lost clutch pedal pressure this morning....

[coanda]

As the title says really....I went to drive off and the clutch pedal has virtually no spring/pressure in it. Looked at the reservoir and there is very little fluid left. I did see if it was driveable but low speed gear changes are verging on impossible.

Where is the most likely place for a fault?

The master cylinder and reservoir look ok but havent had chance to check the release cylinder and hosing as I had to get to work. This has got suddenly worse overnight with the gear change being a bit picky in the last week or so.

Thanks for looking!

[kaiowas]

A slow leak from the slave cylinder is most likely. Then once the reservoir runs dry the next time you press the clutch a slug of air is drawn in and the pedal goes all spongy. As a quick fix a refill of the reservoir and bleeding the clutch will get you mobile again then you can just keep an eye on the fluid level until you get chance to fix it properly.

[coanda]

Thanks Kaiowas....that was the conclusion I was coming to...I have ordered a slave cylinder from brakes int which should be here tomorrow. Hope I don't find its the tubing or something I'd missed on the master when I get home! On the other hand....new parts can only be a good thing on cars this old!

[coanda]

Right then....

Part turned up nice and early thanks to UPS and Brakes Int...

Turns out that this Japanese car is made for Japanese size hands and spaces! The manual say's to use an SST which to me just looks like a short handled 12mm spanner. If I'd had an old 12mm spanner I'd have halved it's length. There's all sorts of pipe work and bracketry that make a space just big enough to get a spanner and a hand in there. I did make life slightly difficult for myself by leaving the bleed tube fixed to to the car. When I'd finally got the pipe connections undone and the two bolts removed from the car (the cylinder is clamped between the block and a big thick bracket) I was able to remove the cylinder. There were no obvious signs of leakage, but then the system doesn't have much of a capacity anyway. I took the rubber boot off to find it was filled with brake fluid. So there's the problem! Removing the piston showed a couple of things....firstly the spring connected to the piston had broken one wind up from the bottom. This left the majority of the spring intact, but meant the spring was off centre and compressing at an angle. This then led to some very obvious wear marks on one edge of the piston. I suspect the piston became the sacrificial component rubbing against the cylinder housing and a leak had developed through the seal over time. The spring was also very brittle. By this time a friend had popped roud for a nose, and we spent the best part of the afternoon trying to put the replacement cylinder back into the car. The hose connections just would not have it. We got one in but the bleed valve just wouldn't thread. So, after he'd left I decided I'd take the cylinder back out, remove the internals, boot and clutch piston rod and put it all into the old cylinder housing (keeping fingers crossed that there's no uneven wear in the cylinder bore, or that it's not too bad if it is - couldn't see any but we'll find out soon....). This time it went back in a treat, so the threads on the replacement lucas cylinder were carp and I am going to try and get a replacement housing from brakes int. I decided to leave the bleeding of the system till tomorrow. More fun awaits!

Cheers

Coanda

[phil mk1]

Good time for clutch slave sylinders mine went right out side my house how lucky is that ? got a new one from TCB parts in cornwall fitted and bled in 1.1/2 hours jobs a goodun cheers phil

[coanda]

1.5 hrs! nice! All this mech work is new to me so I am taking a long time over simple things......and I spend ages dithering over whether the axle stands will hold if I use them.....I hate getting under the car!

ETA....

Finally finished bleeding it...works a treat! yay!