TR2/3/3A Clutch Slave failure

[Frank_D]

On a recent road trip my aging Girling Slave cylinder started leaking at the back end. It drained the reservoir to the point where clutch would not disengage. Managed to obtain some Dot 4 and topped up. Did not have to bleed it but some pumping pushed what air was in the system through the leaking area. Managed to make the long drive home in 4th with overdrive. Ordered a new slave and SS flex hose from the usual supplier. Did the install on a friend’s hoist which went very well including the bleeding process.

Have driven about 400 miles on the new Slave Cylinder, but had to do subsequent bleeding a few times during that period. Replaced the copper washer in the new flex hose, no indication of leaking at any connections from reservoir and master cylinder. It appears that the new slave cylinder has failed. Subsequent bleeding while on the road gave a “frothy” appearance to the Dot 4 at the bleed nipple. During the bleed process there were brief periods where there was descent feel to the clutch pedal but that was short lived. Pedal goes to the floor now with literally no resistance. Flat bed to home.

The original Girling body is sitting on my bench with a repair kit beside it. Have not ever done a rebuild. Advice on the symptoms of frothy Dot 4 and doing the rebuild would be appreciated.

Frank D…

 

[2002S2000]

From one with much less tenure, I would consider air in system as a possibility and I would continue to bleed at all points until a complete fluid change is probable. Then I would revisit the new slave. Also, flexible hoses seem to be a possible trouble spot as well although I've not experienced that. Good Luck!

 

[sp53]

Yeh the rubber seal inside the slave cylinder is shot. Put a new rubber seal inside the piston by removing the clip on the end. Make sure you have the rubber the correct way. They can go on 2 ways. The correct way is the most difficult way to push it in to make the seal. Some have a spring that fits in the back of the cylinder.

In addition have a look inside the cylinder to see if it has been scare by the piston. Use brake fluid for lubricate.

Once it is all back together, put it back on the car and let it gravity bleed for an hour or so with a hose on the zerk fitting going into a pickle jar or something like that and with the zerk fitting open about one turn. I usually put an inch of fluid into the jar to keep the hose tip under the fluid to make a seal for bleeding. That way I can pump and peddle bleed also if the gravity bleed was not enough.

STeve

 

[charleyf]

Your description of the frothy appearance of the brake fluid leads me to believe that the cause is not the slave at this point now but rather the master. My thinking is that the slave does not generate any activity which would cause air to get into the system. That would come from the activity (Pumping) at the master cylinder. The slave simply sits there and reacts to whatever the master cylinder initiates. That is as long as the slave continues to hold fluid.
A friend and I had a similar experience with a slave cylinder failure. His remedy to get the system going again was to use a light pressure to the master reservoir. He simply put a bicycle tire valve onto the top of the cap and gave it a few pumps with a hand pump while bleeding the slave cylinder.
Charley

 

[Frank_D]

Here is an update on my small issue. We probably all remember the expression “you have to prime the pump”. Charley, you were bang on with your assessment and thank you. The master is just a pump and had probably been voided of fluid during some of the work and efforts to bleed. This morning i used my one person bleed device and sucked about 1/3 of a litre of fluid through the clutch system. Bubbles at first of course but after a while clear fluid. Locked up the bleed nipple, wiped up any Dot 4 dribbles and sat in the car. The pressure was back in the clutch pedal as it should have been and the push rod was moving as it should. Important lesson for me is, do it right the first time and save this, below, from happening. Thanks

 

[CJD]

Pretty car...glad you have it working!