Clutch Replaced - Continued Soft Pedal

[leroge]

Just had the clutch master cylinder, throwout bearing, pressure plate replaced on my '93 Wrangler ( 4.0 L ). The master cylinder was replaced by a shop different from the one that replaced the throw out bearing and pressure plate. A couple of days out of the shop after the throw out bearing was replaced, the clutch pedal got softer by the day until one morning the pedal went to the floor and I couldn't shift at all. Seemed that as the pedal got softer, it would 'come back' somewhat after the engine was heated up. Eventually, after four days, not even heating up the engine gave me enough clutch.

Seeing that I was in the middle of Michigan and the repairs were made in Chicago, I thought I'd simply bleed the clutch. After bleeding, clutch works fine - nice hard clutch pedal! As I bled the DOT 3, I did notice air in the line.

So, what happened? I spoke with the shop that replaced the throw out bearing and he blamed the master cylinder ( as you might suspect, make it someone else's problem! ). I figured that might be plausible since the reservoir of the master cylinder never lowered in DOT 3 level as I continued to lose clutch pedal over a number of days. For that matter, I noticed a slight flow ( very slight ) on the bottom of the new master cylinder each day...as if it was being blown out from under the reservoir cap - even though the cap was tightly turned.

What do you think? Note that the clutch is working just fine since I bled the system!! Would a poorly bled hydraulic line cause a slow softening of the clutch pedal? Why would heating the engine result in a less soft pedal?

[4x4grey88]

Originally Posted by leroge

Just had the clutch master cylinder, throwout bearing, pressure plate replaced on my '93 Wrangler ( 4.0 L ). The master cylinder was replaced by a shop different from the one that replaced the throw out bearing and pressure plate. A couple of days out of the shop after the throw out bearing was replaced, the clutch pedal got softer by the day until one morning the pedal went to the floor and I couldn't shift at all. Seemed that as the pedal got softer, it would 'come back' somewhat after the engine was heated up. Eventually, after four days, not even heating up the engine gave me enough clutch.

Seeing that I was in the middle of Michigan and the repairs were made in Chicago, I thought I'd simply bleed the clutch. After bleeding, clutch works fine - nice hard clutch pedal! As I bled the DOT 3, I did notice air in the line.

So, what happened? I spoke with the shop that replaced the throw out bearing and he blamed the master cylinder ( as you might suspect, make it someone else's problem! ). I figured that might be plausible since the reservoir of the master cylinder never lowered in DOT 3 level as I continued to lose clutch pedal over a number of days. For that matter, I noticed a slight flow ( very slight ) on the bottom of the new master cylinder each day...as if it was being blown out from under the reservoir cap - even though the cap was tightly turned.

What do you think? Note that the clutch is working just fine since I bled the system!! Would a poorly bled hydraulic line cause a slow softening of the clutch pedal? Why would heating the engine result in a less soft pedal?

Normally when you get the clutch replaced they replace the throw out bearing from the kit. If I had repairs made in a shop I would take it back to them to make it right. Don't just take someones word for something over the phone. No-one can make that call by just seeing a soft clutch. Someone will have to re-open the clutch assy and look to see what is wrong with it PERIOD !!!!

Never tell someone that someone else worked on it after they did. If it is warrantied then have them fix it (even if it take a long drive).

[rhandwor]

Normally when you pull the transmission the slave cylinder should be replaced.
I think the slave cylinder is leaking. I don't remember if you have to pull the clutch to replace this one but you should be aware of this.

[oljeeptek]

You had air in the system, the question is where it came from. If you didn't replace the slave cyl, and it holds the solid pedal don't fret it. It'll be fine. You generally replace the slave when it's open because it's a P.I.A. to do it again.

If you lose the pedal again your sucking in air somewhere. It could easily be pulling it past the cylinder seals or it could have been even around the threads of the hose or even the bleeder. I've even seen DOT 5 brake fluid get installed as it is compressible because it is silicone based and yields a mushier pedal. Bleeding it out solved that issue on more than one unit.