2003 Chevy Cavalier My clutch isn't holding pressure.

Tiny
FEZ
  • MEMBER
  • 2003 CHEVROLET CAVALIER
  • 4 CYL
  • FWD
  • MANUAL
  • 81,000 MILES
I have just replaced my clutch master cylinder, bled the lines of air, and looked for leaks in the lines and seals, but the lines still aren't holding pressure. When I bleed the lines the clutch goes back to how it should feel (slight pressure until I hit the sweet spot, and then about 1.5" of travel to the floor. It does great for about a block or two and then the clutch pedal isn't returning and the gears are difficult to shift into. Normally the shifter just goes into the respective gears with little to no effort but when this occurs the shifter then needs to be forced (as I slap my own hand for doing this) into but not out of gear. I can feel as the clutch pedal slowly loses pressure from the master cylinder for the first 4-5 times I push it in, but after that it just instantly goes out. Also, I noticed as the clutch is pumped to bleed the lines, there is a spurt of fluid from the reservoir valve back into the reservoir so forcefully that it shoots out of it like a fountain about 2-3 inches. Is this just a bad master cylinder or is there a mechnism that should stop this from happening? I've read on forums that there is a seal in the master cylinder that is being bypassed when this happens, but when I cracked open the old one (pulled the piston out of the master) it appeared as follows: the fluid enters from in MC fluid intake valve (outside of the piston wall) and then goes into the piston wall and out to the line leading to the slave cylinder. I saw no remnents of a seal inside of the MC. Unless the seal is part of the piston and is only supposed to work one way, in which case I'm lost on that one.

So to recap: remove old MC, check; attach new MC to SC line, check; install new MC, check; attach MC reservoir tank, check; bleed lines, check; look for leaks along all lines, connections, and external seals, check; original problem still exists, check :( What should my next course of action be?
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Wednesday, April 22nd, 2009 AT 11:41 PM

7 Replies

Tiny
M_H_RITZEL
  • EXPERT
It sounds like the slave cylinder is not holding pressure. If you get it up in the air have someone press on clutch pedal and look at the movement of the slave cylinder. When you have bled the cylinder before it fills the slave cylinder and after a few times of using the clutch the cylinder looses pressure.
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Thursday, April 23rd, 2009 AT 8:54 AM
Tiny
FEZ
  • MEMBER
Well, the fluid running back into the reservoir from the MC is where I am now thinking it was just a bad seal on the new MC. The seal could have dry rotted from sitting on a warehouse shelf for a couple of years before going to the store. After talking to several mechanic friends they all seem to agree. The slave cylinder on this car is on top of the transmission so the lift is not needed. The slave cylinder was checked by one of these friends since my original post and is fine. Thanks for the help and concern, just got a little confused before posting and tried to back it out before it posted. I am trying another MC today and if this same problem occurs I will have the guys at the store replace the seal, as I am not waiting two more days for a replacement part again.
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Friday, April 24th, 2009 AT 5:18 AM
Tiny
M_H_RITZEL
  • EXPERT
It is possible that it could be the MC, I have seen new ones that were defective even brand new ones.
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Friday, April 24th, 2009 AT 8:11 AM
Tiny
FEZ
  • MEMBER
Actually, it got really bad after the new MC got put in. It ran fine for about 5-6 hrs and then the save went out. I thought that the SC was leaking just inside the trans. Well, I was part right. The SC on these is actually in two parts. The first part in the chain is the external SC that runs about $25 at the part store. Well, the bad side was the part inside the trans. It's actually the concentric actuator SC and throwout bearing assembly, all one part! That part was also about $330 and had to drop the trans to get to it! I was upset. I had never heard of this before! Who's dumb@$$ idea was it to do away with the clutch fork and put the important part of the SC inside the trans! It took myself, my wife's stepfather (ex-motor pool mechanic) and my dad (mechanic of 46 years!) Almost 12 hrs just to drop the transmission. I was in luck that my dad had all of the specialty tools needed for this job. The only ways to get the transmission out was to either unbolt the front end frame, or pull it from the top. As none of us wanted to unhook all that was needed to pull from the top, we went from the bottom. I've got to say, if this is the best they can design a car, then they need a few new designers. The only part of the frame that was in the way, was a small piece that juts off of the front driver side, that was hooked to, or supporting NOTHING! The other side of it was hooked to the transmission support, but that side had no structural need other than to get in the way of dropping the transmission without unbolting the entire front end frame! Needless to say, we only dropped it far enough to get to the SC/Throwout bearing/retarded part. The only reason these cars are designed the way they are now, is to make part stores and specialty shops money! Granted these people need to eat too, but for those that just don't have the money for 18hrs labor ($75/hr) and $500 in parts (you do the math and see if you could afford that in one go), that's $1850 that I couldn't get extra in 2 months, and can't go that long without a car! If I can, I will try to get a picture the frame to post. This is getting ridiculous! Anyway, thanks for all of the help, and the preminition early on about the SC (it didn't go out until the ne MC practically blew it apart in there), and wish you the best of luck.
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Tuesday, April 28th, 2009 AT 2:53 PM
Tiny
M_H_RITZEL
  • EXPERT
With modern cars everything they put in is compact and try to save room. The more complicated cars get it is a wonder that anyone car anymore. I like the old cars like the one I am working on a 1962 ford and its simple to work on. I understand the agrivation of working on new cars. It's modern technology.
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Thursday, May 7th, 2009 AT 9:30 AM
Tiny
RPETERS
  • MEMBER
I have the exact same problem to the T.
Currently I have a new MC and new line and it is still leaking fluid, from what seems to be that hole in the bottom of the tranny that you can see the gears. Any other advice before I take on this task?
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Sunday, October 18th, 2009 AT 2:21 PM
Tiny
M_H_RITZEL
  • EXPERT
If leaking by transmisssion then check the slave cylinder for leaks. Check the fittings for leaks.
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Wednesday, October 28th, 2009 AT 12:29 PM

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