must be kept until the next inspection takes place.

2.4 The operation of earth-moving machines may only be assigned to suitable and reliable persons of the minimum legal age, and the site operator or his deputy must make sure in advance that these persons are familiar with the operation of the machine. 2.5 In case defects cannot be remedied immediately, the driver of earth-moving machines has to report any shortcomings immediately to the supervisor and his replacement, if there is a change of operator. Defects which may lead to dangers must be remedied immediately. 2.6 Daily before commencing work and after every change of work attachments, the correct fastening of the work attachments must be verified. Work attachments are to be carefully moved at low height. 2.7 Prior to and during work, the drivers of earth-moving machines must ensure that nobody who may be jeopardised is in proximity of the machine. If necessary, warning signals are to be given. 2.8 Whenever they are stopped, earth-moving machines must be reliably secured to avoid any unintentional movement. 2.9 It is the driver’s responsibility to ensure that the operator’s stand and other parts of the machine which have to be stepped on are free of dirt, grease, oil, ice and snow.

HT 12 Unimog 1.96 5

2.10 Only carry out maintenance and repair work on the excavator when the work equipment is lowered to the ground, the engine is switched off, and the hydraulic system is relieved of pressure. With the engine off, lower the work equipment to the ground and actuate all hydraulic control levers until there is no pressure in the hydraulic system.

Attention When working under the raised work equipment, it is essential to secure the latter by appropriate means.

2.11 Never attempt to lift the machine yourself or leave it in that position for repairs. Place pieces of wood between the jack and the machine when jacking up the machine. Be aware that shifts in weight may occur.

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3 Technical data 3.1 Working diagram

Fig. 4

HT 12 Unimog 1.96 7

3.2 Dimensions and weights without mounting group

Dipperstick 1,500 mm 1,800 mmOperating weight in kg without work attachments

approx. 1250 approx. 1300

Digging depth in mm 3,600 3,900 Dumping height in mm 3,200 3,200 Max. reach in mm“ 5,050 5,350 Bucket turning angle in ° 195 195 Boom slewing area in ° 185 185 Lateral parallel adjustment in mm 1,260 1,260 Total width in mm 2,000 2,000 Payload at max. reach in N 8,600 7,500 * Ripping force in N 25,000 22,000 * Breakout force in N 28,550 28,550 * Values are theoretical according to DIN 24086 Dimensions apply for standard bucket 280 - 800 mm.

3.3 Hydraulic system - Technical data

Power required for

hydraulic system 20 - 28 kW

Working pressure 175 bar

Capacity 70 - 80 l/min

Tank filling quantity approx. 54 l

Hydraulic oil temperature max. 90°C ( ΔT 60°C )

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3.4 Lubricant specifications Hydraulic system: Mineral hydraulic oils

The limit values for hydraulic oils which can be used for Schaeff construction machines and attachments are approx. 12 mm ²/s (cSt) at 100°C and approx. 1500mm ²/s (cSt) at -10°C. See also hydraulic oil recommendation chart for Schaeff construction machines and attachments.

Biodegradable hydraulic oils As an alternative to mineral oils, we recommend bio- degradable hydraulic oils of a synthetic ester base. The same viscosity specifications apply as for mineral oils.

Note When changing from mineral to biodegradable hydraulic oils, the tank and hydraulic system must be completely drained, cleaned and flushed.

For further details before changing oils, please consult your Schaeff dealer. Grease nipples: Multi-purpose grease to DIN 51825-K 2 G-40

Note The safety data sheets of the mineral oil companies must be observed when dealing with lubricants.

3.5 Work attachments

Width Capacity Bucket with ejector 290 mm 0.062 m3 Bucket with ejector 350 mm 0.072 m3 Bucket with ejector 450 mm 0.100 m3 Bucket 600 mm 0.164 m3 Bucket 800 mm 0.204 m3 Ditch-cleaning bucket 1,250 mm 0.115 m3 Ditch-cleaning bucket 1,500 mm 0.160 m3 Clamshell grab 350-450 mm

- Further work attachments available on request -

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3.6 Other equipment • Load hook in connection with overload warning device • Ripper tooth • Overhead guard • Cab • Widened support - Further optional equipment available on request -

Note Any modifications of Schaeff products and their equipment using extras and work attachments which are not included in our product range require our written approval. If our approval is not sought, our warranty expires, as does our product liability for any resulting consequential damages.

