Clutch slip

[Mike Norton 2]

My 01 ST has 64K and the clutch has slipped on me twice the past 3 months.

I had it towed to the dealer the first time and they said it was time to replace it but wanted $1300.

I got another opinion and the mechanic tells me nothing is wrong with it now (since he drove it around town w/o a problem) so I drove it another 3 months and it happening again. (clutch pedal is soft and won't go into any gear)

But after pumping the pedal it seems to come back and work fine.

Any suggestions what this problem could be? Any help would be appreciated.

 

[Andy G]

Sounds like your slave cylinder on the clutch is going out.



$1300, I don't think so.......



I would be willing to wager you can have a new cylinder, as well as clutch put in for less than $800. The clutch may not be bad, but if you have to go in and do the cylinder anyways, may as well get the clutch too..

 

[Brad Bottoms]

I just had similar problems on mine, but with only 24k miles. Same symptoms as you just all the time! Either your slave cylinder or master cylinder is going out if it is intermittent. I just had my slave cylinder replaced and it ran $600. $450 of this was labor and $150 was parts/shop supplies. There shouldn't be any other labor involved with a clutch other then resurfacing the flywheel. So $800 should get it at an independent shop for a cltuch and slave cylinder.



Depending on the local labor rates, your price may vary some, so figure 5-6 hours most likely (4x4) at whatever labor rate you get.

 

[Fudged Undies]

Two possibilities.. Slave cylinder is going or your master cylinder is letting air into the system in which case it's going too. I've had a variable clutch pedal pretty much since day one. Went back to the dealer three different times (for different reasons) each time it was reported to be "within specs." Unfortunately, "within specs" doesn't mean it's correct. When you say the clutch slipped, can you expand a bit? Did the rpms race up beyond the rate at which the trac was accelerating? The slipping would lead me to the slave but the pedal makes me think master. If you have any other details or odd happenings please post.

 

[Rodger Tellefson]

We have a '01 Job 2 w/ manual tranny, and I concur with both Brad & Spaceman. Have a good shop take a close look at both the slave & master culinders.

 

[Andy G]

I would absolutely have both cylinders checked. But from my experience, the slave always seems to have a much shorter life than the master. And since a dealer had already quoted $1300, I had assumed they checked the master already, since that is more like a $200 - $300 fix. You have to pull a tranny to get to a slave, but the master is a much easier job, since it is typically located on the firewall.



I don't know where exactly the master is on the ST, but on my old Jeep Cherokee, if your master was leaking, you could find fluid on the inside of the firewall in the area of the gas/brake/clutch pedals. This was because the master was inside the cab, right above the clutch pedal.



Slaves take way more abuse, vibration and pollution than the master does. And for that reason, the master will typically (but, not always) outlive a slave. My Cherokee had the slave replaced at 150K, I sold it at 220K with the original master in there. The guy I sold it to, just replaced the master at almost 250K.



But, STs are not Jeep Cherokees, and perhaps the situation is completely different.

 

[Fudged Undies]

The master is on the driverside fender, within a foot of the fire wall. It's relatively small similar to a 6-8 oz cup. I would think if the slave were leaking there should be some fluid residue around the tranny and on the ground wherever you park for extended periods of time. I have heard the master is capable of leaking air into the system though I don't know if it would leak fluid at the same time. I have never owned an automatic and have yet to see a faulty master cylinder, my last vehicle making it to 200K miles.

 

[Mike Norton 2]

Thanks for the info. There is no leaking on or around where I park but I will have it looked at anyways.



Thanks again

 

[Richard L]

Surprise! clutch slave cylinders rarely leak when parked! So you won't necessarily find a puddle of fluid under your truck.



I'm convinced it is your clutch slave cylinder. It may be leaking but it also may also have a corroded cylinder bore and that is causeing some binding and creates the erratic operation of the clutch. Your clutch can be slipping because the clutch slave cylinder is sticking when attempting to engage the clutch and not allowing the full pressure to push the clutch disc to the flywheel.



Difficulty in shifting or getting the transmission is caused by a fluid leak and/or air in the clutch slave cylinder somewhere in the system, but usually in the slave cylinder. When you press in the clutch pedal to shift into gear, the air or lack of fluid pressure does not allow the clutch to fully disengaging and is like trying to shift with no clutch. If you pump the clutch peddal a few times and it shifts easier, you have a fluid leak in the clutch slave cylinder system.



If you crawl under your vehicle you will probably see evidence of the leaking slave cylinder because there will be and oily residue on the undersided of the vehicle starting at the clutch and back.



...Rich