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Old 08-01-2015   #1
JohnnyRockit
 
Join Date: May 2015
Location: Dallas, TX
Posts: 17
Default Changed my clutch slave cylinder today.

As I've posted previously, my 91 has a clutch slipping issue, especially with the power key on (which it always is). From a dead start it won't break the tires loose, the clutch can't grab.

So, today I installed a NAPA slave cylinder that I bought a few weeks ago. The whole job took about 30-40 minutes, not a big deal. Prior to installation, I put the slave in a vise and compressed the rod all the way in, then I poured fluid into the hole where the line goes as I released the pressure on the rod. I was hoping this would alleviate some of the bleeding...surprisingly, I did not have to bleed the clutch at all. I think I gave the pedal about 30 pumps, started the car and it easily went into first gear, yay!

Unfortunately, the slip is not cured, but it is improved quite a bit. Previously, if I accelerated hard at about 40 mph in 4th gear, the revs would jump up about 500-700 rpm and then the clutch would slowly grab. Now it just jumps about 300 rpm and comes down much quicker. Although it still won't break the tires loose from a standstill (not a big fan of treating my car like that anyway). I did hear the tires breaking loose a bit when I accelerated from about 20 mph through first gear.

So, while I wish I could have solved my problem, at least I have a new slave cylinder and fluid installed with better clutch performance. And maybe bought a little more time on this clutch until I either have time to put in a new one or have it done (not looking forward to that project).

Johnny
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Old 08-02-2015   #2
RussMcB
 
Join Date: Jan 2015
Location: Marietta, GA USA
Posts: 1,160
Default Re: Changed my clutch slave cylinder today.

Sounds like good progress, at least.

While under my car recently I noticed my clutch slave cylinder. It looks original and old. I wondered if it might be a good idea to change it. I'm glad to hear it's not a big job.

I also noticed the bleed valve was on the bottom, and wondered if it should be bench bled, and then maybe bled again after the hose is attached, but with the slave cylinder loose so it could be moved around by hand to get the bubbles near the bleed valve.

I suppose you are thinking that a new clutch plate is needed. That reminds me of something I saw while watching an IMSA sports car race on TV a long time ago. A prototype team's clutch was slipping, so they brought the car into the pits and poured a can of Coke (or Pepsi) into the bell housing. I can't remember if it helped or not, but that's something I'll probably never forget. Whooda thought?

Good luck with your next steps.
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Old 08-02-2015   #3
JohnnyRockit
 
Join Date: May 2015
Location: Dallas, TX
Posts: 17
Default Re: Changed my clutch slave cylinder today.

Mine was a little crusty looking as well, that's why I figured it was time for a new one.
Just bench fill the slave completely prior to installation per my prior post. I completely filled it with fluid and reinserted the little plastic plug over the hole for the fitting. Then, while under the car, removed the plug and installed the line. I was worried that since I lost all the fluid in the line and reservoir that I would have issues with air in the line. That is why I pumped the pedal about 30 times after refilling the master reservoir. Check your fluid level once more after that step.

I'm still having a hard time believing that my clutch is bad, since the car only has 23K miles on it. Prior owner must've ridden the clutch, or maybe there is another issue...I'm still researching possibilities!

Johnny
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Old 08-03-2015   #4
WARP TEN
 
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Join Date: Apr 2007
Location: Lake Bluff, IL
Posts: 2,031
Default Re: Changed my clutch slave cylinder today.

Quote:
Originally Posted by JohnnyRockit View Post
......I'm still having a hard time believing that my clutch is bad, since the car only has 23K miles on it. Prior owner must've ridden the clutch, or maybe there is another issue...I'm still researching possibilities! Johnny
It happens. When I got my '95 in 2012 it had 21,000 miles on it. Clutch seemed OK. When about a year later Marc Haibeck had the engine out for the 510 package work he discovered--much to our surprise--that the clutch disc was completely worn away and needed replacement. The car otherwise showed no signs of excessive wear or abuse and the mileage is accurate. The long time previous owner (1999-2012) lived in a somewhat hilly area of Southern California and we assume that he simply would ride the clutch on hills. No other real explanation as I do not believe he raced it much if at all. --Bob
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