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4 Mounting and dismounting instructions

4.1 Mounting

Note The host vehicle must be equipped with the appropriate mounting group.

• The host vehicle must be driven backwards to the backhoe excavator. • Establish hydraulic connection for excavator by connecting the hydraulic hoses to the quick couplings. • Connect the connection hoses of the tilt cylinder with the Unimog-connecting boxes. • Switch on power take-off. • Adjust the excavator with stabilisers and dipperstick to level. • Drive host vehicle backwards and hook the backhoe excavator in slide (6/1). • Fasten and secure the excavator using retaining blocks (6/2) and pins (6/3). • Attach the arm (6/4) in the middle of the vehicle on the „center of the underslung frame“ (6/5). • Bring the excavator to working position and check functions. • The backhoe excavator is now ready for operation.

4.2 Dismounting • Move the slide to the middle of the mounting plate. • Place the working equipment to the ground. • Lift the backhoe excavator by actuating the stabilisers to such a degree that the Unimog is no longer burdened by the excavator. • Loosen the excavator fastening (retaining blocks and arm ). • Move the host vehicle forward so that the backhoe excavator stands free. • Retract the stabilisers, turn off the power take-off and stop the engine. • Loosen the hydraulic connection for the excavator and the tilt cylinders. Connect the air hose to the return line hose on the host vehicle. • Protect the connection hoses of the backhoe excavator from contaminations.

fig. 6

HT 12 Unimog 1.96 11

5 Operation 5.1 Operator controls

Fig. 7 1 Operator control for excavator equipment 2 Operator control for excavator equipment 3 Operator control for stabiliser, right 4 Operator control for stabiliser, left 5 Slide lock 6 Overload warning device

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5.2 Making the backhoe excavator ready for operation • Start the Unimog according to the Unimog -

operating instructions and let the engine run at idle speed.

• Lower the excavator from transport to working position according to chapter 6.

• Switch on the power take-off (8/1) in the operator’s cab of the Unimog.

• Increase the engine speed through external hand adjusting lever to nominal speed of 1,550 rpm (approx. ½ gas).

Note Only switch on power take-off during excavator operation.

• Stabilising the backhoe excavator • Release the parking brake of the Unimog. • Apply the steering lock.

Note When working with the backhoe excavator slewed sideways we recommend employing an additional support in order to improve the stability of the Unimog with the HT 12 attached. When the excavator is slewed sideways, the additional support (9/1) on the supporting foot, to which the excavator is slewed, must be employed. When driving on public roads, the additional support must be dismounted.

HT 12 Unimog 1.96 13

5.3 Excavator operation 5.3.1 General

The excavator is equipped as standard with ISO control, upon which the following description is based.

Attention If the customer so wishes, the excavator may be equipped with a different control. Your excavator must therefore be checked to see whether or not a different control is installed. Incorrect operation may endanger persons or objects.

Before commencing work, memorise the lever controls well. Commence at low engine speed when familiarising yourself with the controls.

5.3.2 Actuation of work equipment

5.3.3 Actuation of stabilisers

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5.4 Lateral adjustment of the work equipment

5.4.1 General The work equipment can be slewed sideways on the mounting plate. This allows accurate and safe work close to walls, e.g. house walls. Furthermore, the reach of the excavator can be increased when working across the direction of travel.

Note Apply the widened support if necessary.

5.4.2 Loosening and positioning the slide To do so, the excavator is slewed in the direction of or against the direction of slewing to the end position and the ball valve (7/5) is opened. After the bucket has been lowered to the ground and the dipperstick actuated, the slide with boom is drawn or pushed to the desired position.

5.4.3 Clamping the slide

After positioning the slide, the ball valve must be closed and the actuating lever for „Boom up“ for pressure build-up in the clamping cylinders must be actuated. Thus the slide is clamped and the excavator is ready for operation.

Attention It is important that the machine is positioned in exact accordance with these guidelines. Take care to ensure that the slide is clamped in the proper manner. Danger of accident

Note When working, the ball valve must always be closed and may only be opened for lateral adjustment.

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5.5 Crane operations

5.5.1 General Crane operations are the hoisting, transporting and lowering of loads with the aid of a fixing device (rope, chain, etc.), whereby the assistance of personnel is required to attach and release the load.

