Selecting this service jcb service manual chomikuj that the pressure vents through the un loader and not an A. The maximum reading should be as specified in Technical Data.
4 If the pressure is incorrect, slacken locknut E and adjust cap F. When the pressure is correct, tighten the locknut. 41-31 for shim description and location. Note 2: The illustration shows the unloader pressure test connector D fitted to the loader valve block. If the pressure is incorrect, the A.
The numerical sequence shown on the illustration is intended as a guide to dismantling. For assembly the sequence should be reversed. Each of the identical load hold check valves 4R to 4W can be removed as shown at 4W. 4X is a smaller size but otherwise identical.
Ensure good condition of seating faces on poppets 4 and 8 and on the mating faces in the valve block. Spools 4A, 4B, 4E and 4F are identical but must not be interchanged as they are matched to their bores. Stabilizer spools 4C and 40 are identical to each other but different from the excavator spools. All spools have the same centring and sealing components items 9 to 21. To prevent spool rotation when turning screw 15, hold a rod through the eye end of the spool. If only renewing the seals, dismantle as far as cap 14 then remove items 15 to 22 as an assembly. Apply JCB Lock and Seal to threads of screw 15.
For dismantling and assembly procedure see page El43 -4. Note: Valve 4Q is only fitted to machines equipped with a Powerbreaker. Dismantle sub-assembly 14 into its component parts. Make sure that small drilling A is not blocked. Discard old and worn O-rings and back-up rings. Renew all O-rings and back-up rings. Lubricate O-rings and back-up rings with JCB Hydraulic Fluid.