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Discussion Starter · #1 ·
Hi,

I had a new clutch installed just over a week ago. While driving home, I was a little overzealous and the clutch slipped in 5th while boosting. This is my first new clutch so I called my mechanic (certified Saab) thinking something was wrong. He got a little mad at me saying that I was to stay out of boost for at least a week or two while the surfaces mate properly. Anyway, I was driving home today (carefully as usual) but had to accelerate a little harder than I have been in 4th. The clutch started to slip again. It's been 300 miles since the clutch was installed and I'm concerned that somethings still wrong. The bite point seems a little high to me, also. The pressure plate, friction plate, slave cylinder and throwout bearings were replaced with OEM parts.

I'd really appreciate any help - I'm not too familiar with new clutches. If it's still doing it by this weekend then I'll be taking it back.
 

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I'm not exactly sure where I heard this or if it's true but if I recall correctly, A brand new clutch will slip some until it is broken in. I remember reading it somewhere on here. When I replaced my clutch I didn't experience any slip so I'm sure this probably doesn't help at all but I'm also light on the pedal.
 

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A new clutch shouldn't slip; ever.
He got a little mad at me saying that I was to stay out of boost for at least a week or two while the surfaces mate properly.
Horse manure.


Sometimes the master cylinder or the clutch line, either the one from the reservoir or the pressure line, will fail and not allow the clutch fluid to return. This can be diagnosed by loosening the bleed screw when hot (after the fluid has expanded) to see if there is pressure built up.


Edit: If the brake master cylinder is replaced, and the installer fails to cut the plastic nipple on the reservoir that allows clutch fluid to flow (the tubes come sealed in case there's no clutch) the clutch will fail because fluid can't return to the reservoir. This usually isn't discovered until you try to bleed the new clutch.
 

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It sounds like something simple like air in your hydraulic line, they guy probably did not bleed it through enough leaving some air in the pipe.

I have also never heard of a brand new clutch slipping and not on here for sure.

Did you have the flywheel machined? its technically the best thing to do for real longevity, its not essential but apparently it's the best thing to do.
 

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I am sorry to say that something is very wrong. The most obvious thing I can think of is an oil leak. Did the oil seals get replaced too? The clutch should not be too high. If no oil leak, I would try to bleed the clutch. Before I tried to bleed it I would crack the bleeder screw on the slave. If brake fluid spurts out, you've found your problem. I had a defective slave once, but it would loose pressure, not hold it. It is also possable, but unlikely you have a defective pressure plate. Now that I think of it, you paid to have all this fixed. I would bring it back and politely ask them to take a look. This should be there problem, not yours. Keep us posted.
 

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I'm with Jim - the only time I've had a new clutch slip (quite a few over the past 30 odd years across a variety of vehicles) was when I screwed up and didn't clean / resurface the flywheel. Something is amiss - either in your hydraulic system or there's spooge on the friction surfaces.
 

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3 weeks ago, i DIY'd a new clutch (plate, disc, slave, release bearing, and pipe) and have not had any slippage... admitedly, i may need to bleed the system again, as the bite is nt quite right, and its been a sticky going into 2nd on 1 or 2 ocaisions, but 100% no slippage... your mech must have ballsed something up ;oops:

G
 

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Every new clutch in my SAAB has slipped right away. It usually took about 500 miles for it to tighten up to the point where it holds on full boost.
The key is to not slip it very much when new. If you glaze the clutch disc by too much slipping, it will never break in.

This is pretty easy to see when you complain about it to the mechanic, so be careful when you bring it back! Otherwise, you will be buying a new one with no warranty!

My car probably has too much power for the clutch I have installed. I should get a stronger one and that might hold better when brand new. Currently it only slips on a nice cold day when making absolute max power.
 

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Matthew said:
There must be some allowance for the friction disc to bed into the flywheel, much as new brake pads take time to bed into the disc.
I've neither made allowance nor had a new clutch slip; ever (I've done many).

Of course if you've modified the engine to produce more power than the clutch is rated for, slipping can occur at any time. But that won't happen on a stock SAAB with the right parts installed; ever.
 

