sudden increase in clutch freeplay on '82
08-21-2001, 01:28 PM
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Cruisin'
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sudden increase in clutch freeplay on '82
Colleagues-
I've owned an '82 928 for about a month. The car is generally in fine condition, 1 owner (an old friend who just retired), 66,000 miles. At around 55,000 miles, 6 years ago, the clutch was upgraded to the latter single-plate design.
Driving the car the other day, the clutch freeplay suddenly increased from a few mm to about 20mm. There's a sticking action also, with 1/10 shifts requiring a pull back with the toe to release the pedal. Nothing obvious has changed in the adjustment mechanism. The manual alludes to this very problem, with only encouragement to visit a Porsche dealer.
Slave cylinder? Any other suggestions? I am minimizing driving until I have a handle on this.
Best Regards,
D.Lundgren
I've owned an '82 928 for about a month. The car is generally in fine condition, 1 owner (an old friend who just retired), 66,000 miles. At around 55,000 miles, 6 years ago, the clutch was upgraded to the latter single-plate design.
Driving the car the other day, the clutch freeplay suddenly increased from a few mm to about 20mm. There's a sticking action also, with 1/10 shifts requiring a pull back with the toe to release the pedal. Nothing obvious has changed in the adjustment mechanism. The manual alludes to this very problem, with only encouragement to visit a Porsche dealer.
Slave cylinder? Any other suggestions? I am minimizing driving until I have a handle on this.
Best Regards,
D.Lundgren
08-22-2001, 12:17 AM
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I'm not sure if this applies in your case or not. When my slave went out on my '82, I could see/feel brake fluid from the inspection port just below and behind the slave. My failure was total and the pedal just went to the floor and stayed there so I'm not sure if you're cause is the same. Easy to check though to see if there's fluid there where it shouldn't be. I think the pedal adjustment is just "pre-load" and spring tension on depression. Hopefully someone w more specific knowledge will post also, this is just what happened w my car.
Jim
Jim
08-22-2001, 02:45 AM
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Burning Brakes
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D.,
Though my 928 is an a/t model, I have had many a manual car in my life. Your symptomology is consistent with a master or slave cylinder failure. In my experience, slaves usually go first, as they are located in one of the least hospitable environments on your car (YMMV). If you are going to the trouble of replacing a slave, I would replace the master too - it has just as many miles, and the newfound "load" of actuating a fully functional slave will put more stress on an already old master. Point being, for another ~$75 just do both, or risk having to do it all again in the near future.
The easiest way I have found to determine which one died first, is to have an assistant push the clutch pedal and watch for movement of the slave. (I haven't tried this on a 928, so, as many things Porsche, it may be less than easy.)
Good Luck,
Greg
Though my 928 is an a/t model, I have had many a manual car in my life. Your symptomology is consistent with a master or slave cylinder failure. In my experience, slaves usually go first, as they are located in one of the least hospitable environments on your car (YMMV). If you are going to the trouble of replacing a slave, I would replace the master too - it has just as many miles, and the newfound "load" of actuating a fully functional slave will put more stress on an already old master. Point being, for another ~$75 just do both, or risk having to do it all again in the near future.
The easiest way I have found to determine which one died first, is to have an assistant push the clutch pedal and watch for movement of the slave. (I haven't tried this on a 928, so, as many things Porsche, it may be less than easy.)
Good Luck,
Greg
08-22-2001, 07:12 PM
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Greg,
I haven't replaced the master but recall reading that it's a real PITA whereas replacing the slave (which I have done) is very easy. The other thing I've read is that you can relatively easily 'rebuild' the master by removing the core from the drivers/clutch pedal side and replacing it w the core from a new unit...the old casing is supposed to be pretty sturdy and not likely to be worn.
Jim
I haven't replaced the master but recall reading that it's a real PITA whereas replacing the slave (which I have done) is very easy. The other thing I've read is that you can relatively easily 'rebuild' the master by removing the core from the drivers/clutch pedal side and replacing it w the core from a new unit...the old casing is supposed to be pretty sturdy and not likely to be worn.
Jim
08-23-2001, 02:25 AM
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Burning Brakes
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Jim,
Yeah, I've read that about the master too. It was in the Int'l catalog. If it's a PITA to replace, then the cylinder/seal trick may be the way to go.
My only intent was just to highlight the possibility of a bad master, and perhaps free you from the joy of bleeding the system twice if it went south shortly after the new slave. (ask how I know...)
Good Luck,
Greg
Yeah, I've read that about the master too. It was in the Int'l catalog. If it's a PITA to replace, then the cylinder/seal trick may be the way to go.
My only intent was just to highlight the possibility of a bad master, and perhaps free you from the joy of bleeding the system twice if it went south shortly after the new slave. (ask how I know...)
Good Luck,
Greg
08-23-2001, 09:30 AM
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D.,
I had the same thing happen to my '82. It turned out to be my slave cyclinder leaking which would drain out the inspection port in the clutch housing. Check the brake/clutch resevoir fluid level, you are probably getting air into the master cyclinder since it is draining out somewhere. I also ended up replacing the master cyclinder (it is a PITA job which requires you to contort your body unnaturally) and to my surprise the brake vaccuum booster was filled with brake fluid. I would recommend replacing both master and slave brake cylinders.
Good Luck!
I had the same thing happen to my '82. It turned out to be my slave cyclinder leaking which would drain out the inspection port in the clutch housing. Check the brake/clutch resevoir fluid level, you are probably getting air into the master cyclinder since it is draining out somewhere. I also ended up replacing the master cyclinder (it is a PITA job which requires you to contort your body unnaturally) and to my surprise the brake vaccuum booster was filled with brake fluid. I would recommend replacing both master and slave brake cylinders.
Good Luck!
09-07-2001, 02:47 PM
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Cruisin'
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Colleagues-
Thanks for the feedback, vacation inserted a delay into closure of this topic.
I'm happy to report that Dana & Devin at Hi Tec Automotive in San Rafael, CA (415 258 9619) looked into the clutch freeplay, and identified the adjustment rod to the master as loose past its end of travel. A quick adjustment and the clutch is as new, with master & slave cylinders certified as unmolested.
While they were at it, they also fixed a glitch in the accelerator linkage, tightened down a clamp to cure a slight exhaust leak, and charged my AC. For all this, 1 hour of labor plus the refrigerant. Overall, a terrific experience with Hi Tec, and 928 service in general. Thanks for the responses.
Thanks for the feedback, vacation inserted a delay into closure of this topic.
I'm happy to report that Dana & Devin at Hi Tec Automotive in San Rafael, CA (415 258 9619) looked into the clutch freeplay, and identified the adjustment rod to the master as loose past its end of travel. A quick adjustment and the clutch is as new, with master & slave cylinders certified as unmolested.
While they were at it, they also fixed a glitch in the accelerator linkage, tightened down a clamp to cure a slight exhaust leak, and charged my AC. For all this, 1 hour of labor plus the refrigerant. Overall, a terrific experience with Hi Tec, and 928 service in general. Thanks for the responses.
