Clutch master cylinder broken for the third time


Sam

New Member
Joined
Jun 28, 2020
Messages
2
Location
Virginia Beach
Hey I just wanted to know if this has happened to other people, and if so how did they fix the issue. For the third time now, my YJ's clutch pedal has given out completely while driving, just dangling freely. The first two times I had it towed to a repair shop where they replaced the master cylinder. Since this is recurring within a couple years, I towed it home instead to see if I can figure out why this keeps happening. Anyone else have any info about this? Anything would be greatly appreciated.
 
OP
S

Sam

New Member
Joined
Jun 28, 2020
Messages
2
Location
Virginia Beach
I've never seen that happen. What part is breaking? The shaft or the bolt that goes through the pedal?
It seems to be the O ring around the plunger thats driving the master cylinder that is failing. No pressure is being applied to the system when the clutch is pushed. I'm getting a new master and slave system in a few days so hopefully all will be fine aftee that. Just hope i wont have to do this for a fourth time in a year.
 

undershaft

New Member
Joined
Sep 13, 2021
Messages
1
Location
Charleston
It seems to be the O ring around the plunger thats driving the master cylinder that is failing. No pressure is being applied to the system when the clutch is pushed. I'm getting a new master and slave system in a few days so hopefully all will be fine aftee that. Just hope i wont have to do this for a fourth time in a year.
I'm having the same problem. On my third one. What was the solution?
 

T-Rex Jeepster

The Unoffendable
Supporting Member
Joined
Sep 13, 2021
Messages
88
Location
Middle Tennessee
It seems to be the O ring around the plunger thats driving the master cylinder that is failing. No pressure is being applied to the system when the clutch is pushed. I'm getting a new master and slave system in a few days so hopefully all will be fine aftee that. Just hope i wont have to do this for a fourth time in a year.

This is what I was going to suggest..........
 

Flyer58

YJ Enthusiast
Joined
Apr 12, 2020
Messages
481
Location
Magnolia, Texas
I have not had mine apart yet to see the parts or how it works but if it's always the same o-ring then I suspect it's more likely the push shaft has a nick in it and is cutting the rubber ring.
 

T-Rex Jeepster

The Unoffendable
Supporting Member
Joined
Sep 13, 2021
Messages
88
Location
Middle Tennessee
I have not had mine apart yet to see the parts or how it works but if it's always the same o-ring then I suspect it's more likely the push shaft has a nick in it and is cutting the rubber ring.
When the fluid goes bad and moisture collects in the system...The surfaces that the O-ring slides on become pitted with rust and destroy the sealing ability of the ring, Hence Limp pedal.....I'd replace with an entire kit. The lines come attached to the slave cylinder
on the kit I used.
 
  • Like
Reactions: Flyer58

Flyer58

YJ Enthusiast
Joined
Apr 12, 2020
Messages
481
Location
Magnolia, Texas
When the fluid goes bad and moisture collects in the system...The surfaces that the O-ring slides on become pitted with rust and destroy the sealing ability of the ring, Hence Limp pedal.....I'd replace with an entire kit. The lines come attached to the slave cylinder
on the kit I used.
Yeah I change my fluid every three years or so. Many owners never change the fluid.
 

Moellertime

New Member
Joined
Nov 20, 2021
Messages
3
Location
Fort Worth, TX
I’ve replaced the whole system twice and it just failed again. Was using the advance auto parts kit now trying oreilly (Napa doesn’t carry it anymore). Anyone figure out what causes this to fail?
 

machoheadgames

Certified YJ Researcher
Supporting Member
Joined
May 19, 2020
Messages
950
Location
Dallas, TX
I’ve replaced the whole system twice and it just failed again. Was using the advance auto parts kit now trying oreilly (Napa doesn’t carry it anymore). Anyone figure out what causes this to fail?
Oreilly's kit was awful for me, replaced 4 or 5 of them in 4 years. Not sure what advance auto sells, have a pic?

The "why" for why they fail is cheap manufacturing of parts. It is unfortunate.
 

Moellertime

New Member
Joined
Nov 20, 2021
Messages
3
Location
Fort Worth, TX
So I’ve done some more research and apparently the LuK CRS032 is the kit you want to get that fits the 94-95 YJ. Unfortunately I can’t seem to find that one anywhere. Anybody know another brand that doesn’t fail all the time?
 

machoheadgames

Certified YJ Researcher
Supporting Member
Joined
May 19, 2020
Messages
950
Location
Dallas, TX
So I’ve done some more research and apparently the LuK CRS032 is the kit you want to get that fits the 94-95 YJ. Unfortunately I can’t seem to find that one anywhere. Anybody know another brand that doesn’t fail all the time?
the luk and the other options on RockAuto have all looked identical to me. That's why i want a pic of what failed for you. I want to see if you were running something similar to the oreilly crap I had, or if you have something similar to the Luk.
 

Moellertime

New Member
Joined
Nov 20, 2021
Messages
3
Location
Fort Worth, TX
Hey I just wanted to know if this has happened to other people, and if so how did they fix the issue. For the third time now, my YJ's clutch pedal has given out completely while driving, just dangling freely. The first two times I had it towed to a repair shop where they replaced the master cylinder. Since this is recurring within a couple years, I towed it home instead to see if I can figure out why this keeps happening. Anyone else have any info about this? Anything would be greatly appreciated.
the luk and the other options on RockAuto have all looked identical to me. That's why i want a pic of what failed for you. I want to see if you were running something similar to the oreilly crap I had, or if you have something similar to the Luk.
Not with the Jeep right now but the last time it failed at where the piston connects to the master, it would just move freely and not compress the fluid. Pretty sure they were the oreilly type one
 

machoheadgames

Certified YJ Researcher
Supporting Member
Joined
May 19, 2020
Messages
950
Location
Dallas, TX
Not with the Jeep right now but the last time it failed at where the piston connects to the master, it would just move freely and not compress the fluid. Pretty sure they were the oreilly type one
As soon as you get a chance, post a pic of the master. Oreilly types are usually cast iron/metal. The better ones are usually a mix of plastic and other stuff.