Yet another clutch thread!
Discussion
Hi All,
Threads about clutches and clutch related issues seem to be the flavour of the month, so I appologise in advance for starting another. However I can't find anything in and recent discussions that relates to my current dilema.
Regular viewers might recall my recent clutch shenanigans (see: http://www.pistonheads.co.uk/gassing/topic.asp?h=0...
So all of that was done and both the master and slave have been fine, until a month or so back when one morning I suddenly had no clutch. I bled and topped up the system, and all seemed good. Then last weekend at the Duxford Car show the same happened when it got to home time, so the proceedure was repeated. I've covered 100 miles or so since then and now it's gone again.
There's no pool under the car to suggest the slave has failed (thank god), but there is fluid in the drivers footwell. The master cylinder seal is good and dry so it's not that either, I remeoved the vertical carpet section at the end of the footwell which had a tell tail trail of fluid on the back of it. Back under the bonnet and I removed the black dome to find a trace of fluid eminating from the breather hole in the filler cap.
My theory therefore is this:
"The natural heat generated by the operation of the clutch system, combined with the proximity of the master cylinder and it's resevoir to the drivers side exhaust maifold is causing the fluid to boil ecessively. The resltant air in the system is pushing the fluid back up the system and eventually out of the breather. When the fluid then cools it re-absorbs some of the air and the fluid level drops to show the resevoir as empty". By now there's not enough fluid in the system to operate the clutch."
OK, so does that sound plausable, or am I going down a really silly route?
In desperation, I used Halfords DOT 5.1 to 'charge' the system after it's rebuild and have topped up with the same since.
If this is the problem, can I solve it by sourcing some really high performance racing spec fluid (purple silicone stuff)?
As always, I look forward to your replys.
Best Regards,
Olly
Threads about clutches and clutch related issues seem to be the flavour of the month, so I appologise in advance for starting another. However I can't find anything in and recent discussions that relates to my current dilema.
Regular viewers might recall my recent clutch shenanigans (see: http://www.pistonheads.co.uk/gassing/topic.asp?h=0...
So all of that was done and both the master and slave have been fine, until a month or so back when one morning I suddenly had no clutch. I bled and topped up the system, and all seemed good. Then last weekend at the Duxford Car show the same happened when it got to home time, so the proceedure was repeated. I've covered 100 miles or so since then and now it's gone again.
There's no pool under the car to suggest the slave has failed (thank god), but there is fluid in the drivers footwell. The master cylinder seal is good and dry so it's not that either, I remeoved the vertical carpet section at the end of the footwell which had a tell tail trail of fluid on the back of it. Back under the bonnet and I removed the black dome to find a trace of fluid eminating from the breather hole in the filler cap.
My theory therefore is this:
"The natural heat generated by the operation of the clutch system, combined with the proximity of the master cylinder and it's resevoir to the drivers side exhaust maifold is causing the fluid to boil ecessively. The resltant air in the system is pushing the fluid back up the system and eventually out of the breather. When the fluid then cools it re-absorbs some of the air and the fluid level drops to show the resevoir as empty". By now there's not enough fluid in the system to operate the clutch."
OK, so does that sound plausable, or am I going down a really silly route?
In desperation, I used Halfords DOT 5.1 to 'charge' the system after it's rebuild and have topped up with the same since.
If this is the problem, can I solve it by sourcing some really high performance racing spec fluid (purple silicone stuff)?
As always, I look forward to your replys.
Best Regards,
Olly
Does sound a bit far fetched but then if the cap is faulty then it is possible. I do know when I have had a leak that when cold there is very little clutch but after things warm up the clutch becomes normal. So things do expand in the system as it warms up.
Is your fluid level going completely? Are you sure the fluid in the drivers footwell is not from previously accidentally spilling it while topping up the reservoir?
You have checked for signs of a leak around the seal but did you check where the pipe connects? Maybe this has come loose!
Try covering the reservoir with some Talkum powder this should show up any signs of leaking.
Is your fluid level going completely? Are you sure the fluid in the drivers footwell is not from previously accidentally spilling it while topping up the reservoir?
You have checked for signs of a leak around the seal but did you check where the pipe connects? Maybe this has come loose!
