aa7kn

I have a 1991 xj, 5 speed 4.0L motor. As we all know the xj gets super hot under the hood. I have had my XJ for 3 years now and I am about to change the clutch master cylinder for the 3rd time. This can not be normal, is it ? Any others have master cylinder problems for the clutch ? Any one have an idea as to why my XJ is eating them ? They last from 4 to 6 months. I am using Dot3 brake fluid and there are no leaks. Just the peddle goes away and no pressure. Replacing it fix's it for a while. And bleeding does nothing .Please help, and thanks in advance

Cerveja

My friend has Wrangler and has had the same problem. He has had it for about 3 years and has been through 3-4 cylinders now. The first one looks like it was the OEM one and was over the 100,000 mark. The second one lasted a year or so. But then dies as did #3 just a month or two later. The latest one is going on six months now I believe. Fortunately he bought them on line from one of the big 4 Wheel Parts stores, not sure which one, and they have all been warrantied. It's just costing him downtime and labor to swap them out. I think it's luck of the draw. He hasn't found any rhyme or reason that makes the fail and the jeep rarely sees much off-road use.

mentalbreakdown00

Check pedal mount bushings possibly but not probable

freegdr

Don't use the plastic ones theres aluminum ones out there at least for my 89 there was .

freegdr

Like this....http://www.ebay.com/itm/Clutch-Maste...-/300687216232

aa7kn

Thanks for the great feedback, I am getting a master cylinder from the jeep dealer tomorrow and will see how long it lasts. I was wondering about the high temps under the hood....any thoughts on maybe that is the reason the clutch master cylinders are going out so fast ? maybe a high heat issue ? but why doesn't it effect the brake master cylinder ???? any thoughts or comments ?

Lowrange2

I seriously doubt engine temps are hurting the MC.

aa7kn

well guys, I went to the dealer and got an OEM clutch master cylinder, and installed it, real easy except for the nut up under the dash, it sure is hard to get to....anyway, all bled out and it has tons of peddle now and is working like a champ again, just hope this one lasts.....thanks again guys...

freegdr

Betcha that cost a pretty penny hugh...

aa7kn

Well I am in Abu Dhabi in the UAE, and everything is expensive here. The jeep dealer charged about 80 bucks for the master cylinder so the darn thing better last a while. And the 1991 modles and parts are getting harder to get.

ferrel0

Hi, we are having the same problem. Working on customer's 88 cherokee 4.0L. We have replaced the clutch master cylinder 4 times in the last 15 months and just got a call that he needs another one. All of the replacements have been aftermarket. The dealer discontinued them. A fellow shop told us that the new castings for the parts are sometimes being made in worn out dyes causing them to be garbage though they are new). Does anyone have any idea where to get a remanufactured clutch master cylinder for this vehicle? We are getting tired of this happening to our customer. Any help would be greatly appreciated.

cruiser54

If you have never replaced the hose/tube between the master and slave, do it now. The fluid the factory used reacted with the rubber in that line and formed abrasive bits which wiped out the cylinders in short order.

highmileage

I have had four in the past 6 years, the factory one lasted 18yrs. Aside from the one that went out due to the hose blowing apart, the other two seemed to leave me prematurely due to bad rear seals and were leaking onto the fuse box as well. Catch the leaking early or you will be left chasing electrical demons.

freegdr

There now getting ready to do new to me fuse box ...

notop46

I replaced my hose with a braided ss hose and added a bleeder screw at the top of the hose so I do not have to get underneath to bleed it.