Master/slave/clutch problem

...You haven't said if you have ever replaced the original Master Cyl.? You have fluid leaking past the Piston at a 'Spot' in the Masters' Bore! NO Leaks outside, just inside! If you do replace the Master; replace the Slave, Also! It's just the correct way to do things. Hall Pantera use to give a discount if you purchased Both at once. Good-Luck!...

What it can be is the diaphram in the clutch pressure plate.
That is ... if it is a diaphram stlye clutch plate ( lots of little fingers)
What happens is the diaphram colapses, and no longer sits out ready for the fork to push it.
What happens then is the diaphram doesn't release the clutch plate when pressed.
I have seen it happen many, many times.
Also you can check that it is not the clutch or slave cylinder, watch the slave and get a friend to press the clutch, if it travels all the way it works fine.
if you can move the clutch arm ( on the top of the box ) with your hand it will be the fork or the pressure plate ( clutch).
sorry for the bad news !
good luck.

Jack, I haven't replaced the master, or clutch. I have owned the car for less than a year and I'm not sure when that work was done in the past.

The person that listed my car for sale on this forum in 2002 listed it as having a new centerforce clutch and SS long throw slave. No mention of the master.

R.

UPDATE:

I went to the mechanic, asked to see the master cylinder, and noticed the fluid level was low. Filling it didn't fix the problem, but it made me crawl under the dash as look for a leak...and I found one. The boot was all wet.

So I am ordering a new master (and maybe slave, but it only has a few thousand miles on it).

New info: when I start the car in neutral it sounds normal. When I press the clutch pedal it makes a screaching/rattling noise for a second or two. The mechanic says that is what he based his diagnosis on, and that it is the clutch or throw out bearing. That sort of makes sense, right?

When I press the clutch pedal it disengages the clutch now. Maybe because I added fluid, maybe because the problem is intermittent, who knows.

R.

Here is what I think based on the verbal description:

1) As you rightly point out the clutch Master boot (under dash) should not be wet. To me this indicates a failure of the Master.

2) A Clutch throw-out bearing could also be a problem. If the bearing has failed the tolerances could be out for engaging and disengaging the clutch. A quick way to check is to idle the car in neutral. If you hear a rattling sound, or a sound like the engine is detonating (can't be at idle) coming from the clutch area (belhousing), then it is probably your thow-out bearing rattling around. It will need to be changed.

3) I wonder whether the screaching could be caused from a seized throw-out bearing. Sounds plausible as well.

B.G.

Another update:

Looks like I had two problems. The master was leaking (soft pedal) and the throwout bearing was toast (noise in the bellhousing).

The master is being installed and the new throwout bearing is on the way.

Should I replace the clutch as well? The mechanic says the clutch looks good. Supposedly the clutch only has about 5000 miles on it, so maybe the previous owner changed the clutch without changing the throwout bearing?

R.

quote:

Originally posted by RobertVegas:
Should I replace the clutch as well? The mechanic says the clutch looks good.

For the extra couple hundred bucks it would cost, I would change the clutch and pressure plate too, just to know it was all fresh and installed at the same time. You wouldn't have to worry about it for a good long time at that point. (Heck, I might even take the opportunity to go with an aluminum flywheel while it's all apart.) There's nothing worse than having to go back in there again to change something else, when you were just in there! Oh, and don't forget to check and/or replace the pilot bushing.

Michael

I agree change the clutch,pressure plate, & pilot bearing while it's all apart. Oh don't forget to check the ZF and make sure it's safety wired and have the flywheel surfaced.

LOL... it never seems to end

I am installing a new master cylinder, clutch, pressure plate, throwout bearing and pilot bushing. I will look into getting the flywheel surfaced.

Oh yeah, and when they put the car on the lift they noticed one of the rear wheels had some play in it...so I am having new wheel bearings installed as well.

Did one of you comment that "it never ends"?

Man, this car was already sweet. Now, with all the upgrades and fixes, I feel like it is really sorted out. I am actually glad when something acts up, because I fix it and add it to the "new parts" list.

R.

quote:

Oh yeah, and when they put the car on the lift they noticed one of the rear wheels had some play in it...so I am having new wheel bearings installed as well.

FWIW, Robert, rear wheel bearings are seldom at fault. Apparently for ease of production, DeTomaso sized the rear outer stub axles too small in diameter for an adequate press fit into ball bearings. The outcome of feeding 300+ horsepower thru the rear tires causes the axles to move a little, and since bearing races are MUCH harder than the mild-steel stub-axles, the axles wear. I've seen as much as 0.030"worn into some, and it only takes 0.002" to make a rear tire wobble. So be very sure your repair shop understands what they're dealing with or the problem will return almost instantly. The press-fit needed is only 0.0005-0.0008" and yes- the decimals are correct.
There are several 'fixes': billet 4130-steel axles are sized properly for the above press fit, and stock worn axles can be welded up, then hard-faced or hard-chrome plated to fill in wear and produce the proper press fit. Finally, some convert the rear wheel bearings to tapered roller bearings, thinking it's a bearing strength problem. These conversions require extensive machining, and at least one conversion makes the car extremely sensitive to water leakage thru the inadequate bearing seals provided. In my opinion, tapered rollers are completely unnecessary on a Pantera, and billet axles are also unnecessary unless you intend to roadrace the car in long endurance events with gumball racing tires.

Hey Boss,

Thanks for the info. You are, of course, correct. The axle had wear and we had it welded up. I will replace the bearings too, since everything is taken apart.

R.

The new clutch from PI came in, but the bolt patern doesn't fit the flywheel. I knew that would happen. Now I'm ordering a new flywheel (probably aluminum) and it will be here late next week.

I am horrible at waiting.

R.