Clutch mystery solved but now more questions......

[terryp]

Well I have a car that works albeit only when cool. When the car gets up to normal working temp it's a little difficult to get into reverse.
I am running Automec Silicone brake fluid and I wondered whether that would make a difference. I have made a heat shield for the slave cylinder but have taken a temp of the header pipes at 220 degree centigrade after a run. Is this too hot. It all seems very hot under the bonnet , much more than a +2.
Would a longer adjustable push rod for the master cylinder help.
I think I only need a nats whisker!

Thanks
Terry

[patrics]

Hi Terry,
I don't think you will get that to work, above 100degC that fluid becomes very compressible but your real problem is how to get rid of it.
If your rich buy a new master cylinder, slave cylinder and pipe work and fill with a standard approved brake fluid.
If not pump out the fluid strip down the master cylinder and slave and clean the best you can with a suitable brake cleaner. If possible renew pipe work and fill with an approved fluid.
Sorry not what you probably wanted to hear.
I don't know of a brake or automotive company that will approve the use of that fluid in any system.

Cheers
Steve

[rgh0]

Hi Terry
What sort of clutch pipe do do have ? is it the red plastic tube version or is it some other arrangement. The red plastic ones can swell under pressure when hot and combined with the greater compressibility of synthetic fluid compared to normal DOT3 fluid could give your symptons.

220degrees for the header next to the slave cylinder is about normal I think.

cheers
Rohan

[terryp]

I have a one piece aeroquip hose?
Is there any more heat shielding I can do before changing everything or certainly taking it all off and washing all the parts?

Thanks
Terry

[rgh0]

Hose should be fine, must be the fluid I guess.

If you have shielded the slave cylinder and the hose going into it from direct heat from the exhaust then it should be OK.

You should be able to flush out the synthetic fluid with a few changes of normal Dot 3 fluid without needing to dismantle it all. Pump the level low in the master cylinder - refill with normal then pump low again. Repeat for about a litre of fluid and the system should be fully changed over. The synthetic is lighter than the DOT 3 and you may have some floating on top in the master cylinder as you do this procedure and not going out through the system, so suck it of with a syringe if you have this happening.

cheers
Rohan

[terryp]

Thanks Rohan , I'll run the car for a while in case its not a coincedence and its just the clutch plate freeing up on the splines like we said previously. I had silicone in my +2 and never had a single problem but if its not sorted by the end of the summer I will change to Dot3/4 as your method and see if that cures it. Its not really a problem , only parking at the end of the journey!

Cheers
Terry

[rgh0]

HI Terry

turn the engine off - put in reverse - restart

Used to work on my Esprit. They were notorious for the problem due to the long red plastic line they had
Fixed it with a braided stainless line.

cheers
Rohan

[terryp]

Problem solved! Thanks Rohan

Terry

[mbell]

On a side note when I fitted a full length flexible clutch line on my car I placed a 4" of silicone/fiberglass heatshield sleeve on the hose near the exhaust.

Haven't had the car running for more than few minutes so don't know how successful or not it is but I had the heatshield for the fuel line and the clutch line off. So seemed a sensible thing to do.

[terryp]

EPILOGUE,

Well after changing the fluid, fitting an adjustable push rod and time seems to have cured the problem.
When I scoped inside the bell housing there was a log of blue paint, which was the colour on the centre of the drive plate from Sue.
The moral is that when you fit a clutch make sure the drive plate can perfectly slide on the splines.

Terry

[nmauduit]

So it wasn't the fluid in the end : I'm glad since I'm using the automec DOT 5 for my clutch , on the assumption of their claim of a boiling point of 260?C...

[terryp]

It may have made it slightly worse but not in a significant way.
Terry

[alan.barker]

as far as i know Silicone fluid has a boiling point 30?c more than dot4.