5.5.2 Safety devices

The excavator may only be used for crane operations when the prescribed safety devices are present: - Secure attachment of loading implements - Table of carrying capacity, see section 5.5.5 - Overload warning device and a hose-rupture safety valve if the permissible carrying capacity exceeds 1,000kg. The load limit is marked on the overload warning device (7/6) Danger starting from: 90 bar

5.5.3 Attachment of loads

Note Loads must be attached in such a way that they cannot slip or fall out.

Possible forms of attachment • Load hook attached instead of a bucket, etc. • Hook with safety net welded onto the bucket rod (not possible in the case of quick-mounting buckets with ejectors). A suitable, appropriately sized loading implement must be employed for picking up the material to be lifted. Always wear protective gloves when working with loading implements.

5.5.4 Attachment and carrying of loads

Attention Personnel guiding the machine and attaching loads must remain only in the machine operator’s field of vision.

Personnel attaching loads may only approach the boom from the side and with the machine operator’s permission. The machine operator may only give his permission if the machine is standing still and the work equipment is not in motion. The machine operator must carry loads as close to the ground as possible and prevent them from swinging. Machines may only travel with an attached load if the path of travel is fairly even.

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5.5.5 Carrying capacities with the following equipment: Without bucket, with load hook Bucket cylinder, rocker arm and bucket rod left on the machine Machine supported

Values without brackets : All values apply for the complete slewing range and include a stability factor of 1.25. These values are determined according to DIN 15019 page 2 and presented according to DIN 24083. Values in brackets : Values correspond to the hydraulic lifting force and only apply in the longitudinal direction (vehicle longitudinal axis) with the undercarriage supported.

HT 12 Unimog 1.96 17

5.6 Changing work attachments 5.6.1 General

In order to achieve maximum utilisation of the machine for a variety of applications, a great number of work attachments are available.

Attention When the work attachments have been removed, they must be secured against tilting and overturning to avoid possible injuries to persons.

Note The hydraulic system must be relieved of pressure before hydraulic connections are disconnected.

5.6.2 Assembly of work attachments

Note The bearings of the work attachment, the dipperstick and the bucket rod must be free of dirt.

• Procedure for changing attachments Lower the work attachment to the ground and position so that it cannot tilt. Remove the pins which connect the attachment to the dipperstick and the bucket rod. Mount another work attachment.

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6 Transport position when driving on public roads 6.1 Backhoe tilting for transport Description to be seen in the direction of the backhoe !! • Move the boom completely to the right and clamp. Fully retract the boom, close the bucket and

retract the dipperstick • Slew the boom to the inside, secure the dipperstick with a turnbuckle on the mounting plate • Apply the parking brake, release the steering lock • Retract the stabilizers • Fold up the driver’s seat and secure • Position both lock pins (10/1) between the mounting frame and the mounting device in

position „unlocked“ • Ensure that the bolt (10/2) for transport lock (on the right - in backhoe direction) is in posi-tion

„unlocked“ • Tip the backhoe onto the platform by actuating the tilt cylinder via the valve lever in the Uni-

mog driver’s cab

Attention People must not remain on the platform. Danger of injury !

• Position the bolt (10/2) between the mounting frame and the mounting device in position „locked“ for transport lock.

Note Some Unimog types are equipped with lock valves for the tilt cylinder. The lock valves are either to be opened or closed, depending upon the operation.

• Turn off the accessory drive • Check the vehicle according to the guidelines valid in the user’s country, e.g. Regulations

Authorising the Use of Vehicles for Road Traffic (StVZO) in Germany • Attach the protection cover for the stabilizer plates

6.2 Changing the backhoe from transport position to working position The re-positioning is done in reverse order compared to tilting the backhoe for transport:

Attention The valve for the tilt cylinder (valve lever in the driver’s cab of the Unimog) has to be in neu-tral position. Ensure that the valve lever is not in floating position

• Remove the protection cover for the stabilizer plates • Turn on the accessory drive

Note Some Unimog types are equipped with lock valves for the tilt cylinder. The lock valves are either to be opened or closed, depending upon the operation

• Position the pin (10/2) between the mounting frame and mounting device in position „unlocked“ • Ensure that both pins (10/1) for the backhoe lock are in position „unlocked“ • Tilt the backhoe to its working position by actuating the tilt cylinder via the valve lever in the

driver’s cab of the Unimog

Attention People must leave the tilting and slewing area. Danger of injury !

