diagnosing clutch issues

OK, I seem to have some issues getting into 1st gear on a 1996 manual

4WD sport. Also you have to delay some to move to other gears. Pedal seems 'springy', or close to normal - hard to say.

When I switch the engine off, it slides into 1st effortlessly.

The clutch fluid level is correct.

I had a new clutch put in, including the slave cylinder 24K miles ago. Clutches in my vehicle normally last 70K-100K.

Could this be a failed master cylinder? The clutch level in the resorviour being correct makes me think that perhaps there is no fluid loss, or air is in the system. Would a slave cylinder failure make the level go down?

Puzzled...

Paul

Reply to
paul.scrutton
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OK, I seem to have some issues getting into 1st gear on a 1996 manual

4WD sport. Also you have to delay some to move to other gears. Pedal seems 'springy', or close to normal - hard to say.

When I switch the engine off, it slides into 1st effortlessly.

The clutch fluid level is correct.

I had a new clutch put in, including the slave cylinder 24K miles ago. Clutches in my vehicle normally last 70K-100K.

Could this be a failed master cylinder? The clutch level in the resorviour being correct makes me think that perhaps there is no fluid loss, or air is in the system. Would a slave cylinder failure make the level go down?

Puzzled...

Paul

Reply to
paul.scrutton

Well, still looking and searching. I noticed today that shifting is significantly easier if I clutch into neutral, and clutch into the new gear (think this is called double-declutching).

My current theory is that the master cylinder is weak, or leaking, or possibly not bled correctly, as that would explain the lack of fluid loss (ie. it's not coming out of the slave), ie. it's just not pumping well. Also, the master cylinder is original (240K miles on it). When I double-declutch, pumping it twice in quick sucession may be enough to get it to work well for a brief moment. Well, it's just a hypothesis. I shall investigate further this weekend.

Paul

Reply to
paul.scrutton

OK... is it "springy" (my term might be spongy) or is it normal..... There is a common problem with Ford fluid reservoirs... there is a rubber sock in the reservoir - often we see an empty reservoir but the sock is full of fluid. This would give your symptoms. Air molecules are smaller than brake fluid molecules... air can enter the system through several routes and deliver a spongy pedal. A faulty pressure plate can do it and a fualty disc might.

My first step would be to bleed the system.... after that, I'd need to experience the problem to be of much use.

Reply to
Jim Warman

Hi Jim,

After some reflection, I think that it feels normal. Its hard to put my finger on it. But overall, more 'normal' than springy. I already checked the sock in the reservoir, and there is no fluid above it, so the sock appears to be doing what it is supposed to.

Paul

Reply to
Paul Scrutton

After you engage first gear, how far off the floor do you get with the pedal before you can feel the clutch trying to move the car?

Reply to
Jim Warman

About half way up through the travel of the pedal.

Paul

Reply to
Paul Scrutton

First thing to do is try bleeding the system again. I have had a certain amount of luck inserting a suitable bar into the side of the bellhousing and carefully prying the release bearing rearward. Hold the slave collapsed for a couple of moments to allow any air to rise in the line. Gently release the pressure and repeat. If there is any air trapped in the system, this usually gets it high enough to be worked out with rythmic, slow pedal applications.

Another thing, if you have a spare master cylinder cover and a hand vacuum pump is to apply vacuum to the system from the top. You will need to modify the master cylinder lid.

If that doesn't work, there may be a problem with the clutch pressure plate. I can usually tell by feeling the clutch action but I can't quite reach your pedal from here 8^(

Reply to
Jim Warman

Well, after thinking about this some more, and noting that the problem was getting progressibvely worse, I decided to purchase a new clutch master cylinder and try installing it. I figured that some component was getting worse, and that as the internal components were all replaced 30K ago, and that the master cylinder was original with 250K miles on it, I decided that it had to be a candidate.

This plan does appear to have had some merit, as I discovered fluid residue on the outside of the old master cylinder when I got to it. I have since replaced the master cylinder (after bench bleeding it), and am about to bleed the brakes. I also discovered some fluid residue on the outside of teh brake master cylinder also (%^$% #$%^ $^%!).

I did have to fabricate a sleeve (out of a short piece of copper tubing) to replace the worn and aged plastic sleeve on the end of the hydraulic line. Sure enough this 5c piece of plastic isn't available as a seperate part. I'm hoping that the copper piece of tubing doesn't chemically weld itself to the line. It performs better than the plastic piece anyhow, and should last longer. The neighbourhood children learnt some new words when I was messing with that worn plastic sleeve I can tell you.

In order to give myself a fighting chance at being able to bleed them myself, I purchased a Motive Products Power Bleeder. I discovered that due to the small size of the base of the clutch resrvoir it was necessary to build a shim or jig to hold the chains in place, when getting a seal on the unit. I'm at the stage, where I have just finished construction of the shim. I hope to bleed the system in the next few days.

Paul

Jim Warman wrote:

bellhousing and

collapsed for

applications.

Reply to
paul.scrutton

Well, no good news. Replaced the clutch master cylinder. Bench-bled the system with master cylinder horizontal. Used a pressure system that worked by using a car tire as a air resorvoir to push the fluid through from the top of the resorvoir. Fluid coming out was bubble-free. Put about a quart of fluid through the system, following the bleeding procedure. Pedal response improved greatly during this time.

Pedal travel feels good and crisp, and you can see the clutch components moving through the inspection port. Travel starts almost immediately when you place your foot on the clutch. However, it is still very difficult to get into and out of a gear when the engine is turning.

Not sure how to proceed further, other than driving it down to a clutch/tranny repair specialist.

I did notice that there was no rubber boot over the inspection port on the bell housing, not sure if road debris/junk has gotten in there or what? I'll check the dealer this week to see if the boot is available as a seperate part, or whether I'd need to order a new tranny to get one (grin).

Paul

Reply to
Paul Scrutton

Yeas ago I had thsi sort of problem with a Datsun (aka Nissan) 280Z. Eventually the problem was traced to a bad pilot bearing.

Ed

Reply to
C. E. White

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