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-   -   Another bleeding clutch thread (sorry) (https://www.the75andztclub.co.uk/forum/showthread.php?t=266915)

bigblue75 7th May 2017 19:52

Another bleeding clutch thread (sorry)
 
There have been numerous threads on the clutch and having read through a few of them have come to the realisation that there are many opinions as to the correct way to troubleshoot and fix problems.

Noticed my two and a half year old / 48k miles clutch was biting very low and juddering occasionally as I pulled away so having read through various threads checked the fluid in the master. There was some but not much and there was a lot of fine black residue in the reservoir.

Picked up a litre of comma brake and clutch fluid and an eesibleed and earlier today removed and cleaned the master pushrod, cleaned the pushrod cylinder and reassembled. I then uncoupled the quick connector and ensured the clutch pedal was solid to prove the master was good. I used the eesibleed at 16 p.s.i and ran fluid through the master til it ran clear. It took around 500ml to clean out the master to quick coupler section and give a few seconds of clean flowing fluid. The fluid removed looked dull and cloudy with just visible bits of debris.

A bit wary of bleeding through the slave (after reconnecting the quick coupler) in case I ran out of fluid, I decided to top up the master and do that another time.

Battery back in car, all rags, tools and spare wheel away decided to test the clutch.
To begin it was worse!
Could not put in gear with my foot to the floor.
Repeatedly putting pedal to floor, trying first, lifting off , pedal to floor, trying reverse, lifting off enabled gear selection after 20 or so attempts. repeated this til gears changed easily but still had the very low biting point.
Took her for a run to see if any improvement but five miles and a hundred gear changes later still a very low biting point. The top 40mm pedal travel does nothing really.

As said, will bleed through the system from master through bleed nipple and top up level at master. After bleeding through - is it best to try to fill under pressure at the bleed nipple? If so what is the best way to do this?

Thanks for bearing with me.

EastPete 8th May 2017 07:47

I agree that a full bleed through from the master to bleed nipple is the best next step - this should give you a good pedal with the Eezibleed, based on my experience. If there is a leak somewhere in the system, the low pedal will eventually return.

There are advocates of reverse bleeding on this forum -I have tried it a couple of times, but find it very difficult to avoid introducing an air bubble into the slave when attaching the syringe/tubing to the bleed nipple. I have been wondering about connecting up the Eezibleed in reverse to the bleed nipple, so you could push plenty of fluid through from the bleed nipple up to the master. This could get messy if you do not catch all the excess fluid at the MC end. If you had spare Eezibleed MC lid, or even an old MC lid (which you drill a hole in to take some plastic tubing), you could attach this at the MC end with the tube into a jar to catch the excess fluid. I haven't tried this as yet - these are just idle thoughts.

Good luck and let us know how you get on

Pete

bigblue75 8th May 2017 19:02

Working late today and tomorrow so will try full bleed through on Wednesday evening all else going ok.

Never really had a low pedal, had a very low biting point and was hoping that a bleed through would fix this by removing air (if any) and freshening fluid. Never sure whats going on in a hydraulic circuit and am wary of doing anything foolish enough to regret (pushing through debris, using too high or low a pressure, damaging pipework / couplings / parts, etc).

Thanks for replying and will let you know how it goes.
Other advice and suggestions welcome.

zaph 8th May 2017 22:06

I had similar problems, and it turned out master had died. The black residue makes me suspect you have similar problems. I think that gunk in the fluid is the bore of the plastic cylinder being worn away and getting deposited in the clutch fluid.

I replaced mine with a metal one and so far all seems well. Not sure if bleeding it is anymore than a sticking plaster. You also risk damaging the slave cylinder if the clutch fluid is getting contaminated.

bigblue75 9th May 2017 04:48

Contaminating the slave is my concern too. By bleeding to the quick coupling first I'm hoping to reduce the chances of this when I bleed through to the nipple.

If some dirty fluid has already crossed this point...

Not sure if the larger bits I flushed out could have worn away from the master bore- they seemed too big.
The general cloudy fluid seemed like it was very fine black particles so you may be onto something there though ( I'm no expert ).

Thanks for the input. Off to work.