• Position both lock pins (10/1) between the mounting frame and mounting device in posi-tion „locked“

• Fold down the driver’s seat and secure • Extend the stabilizers • Release the parking brake, apply the steering lock • Bring the boom to its working position

HT 12 Unimog 1.96 19

fig. 10

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7 Care and maintenance

7.1 General notes The good operating condition and life expectancy of machines are largely influenced by care and maintenance. For this reason, it is in every machine owner’s interest to perform the specified maintenance work and comply with the service intervals. This section deals in detail with periodic maintenance, inspection and lubricating tasks. Furthermore, during the warranty period three thorough inspections are stipulated, which must be carried out by trained specialist personnel. Type-specific maintenance and inspection plans for this purpose are contained in every instruction book and every warranty certificate.

Note Service and wearing parts for inspections should be ordered well in advance!

Inspection intervals 1st inspection - after approx. 100 operating hours 2nd inspection - after approx. 500 operating hours 3rd inspection - after approx.1,000 operating hours subsequently, every 500 operating hours

Note The three inspections are obligatory and must be paid for. If they are omitted, the warranty may be subject to restrictions.

It is essential that the recommendations in chapter 2, “Accident Prevention”, are observed.

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7.2 Inspection parts and aids Service parts Spare part number Hydraulic oil filter cartridge 5 559 652 510 Ventilation filter 5 003 605 350 Extras Schaeff hydraulic oil, mineral 4 312 005 050 Schaeff hydraulic oil, biodegradable For further information, please contact your Schaeff dealer

Note Service parts for inspections should be ordered well in advance!

Lubricants The machine’s life expectancy and operating condition are largely dependent upon the use of the specified lubricants and compliance with the service intervals. If lubricants which do not conform to our recommendations are used, consequential damages may occur for which we will not assume liability, even inside the warranty period. For lubricant specifications see section 3.4.

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7.3 Care and cleaning

Note The machine must be cleaned on a suitable surface with an oil separator.

1. Neither a steam-jet appliance nor a high-pressure cleaning apparatus may be used for cleaning during the first two months after the machine is used for the first time or when newly painted. 2. Do not use aggressive detergents for cleaning the machine. We recommend using commercially available cleaning agents for passenger cars. 3. When cleaning with a steam-jet appliance, the hot water jet must not exceed 80 °C and a spray pressure of 20 bar. The nozzle must be at a minimum distance of 30 cm from the machine. 4. Do not clean the operator’s seat with direct water, steam or high pressure jets. 5. After each wet clean, the machine must be lubricated in accordance with the lubricating plan and a test of all work cycles, support and driving functions carried out.

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7.4 Daily and weekly tasks Inspection and maintenance jobs to be performed by service personnel Daily • Visual inspection (general) e.g. for material cracks, external damages, completeness, etc. • Check for leaks in:

pipes, hoses, control valve, hydraulic pumps, cylinders, etc.

Note When tightening hoses or pipe connections, lock screw-in couplings to prevent rotation

• Check smooth running of operator controls • Check electrical equipment • Grease machine according to overview of lubricating points

Weekly • Take care to ensure that the support for the mounting device is securely fastened on the host

vehicle • Check the condition of the fastening parts for the mounting device and ensure that they are

tightly fastened. • Check that the connection lines and hydraulic couplings function perfectly

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7.5 Overview of lubricating points

Grease all lubricating points with multi-purpose grease T h e i n t e r v a l s s t a t e d a p p l y t o o n e - s h i f t o p e r a t i o n

No.

Lubricating point Qty.

Daily

1 Bucket - Dipperstick 1 X 2 Bucket - Bucket rod 1 X 3 Bucket cylinder - Bucket rod - Rocker arm 1 X 4 Dipperstick - Rocker arm 1 X 5 Bucket cylinder - Dipperstick 1 X 6 Boom - Dipperstick 1 X 7 Dipperstick cylinder - Dipperstick 1 X 8 Dipperstick cylinder - Boom 1 X 9 Boom cylinder - Boom 1 X

10 Boom cylinder - Slewing column 1 X 11 Boom - Slewing column 1 X 12 Slewing column - Slide 2 X 13 Slewing cylinder - Slide 4 X 14 Slewing cylinder - Slewing column 2 X 15 Operator controls 2 X

Note • In the event of special operating conditions, e.g. working on

sandy ground, the lubrication intervals should be shortened, in order to encourage self-cleaning of bearing points.

