37
7.3
Lay the pedestal on its side.
7.4
slacken the four screws (10) at each end of the manifold (4) to allow the 'O'
ring seal (8) to unseat and any residual pressure in the tank to exhaust. Remove screws (10) and
washers (9).
7.5
Withdraw the first stage piston (5) and the manifold (4) together from the bore of the first stage
cylinder.
7.6
Close the column to its lowest position.
7.7
Slacken two screws (17) and remove the cords (21) from cord clamps (19). Note the
arrangement of the cord in the clamp.
7.8
remove circlip (26) from the end of the first stage cylinder (6) to release it
from the ram plate (31).
7.9
Remove eight screws (32), separate the first stage ram plate (31) from the column bottom tube
(33) and allow it to hang on the chains.
7.10 The second stage cylinder (4) and the first stage cylinder (6) may now be withdrawn from the
second stage ram plate (34).
7.11 Service the ram assembly as necessary. Referring to
, fit new 'O' ring seals throughout.
Pack between bearings and coat walls of piston and cylinders with Chesterton white grease No. 622
Safety valve, charging valve and pressure gauge
8
To replace a defective safety valve, charging valve or pressure gauge proceed as follows:
8.1
Connect nitrogen charging equipment to the charging point and completely depressurize the
pedestal.
8.2
Remove the defective item and replace with new or serviceable item. Fit new bonded seals.
8.3
Charge the pedestal
8.4
In the case of safety valve replacement refer to
8.5
Carry out leak check
.