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Jim Mesthene said:
I've neither made allowance nor had a new clutch slip; ever (I've done many).

Of course if you've modified the engine to produce more power than the clutch is rated for, slipping can occur at any time. But that won't happen on a stock SAAB with the right parts installed; ever.
Unless, of course, you don't prep the flywheel correctly. The couple times I've skipped that step I've ruined new clutch disks (note- I might have been able to clean the parts and re-use them - but I didn't bother trying). I've also had bad luck (well, only once, really) re-using pressure plates as they tend to weaken a bit over time.
 

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SteveTheFolkie said:
Unless, of course, you don't prep the flywheel correctly.
I don't buy it.
If the flywheel is rough, for any reason, the clutch grabs or chatters, it doesn't slip.
 

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Jim Mesthene said:
I don't buy it.
If the flywheel is rough, for any reason, the clutch grabs or chatters, it doesn't slip.
in the case where I had a failure I didn't clean the surface well - there was some residual oil (my own fault - the rear main seal had failed - I replaced it but was rushing to put stuff back together) - hence the problem.
 

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SteveTheFolkie said:
I didn't clean the surface well - there was some residual oil.
Some carb or brake spray cleaner would solve that problem in a few minutes no?

How many different companies make frictions plates fort the c900?

I doubt they all use the same friction material so it could just be the type or brand of clutch he has?

By the way you didn't say the master cylinder was replaced did you.

I say give it a week and if its still slipping go back and tell the mechanic, I'm sure he will sort it out if he is a salt of the earth kind a guy.
 

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Discussion Starter · #17 ·
First off, sorry for having not replied to all of you excellent posts - I only got an email for the first post!

Anyway, I've been driving very carefully with it since having the clutch installed and that's been about 400 miles of driving now (2 weeks). Yesterday on my way home I was accelerating to merge with traffic and it was slipping again...after experimentation, there's slippage in 3rd, 4th and 5th so I'm pretty hot right now :evil:. The whole point of taking it to a mechanic was to get it done right....

I'm going to call my mechanic as soon as he's open with Thanksgiving and get it booked in again. I'll certainly not be paying a dime more....

To be fair, I have no reason to believe that my mechanic's going to give me a hard time - he's always been decent in the past.

Oh, and ShadowWorks, the master cyclinder was not replaced...

I really appreciate everyones feedback and will let you know the outcome.

Thanks again,

Chris
 

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Discussion Starter · #18 ·
Oh, reading Steve's post, the rear main seal had also failed so it was replaced, perhaps lending itself to a contamination issue??
 

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Discussion Starter · #19 ·
Just an interim update. I called my mechanic and he was very responsive to the problem. I'm going to drop it off for him to check it over on Monday. He mentioned that there were a few things he wanted to check out before pulling it apart, obviously. I'm just hoping he can't find anything to 'blame' it on that's going to cost me more pennies...of which I don't have many!!
 

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Discussion Starter · #20 ·
Ok, it's been a while but fingers crossed it's all good now! I took it back to my mechanic and he was able to reproduce the slipping in 3rd, 4th and 5th gear. He was obviously really unpleased about it and to cut a long story short, he couldn't find anything wrong on the outside so opened it up again. He called Saab and they provided him with a replacement clutch which he installed and the same results were apparent. He did some more research and decided to try and go with the Borg & Beck clutch that Saab used originally instead of Sachs, who they now supply. Apparently the springs on the pressure plate are stronger and having installed the Borg & Beck clutch he said there's a world of difference. It was also nice to hear that I'd treated the clutch well since it was still in great condition! I'll be picking her up tonight so fingers crossed it'll be good to go.

I have to say that if anyone is in the Philadelphia area, I've got nothing but good things to say so far about Demi at Precision Plus Imports (http://www.precisionplusimports.com/). There was no charge for the work he has just completed (technically 3 clutch jobs) so I'll certainly be going back again.

If you don't hear back from me again then you know there weren't any problems!!!
 
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