Accumulator confusion.
#1
Accumulator confusion.
Ok I've read a bunch of info on this and other forums, read the service manual, 996 Essential Companion and asked my friends that are techs at the dealer some time ago.
My clutch pedal is always hard except with the motor running. It I shut the car off for 5 minutes, the clutch pedal is as hard as if I haven't driven it for a few days. If I pump it, it doesn't get harder, it's always hard, again unless the motors running. Also some times when I press the clutch instead it being totally fluid and evenly consistant it's a bit juddery or slightly inconsistant.
Does this sound like an accumulator issue?
My clutch pedal is always hard except with the motor running. It I shut the car off for 5 minutes, the clutch pedal is as hard as if I haven't driven it for a few days. If I pump it, it doesn't get harder, it's always hard, again unless the motors running. Also some times when I press the clutch instead it being totally fluid and evenly consistant it's a bit juddery or slightly inconsistant.
Does this sound like an accumulator issue?
#6
I just got my car recently and had a similar issue on Sunday. The clutch pedal required a little more effort, and the travel was a bit jittery (not smooth) as you describe. It went away after I pushed the clutch in and out a bunch of times at a stoplight, but came back when I started the car later that night.
#7
Ok I've read a bunch of info on this and other forums, read the service manual, 996 Essential Companion and asked my friends that are techs at the dealer some time ago.
My clutch pedal is always hard except with the motor running. It I shut the car off for 5 minutes, the clutch pedal is as hard as if I haven't driven it for a few days. If I pump it, it doesn't get harder, it's always hard, again unless the motors running. Also some times when I press the clutch instead it being totally fluid and evenly consistant it's a bit juddery or slightly inconsistant.
Does this sound like an accumulator issue?
My clutch pedal is always hard except with the motor running. It I shut the car off for 5 minutes, the clutch pedal is as hard as if I haven't driven it for a few days. If I pump it, it doesn't get harder, it's always hard, again unless the motors running. Also some times when I press the clutch instead it being totally fluid and evenly consistant it's a bit juddery or slightly inconsistant.
Does this sound like an accumulator issue?
There's a couple of tests you can do...
Checking accumulator: Pentosin CHK 11 S is the only fluid you should use in the reserviors.
Do not turn the wheel or depress the clutch pedal with the engine off as this can change the fluid levels.
Cold start the engine (accumulator temp at approx. 20C) and let the engine idle for approx 20 seconds. Turn off the engine. Depress and release the clutch pedal repeatedly until an abrupt rise in pedal resistance against your foot can be felt. Count the number of pedal depresses. If the number is over 35 the accumulator is bad and should be replaced.
If there is no hydraulic clutch boost after a hold time of 24 hours at least one of the two valves in the clutch slave cylinder is bad.
In my car's case the clutch pedal was hard after the car sat just a few hours (0or less) after the engine was last run.
Once the engine started the clutch pressure got easy again but as I worked the pedal I could feel some pulsing. This is the pressure pump working. The accumulator tends to mask/dampen the pulsing when it is working.
I do not recall how many times I could depress the clutch before the pedal got hard.
Lastly, I spotted a fluid leak coming from the clutch reservior at the front of the car under the plastic panel on the driver's side. The fluid was on top of the panel. When I relayed the fact there was a fluid leak both senior techs said 'clutch slave cylinder' in unison.
Keep an eye on that reservior: You do not want that Pentosin fluid to get on paint or rubber hoses. It is water soluble though.
Added: In a PM Dock questioned the 'over' 35 pushes part and even though this is the wording in my info source I think the 'over' should be 'under'. IOWs, if the accumulator and accumulator charging circuit are working properly the accumulator should have enough energy accumulated after approx 20 seconds of engine idling time before being shut off to support at least 35 clutch pedal depresses before the pedal resistance gets hard.
Sincerely,
Macster.
Last edited by Macster; 05-31-2011 at 06:45 PM. Reason: Added: "Added:..."
