Clutch Hydraulics Diagnosis

[corynoack]

I am working on a 93 sl1 I just rebuilt the motor and replaced the clutch now when the clutch is pushed it is really soft and the motor won't start

[JerryHughes]

Originally Posted by BarnOwl

This one comes up enough that I'm going to get it made into a How-To.

Symtoms

The car is hard to shift especially into 1st or reverse while running but, will shift smoothly with the engine off.

Quick Tests

On a level surface, with the engine running, hold the clutch in for a minute or two. If the car starts to creep forward after waiting a bit, it's a good indication that the problem's hydraulics. If it starts to creep right away, it could be another problem.

When the car is hard to shift, try pumping the clutch a few times. If it gets easier to shift, it's probably a hydraulic problem. If not, you really don't know.

While the above tests will give you a pretty good idea what's going, on they are hardly definitive. Given that the price of a clutch hydraulic assembly is more that $100, you really want to be right when you buy one.

The Definitive Test

First check the clutch pedal travel as shown in the picture below. It needs to be 135 mm to 156 mm (5.3 - 6.2 in). If it isn't, there's some obstruction or the dash is damaged.



If the pedal travel checks out, there's a small access hole next to the slave cylinder (see pic below). Stick a piece of stiff wire in that hole till it touches the fork and mark the wire where it goes into the hole. Do the same thing with the clutch pushed all the way in. The distance between the marks should not be less than 11.18 mm (0.44 in). If the distance is too small, it's the hydraulics. Otherwise, your looking at a damaged fork or pressure plate.

Thanks, BarnOwl, I will look at this today when it's light out. Early here. Would you know if these tests apply to a clutch even though my clutch only is hard to shift, certain times? Half the time the clutch shifts like it's brand new. And again, I have had that clutch replaced about seven years ago and I drive like an old lady when it concerns the clutch. But the car does shift just fine when the car is shut off. But I haven't tried that test when I'm having trouble shifting. I will pull over and shut the car off when having problems shifting to see if it shifts okay when the car is then off. And I will look at the other tests too. Thank you for all the help. Keeping my fingers crossed that it's only dirt in the fluid and may change the fluid today. Thanks again.

[crobey]

After several months of difficult shifting I found this article. Spot on!! Since it happened over time I didn't notice the clutch engagement spot moving closer to the floor, but that is what happened. It went from 1 inch from the floor to about 2 inches from the top after replacing the master and slave unit.

If you are going to make the change, just go ahead and change out your motor mount while you have everything taken apart.

Also if you have ABS you don't have to unbolt and move it out of the way but it will be very tight.

[AltxF4]

Wow! I am so glad I saw this thread! I just picked up a 120k mile 1997 SL2 (my 2nd saturn...old one was 96 SC1), and I feel like I it is a lot harder to change gears than my SC1 ever was, and the pedal is a lot lower to the floor. I will do these test in the morning. Clutch and MC/Slave kits are the same, but I'd much rather perform the labor involved in changing the MC/slave than the clutch!

[scottjk]

Back again!

I posted about a no-start/no-crank last summer, got some input and experienced the nightmare of swapping the starter. (After pulling the alternator and swapping the battery. I'm still emotionally scarred.)

My clutch bombed out, (clearly), and I had some symptoms prior to the failure.

1. Squeeky clutching over time, especially when it was hot out.
2. Needed to pump the clutch a bit from time to time to shift. <check>
3. Some fluid was expressed, so, on wet pavement, it looked like my poor girl wet herself (sheen on water). However, the fluid level in the master was fine. (loss of pressure at the slave?)
4. I didn't notice any change in the pedal travel. No play that I could discern. All the way up, all the way down. I'll call that good. <check>
5. Wire test? Hmmm, "Not less than 11.18mm"? I'll assume 10mm qualifies, and I'll also assume that 11.18mm is borderline to begin with. If you can't get that much travel, you start to have issues. <check?>

I suppose it's safe to assume it's the hydraulics? I'm praying it is. Pulling the engine is not something I'm looking forward to, and I can only burn $100 or so, at this point.

Those of you who can't seem to locate the inspection hole, on my 1997 SC2, there's a rubber dust boot around the slave cylinder, pressed flush against the housing. It's not hard plastic, so it can be pried away a bit. You'll find the inspection hole under the boot, next to the slave on the back side. I HAD to pull the battery, airbox, overpressure box, and battery tray to get at it. When you put the wire in, it MUST be perpendicular to the housing, parallel to the slave cylinder. Any angle will throw off an accurate measurement. I used a white coat hanger wire, btw, with a Sharpie.

My thanks to you, Barn Owl.
I hope this will get me back on the road.

Scott