Hydraulic clutch problem?

Hi,

95 Cavalier 5-spd with non-adjustable Hyd clutch, 90k miles. No clutch work done recently.

From a standstill the trans grinds when I try to get it into any gear. While driving, it grinds between gears. From a standstill it almost won't go into reverse, unless forced (bzzzzzzzzzzzzzzz-clunk!)

The clutch plate doesn't seem to slip at all. I've tried to get it to slip at all RPM speeds, and gears. Won't slip.

If I select 1st gear at a standstill, the clutch engages as soon as I lift my foot. It seems like the clutch plate is not seperating enough when pedal is fully depressed.

Over the past week the problem has gotten progressively worse. I don't think it is the clutch plate as it doesn't slip.

Does it sound like air in the line?...Any ideas?

Reply to
Urban Sherpa
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Reply to
Mike Walsh

The only possibilities I can come up with based on your description:

Air in the lines - Cure: Bleed the system. Price: zero unless you count beer for your helper (generally it's a two-man job, not because it takes muscle or any particular skill, but because one man just doesn't have arms long enough to reach what's needed while working the clutch pedal at the same time, and no eyes-on-stalks to be able to see what needs to be seen from the seat) and brake fluid - probably less than 15 bucks, if that much. Time: 20 minutes or less - probably less.

Master and/or slave cylinder cups/pistons/seals failed/failing - cure: rebuild or replace clutch master and/or slave cylinders. - Cost: Dunno for your Cav. For my Mazda, $30.01, out-the-door, for the two rebuild kits, or $80-something for a new/reman master and slave. Can't imagine it'll be all that much more for yours. Time: For mine, 15 minutes to pull the slave cylinder, 5 minutes to do the actual parts-swapping that's required, another 10-15 to put slave back on car. 10 minutes to pull master cylinder, another 5 to rebuild it (Again, just parts-swapping), 10-15 to put it back on, and 20 minutes plus fluid and a helper to bleed the system afterwards.

This is the one I'd be most inclined to think will cure your problem, but I freely admit that I may be biased, since I just had to cure this problem less than a week ago myself. It's a bit on the "shotgun" side of mechanic-ing, but at least for me and my car, it's basically painless, and covers all the reasonable possibilities.

Two other options, much less likely than the other two:

Hose or other hydraulic line leaking, swelled, softened, ballooning, or otherwise defective - Cure: Replace. Cost: negligible - 5-10 bucks, maybe. Time: 5 minutes for the swap, 20 minutes to bleed the system.

Clutch reservoir empty/low - Cure: Fill it! Cost: Brake fluid. A smart man will want to bleed the system afterwards, so 20 minutes or so of time, and a helper.

Reply to
Don Bruder

Could it be weak clutch plates? prob .8 I would replace clutch plate, throwout bearing, and resurface or replace flywheel while your in there.

Good luck!

This is not an estimate, or diagnostic: it's just me

-Ed

Reply to
Meineke

What are the symptoms of a throwout bearing going bad?

Reply to
bobby

"bobby" wrote

Nothing that the original poster is describing.

Ian

Reply to
shiden_Kai

I was dumbfounded by a Toyota hydro clutch once..I.rebuilt the slave and the master cylinder thinking the clutch wasn't bad because it grabbed good. The pressure plate fingers were the culprit. So after a pilot.bushing, resurface, new throwout bearing , reman clutch and plate, It was just fine.

Reply to
TOLYN9

info.

Reply to
Anthony Diodati

Reply to
Anthony Diodati

Completely different from ANYTHING he described in his post. Assuming his description of symptoms is accurate, his throwout bearing (not to mention his pressure plate, and clutch disk, and flywheel, and pilot bearing) is perfectly fine. He's got a problem in the hydraulics, almost certainly involving the cups, pistons, or both inside the clutch master and/or slave cylinders. And as I said yesterday, it's a quick, cheap, and brain-dead-simple fix.

Reply to
Don Bruder

While I agree that it is indeed *POSSIBLE* for the clutch itself to have gone south, his description makes that sound *VERY* unlikely.

Worst case scenario: Assume it's *JUST* the hydraulics that are broke. Fix them for 30 bucks and an hour of dinking around in the garage. *IF* the car is still broke after the cylinders have been rebuilt, *THEN* start going after the "pricey" and time-consuming stuff like dropping the tranny, replacing the clutch plate, bearings, etc. But *NOT* before going after the much simpler, cheaper, and higher-likelihood failure modes.

Going straight to the clutch itself is (IMO) foolhardy, for several reasons, including:

1) Failure of the clutch disc/pressure plate/flywheel/bearings generally doesn't act anything like what he's describing. With that failure mode, you're much more likely to see "The clutch won't grab", or "It makes a god-awful racket when I step onto/step off of the clutch pedal", rather than "the clutch won't let go so I can shift" that he's describing. Your scenario is NOT impossible, but it's much less likely, especially since he describes the probelm as coming on gradually, rather than all at once, as I'd expect for a clutch with busted throwout fingers, failed disc, or pressure-plate friction-welding itself to the flywheel after the car has been driven *WAY* beyond the point where the clutch disc failed catastrophically. 2) The suggested course of action (rebuild the cylinder(s)) is a much cheaper "first swat" at the problem, and based on the description of symptoms, *MUCH* more likely to actually cure things. 3) Should the rebuild *NOT* cure the problem, you've taken one more step on the "go/no-go" troubleshooting tree - You *KNOW* (Well, given the reality of "dead despite being new" parts, you can *REASONABLY ASSUME, BARRING CONTRARY EVIDENCE*) that the problem isn't the cylinders, and can start focusing on the clutch itself.
Reply to
Don Bruder

Agreed, 110%. If the clutch fork isn't moving in response to pedal activation, you've just nailed it down, with absolute certainty, that either one or both cylinders are toasted, the hydraulic line between them is blown wide open, the reservoir is empty, or a combination of any/all of the three. Nothing else that I can think of can possibly be wrong to cause that particular symptom. No, wait... I take that back... I guess the fork might be jammed somehow. If the throwout bearing were to "weld" itself to the input shaft so it couldn't slide forward and back, that would do it. Otherwise, I can't see any way to get the symptoms described. If the throwout bearing were frozen, though, I'd expect to be seeing a *HUGE* difficulty (possibly so huge as to make any motion impossible) in moving the clutch pedal, which the OP doesn't report, which leads me away from that option.

Let's don't invent problems for the guy, huh? All his symptoms point to "hydraulic cylinder or line failure". Other failure modes are, unquestionably, *POSSIBLE*, but with his symptom-list, I think those other possibilities are (or at least, SHOULD be) *WAY* down toward the bottom of the list of "potential suspects".

Reply to
Don Bruder

Thanks to everyone for the help. I'll follow the concensus, and check out the master, and slave cylinders. Ten years ago I'd be at the mercy of a mechanic,....with these newsgroups I can fix it myself,....and learn something in the process!

Thanks again guys,

-Karl

Reply to
Urban Sherpa

Reply to
Anthony Diodati

I'll second that motion!

I wanna know if I ended up right, wrong, or somewhere in between! :)

Reply to
Don Bruder

info.

Reply to
Anthony Diodati

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