Caterpillar C317 — Master Piston Removal, Inspection and Installation
Maintenance
For the Caterpillar C317, from the Caterpillar service manual.
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Before you start
- The master piston return spring is contained inside the master piston. Do not disassemble the master piston assembly in the field.
Procedure
- Remove the anti-rotation pin assembly and lock washer from the housing.
- Remove the master piston assembly.
- Inspect the master piston for damage; the piston surface must be free of score or wear marks and must move freely in the housing bore.
- Compress the return spring using a pick or probe; while holding it compressed, insert a small diameter pin into the access hole and remove the probe.
- Insert the master piston into the housing bore.
- Install the anti-rotation pin with the lockwasher into the housing and remove the pin so the spring is retained.
- Tighten the anti-rotation pin with a 3/16 in. hex key wrench to 40 lb-in. (4.5 N-m); check piston moves freely.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Anti-rotation pin 40 lb-in. (4.5 N-m)
Source: Caterpillar service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.