Revisiting the 100 series Master Cylinder diagnosis on 98

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Joined
Jul 17, 2006
Threads
15
Messages
52
Location
Bullfrog,Utah,Lake Powell
I've gone over the most excellent posts, since my 98 UZJ 100, with 260k miles on her started developing a "soft" brake pedal that goes to the floor and will sort of stop the cruiser, but it's going out.

I live in a National Park Service area, so my ability to work on my rig is limited by regulations....However, I am going to attempt to rebuild the master myself, tear it down and replace the MC plunger and seals with the MC repair kit.

My question revolves around diagnosis....I do not have an ABS warning light on, or the "grinding" some have described from the booster motor failing....My pads are good and no recent air in the system, no leaks at relatively new calipers...No visible leaks anywhere.

That being said, is it safe to assume (without having a toyota sst to test pressures) my 260k mile master cylinder has given up the ghost? If so, I'm going to rent a storage shed off of NPS property, where I live, and attempt the master cylinder rebuild myself, using the step by step one of the fine members here posted.

Any additional input and experience or advice on that is much, much appreciated!
 
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Thanks spressomom. I like that advice since you have my 100's twin color wise.:) I know it's a bit of a stretch, but in looking at what else it could be, and showing no other symptoms or culprits at 260k miles, the plunger is my first though. I'm heading toward renting a storage bin off of NPS property and using it as my shop to rebuild the MC myself.
 
I would also include inspecting for stuck caliper piston(s)...but I see you already replaced the calipers with new.
 
Will do. That reminded me to never assume the obvious, and that is a great reminder to follow that rule and verify/eliminate the simple obvious things first.

Great Rig you have spressomom......About to build up mine very similar. Great write up and pics of what you have done, and the build would work well for my desert expeditions here in Southern Utah!
 
Thanks for the compliments. Its been a fun project all along that has taken me to new places, new people & friends and enhanced my skill-sets that would otherwise never occurred.

Funny story from one of our Utah trips a few years ago that landed me at the mechanic's shop on the Hall's Crossing side from where you are working: The front anti-sway bracket that is welded to the frame snapped and...keeping a really long story not so long :D...it was raining and I needed a spot to pull the belly pans and remove the ASB. Never hurts to ask...and we were allowed to use his space. I asked to use his lift but he drew the line there :D

Love all things Nevada and Utah!
 
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