Help! Cant bleed the clutch on my E30!

[c.robertson00 11]

So my clutch master cylinder was leaking on my E30 and I replaced it then tried bleeding it. First i tried the normal two man way and got nothing. I then got a one man kit with the one way valve and had no luck. Then made a vacuum unit using a jar and some pipes to suck it thru using the engine which i have used with success before on an E30 and still had nothing. I replaced the slave cylinder after all that and tried again and im left with a spongey pedal that doesnt engage the clutch.

What could be wrong?

Cheers,

Chris

[1rotty 40]

Hey Chris..are u sure u havent damaged the masters piston or seal with all the pumping...made that mistake once myself

[leithcm 0]

Another trick to try. Get a large syringe - about 20 mil is a good one - attach a rubber line to the business end, and fill to the top with brake fluid. Gently push the plunger in until ALL air is expelled. Then carefully place end of rubber line to the bleed nipple of the slave cylinder, the open nipple. GENTLY push on the plunger to reverse flush the slave, then line, then master cyclinder.

Problem is the bleed nipple is not at the highest point so is bloody hard to get all the air out. I have used this method with great success. Pushing the fluid through takes all of the tiny air bubbles with it - but keep an eye on the master cylinder as you could overflow it! :-)

[c.robertson00 11]

Ill try the syringe trick and if that doesnt work ill pull the slave off and have a look to see how far its extending. Otherwise you could be right Mark and ill go get a new master cylinder. Its just so damn frustrating!!!

[Jay 735i 0]

Don't know if it's the same on the E30, but on my old E21 I could adjust the height of the pedal by fiddling with the adjuster behind the pedal itself.

Reason for mentioning this, is because I have just done the master and slave cylinders on my B2000. I could not, no matter what I tried, bleed the clutch afterwards. Then in a flash of genius... ok I looked it up on the interweb... I adjusted the pedal travel at the back of the pedal so that the pushrod for the master cylinder was able to move further out on full pedal extension (i.e. with no foot on it). What was happening was the pushrod wasn't coming back far enough to allow fluid to get into the system, basically the valve wasn't opening and there was nothing for the master cylinder to push.

It is apparently reasonably common, especially if you're using pattern, non-OEM parts, with the usual variances to OEM.

[_ethrty-Andy_ 2122]

i wouldnt d*ck around with it, and would just get a new master and slave and be done. you have to replace both at the same time because if you get a new slave and not master the added pressure just accelerates the wearout of the master. I found that out the hard way and would assume the opposite way round would happen too. they arent that expencive really. I tried for hours doing it when i did my first manual conversion... gave up with the inefficent 15 year old crap and got new stuff instead of investing in all the fancy self bleeeding tools etc. at the end of the day your going to have a better result. aparently BNT is cheapest, especially if you know someone that works there. I found that out after though so cant give accurate pricing

[c.robertson00 11]

i wouldnt d*ck around with it, and would just get a new master and slave and be done. you have to replace both at the same time because if you get a new slave and not master the added pressure just accelerates the wearout of the master. I found that out the hard way and would assume the opposite way round would happen too. they arent that expencive really. I tried for hours doing it when i did my first manual conversion... gave up with the inefficent 15 year old crap and got new stuff instead of investing in all the fancy self bleeeding tools etc. at the end of the day your going to have a better result. aparently BNT is cheapest, especially if you know someone that works there. I found that out after though so cant give accurate pricing

Thats exactly what I did they are both brand new and i still cant get them to bleed.

[_ethrty-Andy_ 2122]

Thats exactly what I did they are both brand new and i still cant get them to bleed.

sorry mate, missed that. thats very strange in that case as have never had an issue when using new parts. I refuse to bleed brakes, but clutch is usually pretty straight forward. are you sure the metal line isnt kinked somewhere along the way? is the only thing i can think of that might make it hard

[c.robertson00 11]

Yea ive checked all that. I might just drain the whole thing and start again.

[*Glenn* 854]

Give me a call in the morning Chris (09) 2722546

[Venatus 2]

When I first tried to sort mine out after getting the car from someone that had it sitting for six years it did this... I just kept booting the clutch pedal with the bleed nipple open for about 5 mins till fluid started coming out the bleed nipple. Sometimes it seems to take a while for fluid to work its way through the system, especially if theres a big dirty airlock.

Probably not very professional, but it worked for me...

[polley 916]

Have had brand new master cylinders that were crap, it was a certain brand, every replacement gave the same issue until changed to a different brand (was a cheap chinese type a lot of places sell these days, must of had a bad batch or some thing). Put a different brand in and it bled fine.

So just because its new, you can't assume it is in good condition.

Edited February 15, 2012 by polley

[slowe30 0]

after fiddling around for ages with mine and finally got it working. talked to a guy at my work (ex bmw mechanic/current mechanic) he told me due to the position of the bleed nipple you have to remove the slave from the box, turn it upside down compared to what it usually is, push the rod all the way in, then bleed as normal.

we have to do this on subaru legacys due to the same issue, worth a try.

btw with mine i put a slave on it that came with my new engine and box, bleed the system, tested and it just went to the floor, keep bleeding and did nothing, i then swapped back to my old slave that i had on my old box, put it on and checked it then, it felt great and worked fine, didnt evan bleed it to start with. then got it running and took it to work and used the vaccume bleeder from work on it and felt great still, maybe evan a little better.