Westonboy 9th May 2017 08:35

What is it with these clutches, they seem to be subject to gremlins that I have never had on any other car, my clutch played up a while back and resulted in my cdt being recovered by the rescue people. When I tried it the next day it was back to working perfectly, I then bled it and put about 250cc of new fluid through it and 6 weeks on it is still perfect with no sign of a leak, will it go on behaving, who knows, but I hope for the best and am getting the money ready for the worst. :}

FrenchMike 9th May 2017 17:28

Quote:

Originally Posted by zaph (Post 2489521)
I had similar problems, and it turned out master had died. The black residue makes me suspect you have similar problems. I think that gunk in the fluid is the bore of the plastic cylinder being worn away and getting deposited in the clutch fluid.

I replaced mine with a metal one and so far all seems well. Not sure if bleeding it is anymore than a sticking plaster. You also risk damaging the slave cylinder if the clutch fluid is getting contaminated.

Sorry ,all the rubber débris come fron the slave seal ....

http://rovermg1.free.fr/rovermg/thum...1tngTyAnJa.jpg

The root of all hydraulic problems IMHO:shrug:

Mike

bigblue75 9th May 2017 19:43

Thanks. Very enlightening photo.

Thought that the larger bits (visible to my eye as a speck) couldn't be from the master cylinder bore and the photo appears to support that.

Just home from work, cuppa made and then out to get out tools, crack the nipple and get the spare to 20 p.s.i in readiness for tomorrow night after work... and some stretching excercises.

bigblue75 10th May 2017 21:17

Filled the eesibleed and set up to bleed the clutch circuit from master to nipple. Spare tyre was at 16 p.s.i., tube into empty fluid container attached to nipple and my better half keeping tabs on the outflow...

The fluid didn't come out as steadily as previously from master to quick coupler but did run clear long before the (approx) 500ml had been fed into the master.

Stopped the fill by folding the tube from the eesibleed back on itself, tightened the nipple, topped up the master and then tidied the tools, rags, spare and torch away.
The fluid that I bled from the slave was not as cloudy or dull as previously but did look dirty. I noticed what looked like a circular bit of debris about 4mm across and I dipped in my index finger to pick it out so as to get a better look. It stuck to my fingertip and as I went to roll it between two fingers it dissolved at the slightest touch. I have no idea what it was, it looked dark grey to my eye.

Took her out for a run and biting point is around 40 mm from the bottom of the pedal and it seems like the top 20 mm of travel does nothing. before the bleed the biting point was the floor and the top 40 mm of pedal travel did nothing.

Not sure if another bleed through in around a month would do anything useful. Realise that it could be tomorrow, next week or next month when the clutch gives up the ghost... Maybe it would help prolong the life of the clutch to treat the flushing through as a 12000 mile service item?

FrenchMike 11th May 2017 06:55

Quote:

Originally Posted by bigblue75 (Post 2490467)
Filled the eesibleed and set up to bleed the clutch circuit from master to nipple. Spare tyre was at 16 p.s.i., tube into empty fluid container attached to nipple and my better half keeping tabs on the outflow...

The fluid didn't come out as steadily as previously from master to quick coupler but did run clear long before the (approx) 500ml had been fed into the master.

Stopped the fill by folding the tube from the eesibleed back on itself, tightened the nipple, topped up the master and then tidied the tools, rags, spare and torch away.
The fluid that I bled from the slave was not as cloudy or dull as previously but did look dirty. I noticed what looked like a circular bit of debris about 4mm across and I dipped in my index finger to pick it out so as to get a better look. It stuck to my fingertip and as I went to roll it between two fingers it dissolved at the slightest touch. I have no idea what it was, it looked dark grey to my eye.

Took her out for a run and biting point is around 40 mm from the bottom of the pedal and it seems like the top 20 mm of travel does nothing. before the bleed the biting point was the floor and the top 40 mm of pedal travel did nothing.

Not sure if another bleed through in around a month would do anything useful. Realise that it could be tomorrow, next week or next month when the clutch gives up the ghost... Maybe it would help prolong the life of the clutch to treat the flushing through as a 12000 mile service item?

Hi,for infos ,what i got after master (OEM) replacement:

http://rovermg1.free.fr/rovermg/thum...F5AR60Y0di.jpg

Mike


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