Rolls-Royce Silver Spur 1985 Service Schedule Manual page 202

B5·18
valve and the trailing arm from which it was removed.
Adjust the joint to obtain complete movement
without free play.
Brake and hydraulic systems
WARNI NG
Use only Hydraulic System Mineral Oil (LHM) to
replenish the braking and levelling systems.
!Do not use Brake Fluids {Castrol RR363,
Universal, or any other type). The use of any type of
brake fluid, even in very small amounts. will cause
component failure necessitating extensive rectification
to the braking and levelling systems of the car.
Always ensure before fitting any seals, hoses,
pipes, etc., that they are suitable for a mineral oil
system. For details of correct component identification
reference should be made to Chapter G of the
Workshop Manual.
Always ensure that a sealed container of
Hydraulic System Mineral Oil (LHM) is fitted
adjacent to the battery.
Always ensure that no foreign matter enters the
systems when work is being carried out.
In order to protect against claims of liability for
hydraulic system contamination. it is recommended
that the hydraulic system mineral oil is tested for
contamination prior to work being undertaken,
preferably in the presence of the owner or his/her
representative.
It is important that the test is carried out even
when the hydraulic system mineral oil is to be
renewed as this will not prevent the deterioration of
components which have been in contact with
contaminated mineral oil.
Brake fluids and mineral oil are immiscible and
with large amounts of contamination separation of the
Fig. B5·29 Height control valve actuation link
joints
fluids will occur on standing, due to the greater
density of the conventional fluids. A further indication
of the mixing of conventional brake fluid and mineral
oil is its cloudy appearance.
To carry out contamination tests a kit is available
from Rolls-Royce Motors Limited, part number
RH 2841 and should be used as follows.
Switch on the ignition and depressurize the
hydraulic systems by pumping the brake pedal until
both low pressure warning panels illuminate. Continue
to pump the pedal for at least a further
20
applications
to ensure that all the accumulator mineral oil is
returned to the reservoir.
Clean the area around each hydraulic reservoir
filler cap and then remove the cap.
Ensure that the components in the test kit are
clean and dry.
Using the sampling tube provided, extract 50 ml
of mineral oil from the top and bottom of each
reservoir.
Place the samples into the individual clean dry
containers.
Shake each sample taken to ensure it is well
mixed.
Pour 10 ml of each sample into clean test tubes
(do not mix the samples together).
Using the dispenser, add two drops of the red dye
solution contained in the kit into each 10 ml sample.
Cork the test tubes and shake them thoroughly.
Leave the samples to settle for at least 30
minutes.
Examine each sample.
Sample diagnosis
On adding the red dye solution and the subsequent
mixing. the green colour of the mineral oil will change
to a reddish brown. This does not indicate
contamination of the hydraulic system mineral oil.
Contamination can only be confirmed by the
formation of a cloudy red mass which will begin to
settle towards the bottom of the tube if left to stand
for at least 30 minutes.
If the sample in the test tube on addition of the
dye turns red but remains clear it indicates that the
sample is not contaminated.
The volume of red mass which will eventually
settle to the bottom of the test tube indicates the
amount of contamination within the hydraulic system
mineral oil.
Complete separation of the two liquids may take a
considerable amount of time. for example a very small
percentage of contamination may take more than
seven days to completely separate.
If contamination is suspected, a more thorough
test can be undertaken, details of which are given in
Chapter G of the Workshop Manual.
. If contamination is suspected, but ditticult to
diagnose, due to the small amount of contaminant that
may be present, or any doubt exists, confirmation
should be obtained by sending a sample to Rolls·
Royce Motors (if in the United Kingdom) or to a
chemical analysis laboratory.
July 1985