Try covering the reservoir with some Talkum powder this should show up any signs of leaking.
Hi Mark,
Once again, thanks for your input. I spent some time this evening playing around with the clutch system. Bled it fully again and got loads of air out of it. continued to bleed and top up as I went. No leaks from the master, and the pedal firmed up nicely. I took a cursery glance under the car, and there it was! drip, drip, drip! I'm hoping it's one of the joints from the braided hoses onto the bell housing, but can't tell until it's up in the air. I'm not sure I can face stripping it all out again to replace the slave! Arrghhhh! Cerbs eh?
Olly
Once again, thanks for your input. I spent some time this evening playing around with the clutch system. Bled it fully again and got loads of air out of it. continued to bleed and top up as I went. No leaks from the master, and the pedal firmed up nicely. I took a cursery glance under the car, and there it was! drip, drip, drip! I'm hoping it's one of the joints from the braided hoses onto the bell housing, but can't tell until it's up in the air. I'm not sure I can face stripping it all out again to replace the slave! Arrghhhh! Cerbs eh?
Olly
Tell me about it!! I had a leaking slave for 6 months I just kept topping it up (luckily I didn't have to bleed it, just pump the pedal each time) It got so bad I replaced the clutch fluid with engine oil as it was thicker and wouldn't leak as quick lol Well it got me through the coldest part of winter. As soon as the weather warmed i changed my seals only for it to still leak. So had to do it all again. I was hoping to find some sign I had pinched a seal but I never did so still dont know why It leaked the second time around.
Remember if it wasn't long ago you did it last then this time will be quicker as the process and how to undo those awkward bolts will still be fresh in your mind. Also the bolts will be easier to undo as they wont have 'stuck' in place.
Remember if it wasn't long ago you did it last then this time will be quicker as the process and how to undo those awkward bolts will still be fresh in your mind. Also the bolts will be easier to undo as they wont have 'stuck' in place.
I hear you Mark! I was so careful with the reassembly of the slave cylinder and I'm sure I didn't knick the rubbers, which would make the whole thing infuriating!
As for doing it a second time, yep I'm well versed in all the inticacies of doing the job, I'm just not sure I can bear to go through it all again! At least this time there isn't the additional pressure of a deadline, although I'll endevour to get access to a ramp for a weekend as opposed to laying on my back under axle stands!
Oh well, here we go!
As for doing it a second time, yep I'm well versed in all the inticacies of doing the job, I'm just not sure I can bear to go through it all again! At least this time there isn't the additional pressure of a deadline, although I'll endevour to get access to a ramp for a weekend as opposed to laying on my back under axle stands!
Oh well, here we go!
Boatbuoy said:
I hear you Mark! I was so careful with the reassembly of the slave cylinder and I'm sure I didn't knick the rubbers, which would make the whole thing infuriating!
As for doing it a second time, yep I'm well versed in all the inticacies of doing the job, I'm just not sure I can bear to go through it all again! At least this time there isn't the additional pressure of a deadline, although I'll endevour to get access to a ramp for a weekend as opposed to laying on my back under axle stands!
Oh well, here we go!
Olly - I can't solve the problem of needing a ramp, but I can lend you space in the barn to do the job undercover if that helps you? As for doing it a second time, yep I'm well versed in all the inticacies of doing the job, I'm just not sure I can bear to go through it all again! At least this time there isn't the additional pressure of a deadline, although I'll endevour to get access to a ramp for a weekend as opposed to laying on my back under axle stands!
Oh well, here we go!
TVR PH'ers are some of the best people in the world! Where else would a complete stranger offer kit so freely for a common cause?
Nigel, thank you very much, that's exceptionally generous of you. I do have a family friend who runs the local garage. I may be able to blagg the use of one of his ramps for a weekend, that's obviously the most conveinient route. But if that doesn't work out I may well take you up on your offer.
I'll keep in touch.
Olly
Nigel, thank you very much, that's exceptionally generous of you. I do have a family friend who runs the local garage. I may be able to blagg the use of one of his ramps for a weekend, that's obviously the most conveinient route. But if that doesn't work out I may well take you up on your offer.
I'll keep in touch.
Olly
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