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Clutch hard to push after 1/2 throw, blowing Master Cylinders

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  #1  
Old 09-10-2013, 10:52 PM
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Default Clutch hard to push after 1/2 throw, blowing Master Cylinders

I am having a baffling recurring issue with my new-to-me truck. Hoping someone might have an idea or wisdom to throw at this issue.

Back story:
Bought truck un-driveable
Diagnosis after towing home was a grenaded DMF.

Purchased and installed the following:
Single Mass Flywheel BECK/ARNLEY 0656031
SMF Clutch Kit LUK 04163 (04-163)
Clutch Fork RHINOPAC / WORLD CAR CF126
Clutch Master/Slave and Line DORMAN CC649028
Pivot Ball
And also the housing the release bearing rides on, as this was destroyed when the DMF grenaded.


After fixing issues from previous owner:
Put this all back together and truck ran great. However after 3-400 miles the clutch master cylinder blew out. I didn't check exactly where on this first one.
Ordered the same assembly from Rockauto and installed it, truck again ran great but now I'm self conscious and notice that the pedal is much harder to push once it gets about 1/2 of the way down. The fork is in-fact moving before it reaches 1/2, as I confirmed now that I have the transmission out and look while I push the clutch in.

After another 500 miles or so the new clutch master cylinder blows out at the bottom and I am again crash-boxing the truck home with no clutch.

I had a friend push the clutch while I looked in from the bottom of the bell housing peek-hole and could see stuff working. There is what appears to be sufficient grease on the pivot ball. I can hear a sound when it reaches past 1/2 pedal travel like there is possibly some excess friction going on.


This Week
I have a new Master cylinder again so the hydraulics are again working, but I need to find the root cause of them failing.

I took out the transmission thinking it was lack of lubricant between the release bearing and what it slides along (transmission housing). However without the transmission installed I push the clutch in and there is definitely a hard spot after about 1/2 pedal travel.


What I would love to hear:
Has anyone had an issue like this before? Was there a solution?

Does your clutch feel the same throughout the pedal travel? With exception of the free play at the top of course.

Any comments or help would be much appreciated!

--Christopher
 
  #2  
Old 09-12-2013, 11:24 PM
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How about this, does the clutch pedal in your truck go all the way down with relatively the same force or does it change at a certain point?

Thanks!

---AutoMerged DoublePost---

A friend of mine came by tonight to take a look again with the transmission removed. He pointed out that the clutch fork was coming up off the pivot ball at the same time as the pedal was getting harder to push.

I suspect, though I'm not going to take it all out to measure, that the Single Mass Flywheel and pressure plate assembly is not as deep as the original dual mass flywheel so the clutch fork is making a longer trek to "full travel". This in addition to a slightly different design of clutch fork is causing it to pivot on the bell housing.

We are going to modify the clutch fork and see if we can get it put back together without it touching the bell housing.
 

Last edited by Fourthbean; 09-12-2013 at 11:24 PM. Reason: Automerged Doublepost
  #3  
Old 09-13-2013, 05:07 PM
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I have a new Master cylinder again so the hydraulics are again working, but I need to find the root cause of them failing.
Dorman products are crap my freind as are bwd part and the stuff they sell at the zone these parts are inferior to the AC/DELCO parts either AC or Napa
 
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