975, 975XL975, 975XL¾”-2”¾”-2”

Modification OverviewModification Overview Production of the original 975 began in 1990. Production of the original 975 began in 1990.

This version had buna-n check discs and did not This version had buna-n check discs and did not have replaceable check seats. Discontinued in have replaceable check seats. Discontinued in 1992.1992.

The 975A had bronze replaceable seats.The 975A had bronze replaceable seats.

The 975XL (1993-Current) has plastic The 975XL (1993-Current) has plastic replaceable seats and silicone check discs.replaceable seats and silicone check discs.

A lead free version 975XL2 was introduced in A lead free version 975XL2 was introduced in 2010.2010.

Check Cover RemovalCheck Cover Removal

Cover is threaded into Cover is threaded into body and o-ring body and o-ring sealed.sealed.

Cover is spring Cover is spring loaded.loaded.

Loosen cover with Loosen cover with wrench, then remove wrench, then remove by hand while holding by hand while holding tightly against spring tightly against spring pressure.pressure.

Check Valve RemovalCheck Valve Removal

Poppet style check Poppet style check valve.valve.

The poppet and The poppet and spring are free once spring are free once the cover is removed.the cover is removed.

Check Seat RemovalCheck Seat Removal

Check seats are Check seats are threaded into body threaded into body and o-ring sealed.and o-ring sealed.

A “special tool” is A “special tool” is needed for removal.needed for removal.

Check Disc ReplacementCheck Disc Replacement

Remove screw and Remove screw and disc washer from disc washer from poppet.poppet.

Reassemble in Reassemble in reverse order.reverse order.

Check Valve Reassembly NotesCheck Valve Reassembly Notes

Inspect and clean the Inspect and clean the guide bore on the guide bore on the cover.cover.

The stem must move The stem must move freely in the guide freely in the guide bore.bore.

Reassemble in Reassemble in reverse order.reverse order.

RV Cover RemovalRV Cover Removal

Cover is sealed by Cover is sealed by the diaphragm.the diaphragm.

Cover has a slight Cover has a slight spring load.spring load.

Hold cover firmly as Hold cover firmly as the bolts are the bolts are removed.removed.

RV Stem RemovalRV Stem Removal

Gently pull on the Gently pull on the diaphragm to remove diaphragm to remove the RV stem.the RV stem.

The spring should fall The spring should fall out when the stem is out when the stem is removed.removed.

RV Seat RemovalRV Seat Removal

The seat is threaded The seat is threaded into body and o-ring into body and o-ring sealed.sealed.

A “special tool” is A “special tool” is needed to remove the needed to remove the RV seat.RV seat.

RV Stem DisassemblyRV Stem Disassembly

Remove the retaining Remove the retaining screw.screw.

Pull the disc retainer Pull the disc retainer and stem apart.and stem apart.

RV Rubber ReplacementRV Rubber Replacement

The diaphragm and The diaphragm and seat disc are free seat disc are free once the stem is once the stem is disassembled.disassembled.

Replace rubber in Replace rubber in reverse order.reverse order.

Lubricate plunger o-Lubricate plunger o-ring on stem.ring on stem.

RV Reassembly NotesRV Reassembly Notes

Reassemble the stem Reassemble the stem in reverse order.in reverse order.

Position spring in Position spring in body.body.

Make sure diaphragm Make sure diaphragm does not cover hole does not cover hole for sensing line.for sensing line.