There is good and bad news associated
with doing this job. The good is that the repair
is extremely easy to accomplish. The bad news is
that there are two ways to get at the
slave...the hard way (from inside the cockpit)
and the harder way (from under the car). This
story illustrates the procedure.
Socket sizes are in red
after the item it fits.
Tools
Required:
Phillips screwdriver
large flat screwdriver
socket wrenches
open-ended wrench
brake fluid
slave cylinder rebuild kit
DOT4 brake fluid
Optional:
new slave cylinder
Removal
First remove the left seat. This is done by sliding the seat all the way back and taking out the two bolts (7/16") at the front of the tracks. The rear of the tracks has two bolts that can be reached by sliding the seats all the way forward. Lift out the seat.
All the trim pieces around the transmission tunnel must be removed. Take out the four bolts holding in the tunnel cover and the two screws holding on the knee pads. Next remove the lower dash support. It is held in place at the top two screws (Phillips screwdriver) and at the bottom by four bolts (1/2"). Remove the
shift knob.
The carpeting covering the transmission tunnel can now be lifted out of the car.
At this point you might notice a "window" cut into the side of the transmission tunnel. Often enterprising (lazy) previous owners will skip the the next step and simply cut a hole in it. This is not a good plan as this hole will be problematic in the future. Moisture and heat will have easy access into the interior, aimed directly at your legs. So, resist the urge and just remove the transmission tunnel. It is held in place with 4 set-screws on each side and four on the back against the firewall (8mm).
The slave cylinder is now easily accessible.
Start by loosening the bleed valve
(7/16"), draining
the system and the remove the valve. Remove the
hydraulic pipe
(7/16") and push it clear of the
cylinder. Completely remove the
locating bolt, nut and washer
(1/2"). The
cylinder may be difficult to slide out. A large
screwdriver wedged into to slot in the side of
the housing should help loosen it.
While
it is out...
there are some things that you should
consider doing while you have access to this
area.
Change the Transmission fluid
Drain the fluid out of bottom and replace
the plug. Open the filler plug on the right side
to transmission and fill until fluid just
trickles out.
Reinsulate Transmission Tunnel
After a while the insulation inside the
transmission tunnel rots away or falls out.
Staple or glue in new insulation. Don't forget
that it will be exposed to the elements so
waterproof it with plastic sheeting.
Rebush the shifter knob
Shifter getting sloppy? Rebush it. The parts
can be purchased individually or as a kit.
FYI
Oil Capacity
without overdrive 1.8 pints, .85l
with overdrive 2.85 pints, 1.35l
Torque settings
Drain plug: Mk4-20ft/lbs, 1500-25 ft/lbs
Filler plug: Mk4-20ft/lbs, 1500-25 ft/lbs
Inspection
Remove the dust cover retainer and the dust cover. The retainer may require a pipe wrench with a gentle twisting motion while pulling for removal. Next remove the circlip The plunger will either side out easily or can be helped along by tapping the whole cylinder against a wooden surface. Remove the spring. Clean all parts thoroughly with brake fluid. Never use gasoline or other petroleum based solvents as they damage rubber.
The first thing that needs to be determined
is whether the cylinder is repairable. Carefully
inspect the rubber parts. If there any splits or
cracks, there is a good chance that all that
needs to be changed is the rubber. Run your
finger inside the cylinder feeling for scratches
or pitting. If there is minor scratches, try
using a fine steel wool the buff them out.
Thoroughly wash the inside with brake fluid to
remove ALL traces of metal flakes. If the pits
are too deep a new cylinder must be
purchased.
Rebuild
Rebuilding is a rather easy process. I have
never read it anywhere but I have found that
soaking the rubber parts in brake fluid for
about a half hour softens them. Start by fitting
a new rubber seal to the plunger with the fat
end away from the metal end. Insert the spring
fat end first. Wash the inside of the cylinder
with brake fluid then insert the plunger rubber
side first. Fit the retaining spring, dust cover
and then the cover retainer.
Refit
When refitting the cylinder, start by
centralizing the push rod in the housing. Push
the slave cylinder into the housing with the
push rod going into the dust cover. Line up the
grove with the hole and place the bolt in
through the top hole and tighten the nut.
Note the locations of the bleeder and pipe. The
bleeder MUST be on top (see photo below) or bleeding the system will be nearly impossible.
Bleeding
the System
The
process is so easy that you forget to check the
fluid level. Ask an assistant to monitor the
lever while you work. Start by filling the
reservoir with new, clean DOT 4 brake fluid*.
Next place a small, preferably clear tube on the
bleed nipple. Put the other end of the tube into
a cup partially filled with fluid. Loosen the
nipple one turn. Depress the clutch pedal fully
and let it return without assistance. Repeat
with a few second pause between depressions.
Notice the fluid going into the cup. When a
solid stream is emitted from the tube without
any air bubbles, hold the pedal to the floor and
tighten the nipple. The clutch pedal should feel
firm and clearly disengage the clutch. If not,
repeat the bleeding process. Don't forget to
check the fluid level.
Refitting
Everything Else
Refitting all the interior parts is done in
the reverse order that they were removed. Easy
huh?
*DOT 3 brake fluid is made for American rubber and will eventually "melt" the rubber in your British system. DOT4 (Castrol LMA GT) is factory spec. Castrol LMA is still available at most larger auto parts stores.
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