• Replace damaged grease nipples immediately and check if grease passes through.

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7.6 Inspection plan

To be carried out by trained specialist dealer personnel. O = Checking, maintenance X = Replacement

Operating hours

min 2x

min 1x

Perform work with machine at operating temperature 100

500

1000

1500

2000

2500

3000

year-ly

year-ly

1 Check whether machine-specific instruction book is in the machine

O O O O O O O

2 Check suspension of backhoe excavator. O O O O O O O

3 Check bearing bushes and bolts of work equipment and replace if necessary

O O O O O O O

4 Check smooth running of operator controls and adjust if necessary

O O O O O O O

5 Check or change hydraulic oil O O X O X O X X

6 Replace hydraulic oil filter cartridge X X X X X X X X

7 Replace ventilation filter X X X X

8 Check speed of hydraulic pump O O O O O O O

9 Check tightness of all pipes, hoses, control valve, hydraulic pumps, cylinders, etc.

Note When tightening hose and pipe connections, screw-in couplings must be locked to prevent rotation

O O O O O O O

10 Check function of electrical equipment O O O O O O O

11 Grease machine according to overview of lubricating points O O O O O O O

12 Check function, condition and completeness of safety equipment O O O O O O O

13 Hydraulic function check with pressure function test O O O O O O O14 Test run and test work O O O O O O O

15 Initial inspection cards and return to Schaeff O O O

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7.7 Hydraulic oil For hydraulic oil specifications, see section 3.4. Change according to inspection plan, section 7.6. Hydraulic oil change

Note Change the hydraulic oil at operating temperature.

• Retract all hydraulic cylinders. • Stop the engine • Remove the cap of the ventilation filter (15/1) • Slacken the drain plug (15/2) on the hydraulic oil tank and drain oil into clean receptacles.

Note Collect the waste oil, do not allow it to seep into the ground. Dispose of according to regulations !

• Flush and clean the hydraulic tank as required • Carefully close the drain plug. • Fill with clean hydraulic oil via the filler and ventilation filter until the correct level on the sight glass (15/3) is reached. • Screw on the ventilation filter cap. • Check the tightness of the tank.

fig.15

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7.8 Hydraulic oil return filter Change according to inspection plan, section 7.6

Note After a larger repair job, following the test run the filter cartridge must be renewed as well.

Changing the filter cartridge:

Note Service and wearing parts for inspections should be ordered well in advance!

• Stop the engine. • Loosen the ventilation filter cap (15/1) on the

hydraulic oil tank. • Close the shut-off valves in the suction and

return lines on the hydraulic oil tank. • Clean the outside of the return filter. • Unscrew the filter cartridge (16/1) using a

strap wrench.

Note Dispose of the filter cartridge according to regulations !

• Apply a light coat of oil to the seal ring and tighten according to printed-on instructions.

• Screw on the ventilation filter cap. • Open shut-off valves. • Check the tightness of the return filter.

7.9 Ventilation filter of hydraulic oil tank Change according to inspection plan, section 7.6 Remove the ventilation filter (15/4) and replace it by a new one.

Note Replace the filter, too, if the cap is dirty, e.g. due to oil mist.

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8 Operating problems 8.1 General Operating problems are often the result of incorrect handling of the machine, the use of unsuitable materials or irregular maintenance. The following table presents a summary of a range of problems and their probable causes. If a problem can only be eliminated through repair, then the responsible Service Agent must be called in.

