Keep losing my clutch after long motorway journeys?

[kev8611]

Took the car to Glasgow and back on Saturday for its first long run, 200 miles approx everything went great however there was a slight problem with my clutch.

Around town or short journeys when it is being used, the pedal stays firm and all works fine, Put 10 to 15 miles on the motorway at 70mph and I lose the pedal and cant get any gears. I need to pump the clutch a few times to get the pedal back. Happens every time I sit at 70 for any length of time.

I am thinking there is heat from the exhaust/turbo nearby the slave cylinder that is boiling the fluid in the pipe, but then it is ok when I drive the car quite hard which I thought would produce more heat there than sitting at 70 will

Anyone had this before? what are the fixes? 5.1 fluid? braided line or heat shield?

Thanks

[jakeymears]

Is the level dropping in the master cylinders reservoir ?

[kev8611]

No it remains the same. As I say the clutch works fine most of the time.

[SonicSW20]

Air in the system, perhaps?

[ashley]

When did you last change the fluid? Sounds like a sensible starting point

[kev8611]

fluid was changed and system was pressure bled at the start of february along with brake fluid. The car basically had a full service before it was out on the road few weeks ago

[SonicSW20]

Bleeding the system is the first place to start then if it was fine before the fluid was changed.

[kev8611]

yeah but its been bled recently. If there was air in the system I wouldnt have a clutch permanently

Worth mentioning, its the first long journey its done since new turbo kit etc (gt3076)

[ashley]

What fluid did you use when you serviced it?

Worth inspecting the flexi clutch hose to the slave cylinder- any sign of it ballooning? Does it look like it's getting hot?

[2mad]

Master or slave on the way out .. this was my first mr2 fix .. probably master .. but never rule out the slave .. investigation time mate .

Or air in the system



Took me 3 weeks to diagnose mine .. proper tricky .

[Peter Gidden]

If you're happy the system is bled properly, i'd say the master cylinder seal is failing. And overhaul kit from Toyota should solve the problem.

If it was the slave cylinder, youi'd have fluid leaking at the dust cover.

[kev8611]

What fluid did you use when you serviced it?

Worth inspecting the flexi clutch hose to the slave cylinder- any sign of it ballooning? Does it look like it's getting hot?

Dot 5.1

I havent had the chance to get under and look yet but once I get time I will check the hose etc, I would have thought the heat is doing something to it. If it was air in system or a cylinder fault it would be there all the time?

Even going out to the garage after not using the car after a day or 2 it seems fine. But only after a long stint at 70 it gets soft.

Does not seem close to a heat source but then I have not been near it when the car is up to temp and checked how much heat is held in that area. Downpipe is no closer than the standard one and its ceramic coated.

[kev8611]

Think I will double check the bleed, if thats fine then I will overhaul the master cylinder, atleast I can rule out anything at the front end of the car

thanks