Mk2 clutch hydraulics question

[paggers]

Yesterday I finally finished the sill welding on my Mk2 project car and for the first time in 15 months it is back on all four wheels. I decided to check that everything was working as expected but when I put my foot on the clutch the pedal goes straight to the floor with no pressure whatsoever. Definitely a problem!

Bleeding the system looks fairly straightforward but I'm curious as to why all the pressure has disappeared. Is this something that is to be expected after over a year of sitting or should I be looking for a leak somewhere?

[nedski]

It's a bit of both. I would do just what you are thinking. Bleed the system and check for leaks anyway. Cylinders can corrode and the rubber seals inside can perish. Suck it and see as they say, if there are no leaks and it works ok then happy days.

[The Captain]

Check the clutch slave cylinder, you will see if that has perished by the fact that there will be clutch fluid leaking.

[Mazda Mender]

For the sake of what they cost ,just fit a new one and fresh fluid buddy.
M-m

[The Captain]

For the sake of what they cost ,just fit a new one and fresh fluid buddy.
M-m

[paggers]

Thanks for the feedback chaps. I'll order a replacement clutch slave cylinder as suggested, if the system is totally drained anyway then there is no real downside other than a minor outlay and a bit of extra work.

[paggers]

So I bought a replacement slave cylinder as suggested - I went with a pattern one from MX5parts, rather than an OEM one. When I took the old one off the boot was full of manky clutch fluid so all good, definitely leaking. But once the system was all put back to rights I couldn't get any pressure in the system no matter how hard I tried. So in the end, in complete frustration, I pulled the clutch master cylinder off the Mk1 scrapper and swapped that for the one in the Mk2. After that I got pressure and was able to bleed the system in no time.

Got to wonder what are the odds of both master and slave cylinders going but I guess the car has been sat for 18 months so anything is possible.

So after all that the car finally moved itself forwards and then backwards, the first time it has moved under its own power in 18 months. It was a great feeling. Next I have to re-bleed the brakes as the pedal goes all the way to the floor on the first push then firms up nicely after a couple of pumps. These damn hydraulics are causing more trouble than almost anything else on the car!

[nedski]

What are the odds eh. That's what they do, send things to try us. Well done though you didn't give in.

It happens fairly regular to be honest. Without use everything corrodes and the rubbers stick inside etc. Vauxhalls used to give hassle when bleeding brakes. The pedal would move up and down on the same spot for 5 years and wear a ridge along with leaving gummy deposits. Then one day you change your brake pipe and try bleeding up. The rubber seals are suddenly rammed right down the cylinder into this ridge of crap when bleeding and bang go the seals. Sometimes bleeding using only half the pedal travel will save a cylinder.

[DavesBRG5]

Mine was the same!

Clutch master cylinder failed (leaking on to the drivers footrest) but we couldn`t bleed a decent pedal without fitting a new slave cylinder too even though it showed no sign of leaking.