8.2 Host vehicle All defects and faults in the host vehicle must be examined as described in the separate instruction book for the host vehicle. During the warranty period, malfunctions must be dealt with by the responsible SERVICE Agent. Fault Possible cause Remedy 8.3 Excavator equipment is not working

1 Unimog power take-off for hydraulic pump is not working

Determine cause

2 Oil supply to excavator interrupted Check connection 3 Oil supply to hydraulic pump

interrupted Check lines

4 Main high-pressure relief valve has failed

Check main high-pressure relief valve and replace, if necessary

5 Hydraulic pump has failed Have hydraulic pump checked by a specialist and replace completely, if necessary

8.4 Unit is working too slowly and system is becoming too hot 1 Main high-pressure relief valve set

too low or faulty Adjust main high-pressure relief valves, replace, if necessary

2 Impermissible degree of wear of hydraulic pump

Replace hydraulic pump

3 Incorrect hydraulic oil Quality of hydraulic oil must conform to our recommendation

4 Air in hydraulic system Tighten connections with engine off and system relieved of pressure

8.5 Hydraulic cylinders are not functioning satisfactorily1 Sleeve sets in hydraulic cylinders

worn Renew sleeve sets

2 Secondary valves faulty Check secondary valves and replace if necessary

3 Impermissible degree of leakage of the control valve

Check control valve, seal and replace if necessary

8.6 Trouble in the electrical system 1 Lighting does not come on Check cables, connections, etc.

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Table of contents

1 Introduction ................................................................................................................ 1 1.1 General ............................................................................................................................... 1 1.2 Proper use ......................................................................................................................... 2 1.3 Warranty and Maintenance ................................................................................................ 2 1.4 Delivery and handing-over instructions ............................................................................... 3 1.5 Notes on using the instruction book ................................................................................... 3

2 Accident prevention ................................................................................................... 4 3 Technical data ............................................................................................................ 6

3.1 Working diagram................................................................................................................. 6 3.2 Dimensions and weights without mounting group .............................................................. 7 3.3 Hydraulic system - Technical data ...................................................................................... 7 3.4 Lubricant specifications ...................................................................................................... 8 3.5 Work attachments ............................................................................................................... 8 3.6 Other equipment ................................................................................................................. 9

4 Mounting and dismounting instructions ................................................................ 10 4.1 Mounting ........................................................................................................................... 10 4.2 Dismounting ..................................................................................................................... 10

5 Operation .................................................................................................................. 11 5.1 Operator controls .............................................................................................................. 11 5.2 Making the backhoe excavator ready for operation .......................................................... 12 5.3 Excavator operation .......................................................................................................... 13

5.3.1 General ..................................................................................................................... 13 5.3.2 Actuation of work equipment ..................................................................................... 13 5.3.3 Actuation of stabilisers .............................................................................................. 13

5.4 Lateral adjustment of the work equipment ........................................................................ 14 5.4.1 General ..................................................................................................................... 14 5.4.2 Loosening and positioning the slide .......................................................................... 14 5.4.3 Clamping the slide .................................................................................................... 14

5.5 Crane operations .............................................................................................................. 15 5.5.1 General ..................................................................................................................... 15 5.5.2 Safety devices ........................................................................................................... 15 5.5.3 Attachment of loads .................................................................................................. 15 5.5.4 Attachment and carrying of loads ............................................................................. 15 5.5.5 Carrying capacities ................................................................................................... 16

5.6 Changing work attachments ............................................................................................. 17 5.6.1 General ..................................................................................................................... 17 5.6.2 Assembly of work attachments ................................................................................ 17

6 Transport position when driving on public roads ................................................. 18 6.1 Backhoe tilting for transport .............................................................................................. 18 6.2 Changing the backhoe from transport position to working position .................................. 18

7 Care and maintenance ............................................................................................. 20 7.1 General notes ................................................................................................................... 20 7.2 Inspection parts and aids .................................................................................................. 21 7.3 Care and cleaning ............................................................................................................ 22 7.4 Daily and weekly tasks ..................................................................................................... 23 7.5 Overview of lubricating points ........................................................................................... 24 7.6 Inspection plan ................................................................................................................ 25 7.7 Hydraulic oil ...................................................................................................................... 26 7.8 Hydraulic oil return filter .................................................................................................... 27 7.9 Ventilation filter of hydraulic oil tank ................................................................................. 27

30 HT 12 Unimog 1.96

8 Operating problems ................................................................................................. 28 8.1 General ............................................................................................................................. 28 8.2 Host vehicle ...................................................................................................................... 28 8.3 Excavator equipment is not working ................................................................................. 28 8.4 Unit is working too slowly and system is becoming too hot .............................................. 28 8.5 Hydraulic cylinders are not functioning satisfactorily ........................................................ 28 8.6 Trouble in the electrical system ........................................................................................ 28

Anbaubagger HT12 Unimog 10.97