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1990 Jeep Comanche Question: slave cylinder problems

 

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Visitor, 4.0L 6 Cylinder, Boaz, AL, March 18, 2010, 17:11

I have a 1988 Jeep Comanche that keeps blowing out slave cylinders. Just replace the slave and master cylinder. Seemed to fix it until I drove it for a day and it blew the slave cylinder out again. Any suggestions?

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  • Answer #1

    Visitor, March 28, 2010, 14:00

    Replace the flywheel when the flywheel wears too thin the slave cylinder over extends and the seal becomes damaged. I replace my flywheel and have not had that problem since the flywheel was replaced. An alternative is to get the transmission with external slave cylinder and dump the Peugot POS tranny. 1989 and up don't use the Peugot POS tranny.

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  • Answer #2

    Visitor, August 10, 2010, 13:59

    The answer to this problem lies in the distance the pressure plate diaphram (fingers) extends behind the pressure plate. There are 2 different pressure plates. One says in the calalog "extended diaphram". After you torque down the pressure plate the diaphram must extend beyond the rear surface of the pressure plate housing in order to have sufficient travel for the slave to release the clutch. When I had the wrong pressure plate I corrected the problem with .005" shims between the pressure plate and flywheel at the bolts. Use trial and error it may take up to .010 in shims however as the clutch plate wears the diaphram extends further so don't put too much shim so that the diaphram will bottom out on the housing or have no free travel in clutch pedal. With a new clutch plate, diaphram should extend just behind the housing. If the diaphram is recessed into the housing there will not be enough travel in the slave and the seal will be damaged and clutch not release.

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    west4967, September 02, 2012, 11:40
     Rookie

    i have the same problem. i blew out two clave cyilenders. i ended up shiming mine 0.010 now the slave cyilneder is working but still not giving me enough to engage the clutch and i dont realyy want to shim it anymore. its an 88 comanche with the 4.0. i cant find the extended presure plate through any of the parts places here. any idea where i can find one?

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  • Answer #3

    moosenman July 19, 2013, 14:52
     Rookie

    hi my name is ken i have a 89 doing the same thing,did it 3 times after all that the internal slave and throw out bearing enve from luk is 1/4 inch shorter when expanded than the one from crown big issue.took me months to find out,the outhers would only last a couple of days because they were over extending themselfs.

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