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#8
The accumulator is only there to work when the car is turned off. It stores pressure to lighten the clutch pedal feel. When the pedal is hard while the engine is off, it is the sign that the accumulator has failed. Once the car is running, hydraulic fluid is circulated by means of the engine, and the clutch pedal is light.
#9
Nick, If you're going to do the accumulator, you should seriously concider doing the slave cylinder as well. They typically fail in succession. The labor isn't terribly more to do the extra part, so I'd just do them both and be done with it...
The Clutch Hydraulic system on the turbo is linked between the power steering system and the clutch system. Also be aware that the fluid used for the system has a high igniting flash point and eats rubber... It's a nasty substance that should not be allowed to leak down on to the motor. It's flamable (especially around turbos and Cat/converters) and loves to cause water leaks due to the damage to rubber hoses...
Mike
The Clutch Hydraulic system on the turbo is linked between the power steering system and the clutch system. Also be aware that the fluid used for the system has a high igniting flash point and eats rubber... It's a nasty substance that should not be allowed to leak down on to the motor. It's flamable (especially around turbos and Cat/converters) and loves to cause water leaks due to the damage to rubber hoses...
Mike
#10
True, but the accumulator stills dampens the pump's working. I could feel the pulsing and spoke to a tech about it. He said it was ok, just the pump, and it wouldn't harm anything to continue to drive the car like that.
In fact he told me one customer who had owned a Turbo a long time (I can't remember the length of time or miles) brought his car in for something else and during a check out the clutch accumulator was found to be bad. The owner was informed and agreed to have it fixed. When he picked up the car afterwards he told the service department that the car had always had that hard pedal after the engine was shut off a while.
Fluid overflowing from the slave cylinder reservior is a symptom of a failing/failed clutch slave cylinder. When the fluid started showing up coming from a the clutch slave cylinder reservior that is when the techs told me it was time to bring the car in.
Anyhow, after the accumulator was replaced I could no longer feel the pulsing in the pedal.
Sincerely,
Macster.
In fact he told me one customer who had owned a Turbo a long time (I can't remember the length of time or miles) brought his car in for something else and during a check out the clutch accumulator was found to be bad. The owner was informed and agreed to have it fixed. When he picked up the car afterwards he told the service department that the car had always had that hard pedal after the engine was shut off a while.
Fluid overflowing from the slave cylinder reservior is a symptom of a failing/failed clutch slave cylinder. When the fluid started showing up coming from a the clutch slave cylinder reservior that is when the techs told me it was time to bring the car in.
Anyhow, after the accumulator was replaced I could no longer feel the pulsing in the pedal.
Sincerely,
Macster.
#11
#13
Well, no other chioce is not accurate, of course, because I could have rented a car without any real hardship. Had the techs said do not drive I would have parked the Turbo and gotten a rental car, pronto.
But it all worked out ok. In fact maybe better maybe the continued use of the car with the accumulator kaput accelerated the demise of the clutch slave cylinder? Since the car was covered by a CPO warranty I didn't fret it too much.
Now if the same thing happens again -- the accumulator goes out again -- and the car is out of warranty, I might park the Turbo rather than to continue to drive it to protect (just to be safe) the clutch slave cylinder.
Sincerely,
Macster.
#14
Well I have to admit I can't speak from experience on this. But when I bought my car last month I had TPC Racing do the PPI, and the shop manager told me that the failed accumulator on my car was nothing to worry about, and as long as I didn't mind the extra legwork on startup I could ignore it.
If that's not true I guess I have a bone to pick with TPC Racing.
If that's not true I guess I have a bone to pick with TPC Racing.
#15
The accumulator is only there to work when the car is turned off. It stores pressure to lighten the clutch pedal feel. When the pedal is hard while the engine is off, it is the sign that the accumulator has failed. Once the car is running, hydraulic fluid is circulated by means of the engine, and the clutch pedal is light.
It feels almost electric - it's virtually impossible to tell where it's biting, and even slightly quick getaways are impossible. If I had to list the negative points of the turbo, the clutch would be pretty near the top (if not at the top!).