24 - 2
B Test Cylinder/Piston Leakage
1
Ensure that the oil temperature is at 50°C (122°F) by
using the hydraulic oil temperature probe detailed in A1.
2
Take the weight off the ram to be tested, in this example,
by positioning the backhoe with dipper vertical and
bucket on the ground.
3
Use a suitable pressure gauge
A
to blank off the
supporting port of the ram.
4
Disconnect the hose from the opposite port
D
and leave
the port open to atmosphere.
5
Apply a load to the suspect ram for example the boom
ram by raising the dipper to the horizontal as at
B
.
6
After the initial movement measure the pin to pin
movement as at
C
and note the rod movement over 10
minutes.
7
If rod movement is evident the ram is defective.
C Test Spool Leakage
Note:
The following procedure applies only to services fitted
with A.R.V.' s. Note A.R.V.' s are not fitted to loader lift,
loader auxiliary, stabilisers or to the bucket rod side service
except when a Rockbreaker is fitted.
1
Render the A.R.V.'s inoperative in the suspect service.
This is achieved by removing the A.R.V. and replacing
with a blanking plug (part no. 25/609901) and seal kit
(25/610301).
2
Re-check the piston rod movement as described steps
A1 to A6.
A.R.V.
Control Layout
JCB
ISO
Slew
- Right
B1
B1
- Left
A1
A1
Boom
- Rod
B2
B5
- Head
A2
A5
Dipper
- Rod
A5
A2
- Head
B5
B2
Bucket
- Rod
A6
A6
- Head
B6
B6
Note:
Bucket ram rod side ARV only fitted to machines
equipped with Rockbreakers.
3
If the rod movement is now acceptable the A.R.V. must
be at fault. The A.R.V. may only require cleaning and
then resealing. If dirt is evident, the hydraulic tank should
be drained and cleaned. It is recommended that when
re-filling the hydraulic tank that new oil and filter be used
to prevent further contamination. If the A.R.V. is worn it
should be replaced.
Section E
9803/3280
Section E
24 - 2
Issue 1
Service Procedures
A401470
A
B
C
380200
FIG 2
C
D
380201
