Cannot figure out this Montero clutch problem

[Tnora]

Hello,
I am the original owner of my 1991 Mits Montero 5 spd. It has 103,000 miles on it. When I drive up grades where I'm shifting between 3rd and 4th to maintain decent 40-50mph speed, my clutch goes soft and I have to pull it back up with my toes and quick pump it to get it firm again so I can shift gears. I checked the clutch fluid reservoir and it is full. No signs of leaks anywhere. Drained and bleed and put new dot 3 fluid in and same problem occurs. Clutch is firm and works perfect after grade flattens out and engine isn't working so hard. I noticed slave unit is inches next to exhaust manifold but heat shields are intact. All my clutch hardware is original. Any suggestions regarding this strang phenomenon?

 

[JohnnyBfromPeoria]

Try replacing the master and slave cylinders. Rock Auto has them both for under $40, at least for the 85 I was looking at over the weekend.

John B.

 

[Tnora]

Thanks John. Rock auto price is good. I've never done a master or slave replacement before. I did bleed the system last summer. I've been quoted labor prices of $240 and higher so I was thinking of doing it myself. Is it a simple exchange out the old part for the new one or are there some quirky steps involved?

 

[JohnnyBfromPeoria]

You can down load the factory service manual at www.mitsubishilinks.net and all the procedures are there. The slave is a simple replacement, then bleed. The master cylinder is a little more in-depth, but not really hard. You may have to bench bleed the master, undo the pedal linkage, install and bleed the system, but it doesn't look very hard. I've never done one of those, though.

John B.

 

[Tnora]

Put the new slave and master clutch cylinder on last weekend. It was very easy with a friends helpful hand. No leaks and shifts nice. This weekend I will put it to the altitude test and head up to 6-7k feet in the sierras and see if my clutch pedal stays firm and shifts like it did in 1991. BTW John, the factory service Mits link you had in your last post, doesn't exist anymore.

 

[Tnora]

Clutch works great and no problems with new slave cylinder and master cylinder. Took the Montero over Sierra Nevada Kaiser pass, 9200', to lake Thomas Edison. Clutch pedal stayed firm in high altitude driving. Also took it to courtright reservoir, another high altitude lake, with no problems. Both trips while towing a 14' fishing boat. Problem solved.

 

[plh]

BTW John, the factory service Mits link you had in your last post, doesn't exist anymore.

www.mitsubishilinks.com