Clutch Master Cylinder (No shim required)

[FC0058]

I recently had to re-kit my slave cylinder so thought I may as well do the lot including re-kit the master and replace the flexible hose.

I dismantled the lot and cleaned everything replaced the cups and other parts and put it all back together, I noted that my master had an additional part not shown in the manual , it was a brass shim located between the piston and and primary cup. "I thought should I leave it out or put it back, It was there before so I put it back. Well what a mistake that was took me for ever to bleed (with help) and after a week of driving my peddle was almost non existant again.

Hmmm thought, slave looked OK when I pulled it apart but was old, Master was in great nic so could not he that, "replacement slave only $51" so I ordered one, replaced it Saturday and system would not bleed. Hmmm that shim still annoyed me so I checked all my manuals, Nasco cattle dogs again, called a couple of mates. General feeling remove the shim.

Shim removes and the system bled like a cut femoral artery.
Lesson 1 trust your feeling and instincts,
Lesson 2 Manual must be right,
Lesson 3 take better care of your car (7 almost 8 years and this is the first time I have looked at the clutch),
Lesson 4 Brake and Clutch masters are different so do not mix and match parts.

Cheers Jim (the negligent FC owner)

[KFH]

When I rebuilt my clutch master I had a stainless sleeve put in it.  The firm that did the job also reassembled it.  I could not bleed the system no matter what.  The rubber hose was new slave was almost new.  Took the master back to the repairer who dismantled it and reassembled it.  Nothing wrong was found.  Still would not bleed correctly. Eventually I made cap for the reservoir so I could apply a small amount of pressure to it.  Presto problem solved. No brass shim in it when I dismantled it.

Keith

[collecta]

 Best way to bleed clutch hydraulics on most makes is to gravitiy bleed. fill the reservoir cracked the slave bleed nipple and and let gravity do its job, once it flows without air bubbles shut of the bleeder job done. Some did come from new with brass shim this alone will not stop bleeding of system, Jims right they dont show it in the workshop manual but there is a pic in my parts manual exploded view.

cheers
Scott

[FC0058]

Leak from slave fixed with a little more muscle applies to tighten hose and bleed nipple, now its weeping from the master, does this saga ever end.

I re-kitted the master so am a little frustrated. Hrrrrrrr

Jim

[FC0058]

Hi all
Weeping master fixed, it ended up being the secondary cup v after market piston. I took it to PBR who were of great assistance and replace the cup with the right one.
Also to note they recommend that the shim between the piston and primary cup be retained.

Cheers Jim

[87 velo]

Just a tip, I reverse bleed, instead of trying to make air bubbles go down and out at the slave cylinders or calipers, I put the fluid in through the bleed nipples.  Get a big syringe from the chemist (you might get a funny look when you ask for one!!) fill it with the appropriate fluid fit a hose onto the syringe to join it to the nipple open the nipple and just push it back into the system, gets you a pedal real fast and you don't have to prime the master cylinder first.

Another advantage is you find out fast if the compensating/relief port is blocked (small port in master cylinder) because you can't push the fluid up, when this blocked. (usually because there is no free play on the push rod)  Also you don't use much brake fluid and it becomes a one person job!! Although sometimes to finish off I give it a couple of pumps through the conventional way.

If the compensating/relief port is blocked is blocked you can often bleed it conventionally but you will find that the brakes/clutch may stay applied as fluid cannot return to the master cylinder.

If you give this a try, leave the cap on loose on the master cylinder as you don't want brake fluid squirting over your paint!!  Also if your vehicle has drum brakes all round it will have a residual line pressure valve in the end of the master cylinder, which means you will have to push harder on the syringe to get the fluid up as you have to generate a bit of pressure to open the valve (haven't tried with drum brakes but should still be possible, I've got discs)
Good Luck Mick