3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
The clutch pedal on my 90/325i lost pressure and won't come off the floorboard. I have replaced the clutch slave and master cylinders. All the fittings are snug. The pedal remains on the floorboards. I have tried bleeding the system without success so often that no one in my family is willing to help me bleed the system anymore until I get a second opinion!
Originally posted by 90/325@Aug 27 2004, 02:55 AM The clutch pedal on my 90/325i lost pressure and won't come off the floorboard. I have replaced the clutch slave and master cylinders. All the fittings are snug. The pedal remains on the floorboards. I have tried bleeding the system without success so often that no one in my family is willing to help me bleed the system anymore until I get a second opinion!
check to make sure its not something in the pedal assembly
__________________ Kyle Sutherland
1995 BMW 540i/6: The Calypso Beast Vid 0-70ish 1987 BMW 325es: Face & Butt Lifted/M50tu Swapped*Sold* 1985 VW Scirocco: Too many mods, money pit*Sold* E34 Plate Filler Wanted!
You need a pressure bleeder or a hand held vacuum pump to fix your problem. You have air trapped in the clutch system. You can try pulling the clutch pedal back up to where it is soposed to be and tap on it with your foot really quick like a woodpecker putting a whole in a tree. You don't need to press it very far, just a few MM is enough to work the air out, it may take a few min but this should work if you don't have a pressure bleeder or a vacuum pump. After you give it about 10 quick taps press it to the floor and see if it comes back up, if not give it 10 more and press it to the floor again.
I hooked up a hand vacuum pump to the bleeder valve on the slave. I am now getting fluid through the slave (a dribble at a time - about 2 teaspoons after 20 minutes). Will this process take a while to pull out all the air?
I can use the vacuum pump to bench bleed the master and slave cylinders. That master cylinder is such a pain to get to... The prospect of retrieving and re-installing the slave and master cylinders does not excite me but I am willing to do it if thats what I need to do to get back on the road.
I am going to go back for another round with the vacuum pump before I retrieve both units to bench bleed them. I am hoping the system will fart out an air bubble and give me peddle pressure before then!
What you need to do with the vaccum pump is find a fitting of some sort that will fit over the top of the brake fluid resv. and pull the air out from the top. Make sure the bleeder is closed on the slave cylinder. If you have the Mighty Vac hand pump kit one of suction cup looking adapters will fit the brake fluid resv. When pulling the air out from the top make sure the pedal is up where it is soposed to be otherwise the air won't come out. The way I do this at work is i pump it up to the max vaccum it will pull and let it sit for a few seconds, you should see air bubbles come out into the fluid resv. Once the air bubbles have slowed or stopped comming out release the vaccum and see if the pedal works. If it doesn't pull the pedal back up to where it is soposed to be and apply vaccum to the fluid resv again.
Thanks for the tip AJ. All of the manuals I have read approach this issue from the slave cylinder side of the system. Sometimes you have to think outside the box to find your solutions....
I was lucky enough to purchase the "Mighty Vac" unit. The suction cup unit you descride just fits inside the reservoir. After a few pumps the gauge still measures zero. I can't seem to build any pressure? I tried to cover the edges to get a better seal with no luck. After about 6 pumps the whole set up plops into the reservoir.
I gave the suction cup set up another try. This time I flattened it out like a pancake to cover more surface area (from the top instead of inside the neck where it plops in when the pressure builds up).
I have been able to build the pressure between 10 and 15.
The peddle is still on the floorboards.
I will give this a shot a few more times.
Wish me luck....
Glad I could help, and stick with it. 10 to 15 inches of vaccum should be enough to pull the air out. As long as you keep getting air out of the system thats all that matters. Since it sounds like there is a lot of air traped in your system it may take a little longer than normal. Another thing that helps is to fill the brake fluid resv to the max line this will keep physical pressure on the air in the system to help force it out when your apply vaccum. You can also hold onto the suction cup thing with one hand to keep it from falling in, this will allow you to pull more vaccum just make sure you don't get any brake fluid in the hand pump. If for some reason you do get fluid in the pump take the gauge and rubber cap off that is in front of the gauge and give it a few pumps this should clear out the fluid inside.
Glad I could help. I've been working on all sorts of different types of cars since i was 14 (I will be 25 in a couple of months) so I've learned a lot of differnt tricks that you won't find in any shop manual.
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