I just replaced my slave cylinder on my '95 F150 4x4 (while doing the clutch, pressure plate, etc.) but I haven't been able to bleed the slave cylinder. I've tried the slave cylinder manufacturer instructions to depress the clutch to force out the air, then close the bleeder valve (etc.), with no success. I've also tried the Haynes manual's method of just opening the bleed valve and letting gravity bleed the slave cylinder. Also, no success.

Anyone have an effective method? I remember a post from someone a long time ago saying he had good success using a bleeding tool of some sort. Any ideas?

 

Check with havack@broncodata.com . He just became an expert on this when he & I swapped his '93 E4OD for an '89? M5OD and he went in circles getting the right clutch system. He put a writeup on that site, so you may be able to find his bleed procedure there.

 

whenever i need to bleed any hydraulic fluid, brakes, clutch, etc. i use a little hand held vacuum pump. you can pick it up at any parts store. it comes with a small collecting cup, different hoses and fittings, and it is worth it's weight in gold when you are doing brakes (or slave cylinders)by yourself.

 

When using a vaccuum pump, do I bleed with the clutch in the up or down position?

Thanks for the help.

 

the position of the clutch pedal doesn't matter, just use the pump until you get no air bubbles at all coming from your slave cylinder. also while you are bleeding make sure you keep master cylinder full of fluid, if you pull in air you'll have to start pulling air out all over again. then tighten everything up and test your clutch by depressing pedal a couple of times, you may have to bleed once more after that, but that should do the trick.

 

I picked up a vaccuum pump, but it doesn't seem to help either. I attached the vaccuum line to the bleeder valve, pump up the vaccuum to 25 in. and open the bleeder valve. There's little or no fluid coming out. The little that comes out is in a trickle. There's plenty in the master cylinder.

I next removed the main fluid line again, checked it by depressing the plunger in the fitting a couple of times, then reattached it until it clicked into place. Still no change, although the master cylinder had more fluid in it, almost to the point of overflow. There were no problems with the master cylinder before I replaced the clutch.

What's going on? Am I missing a part? I removed the line from the slave cylinder before I removed the transmission, then reattached it later. That's all there is to it, right?

 

[updated:LAST EDITED ON 17-Nov-02 AT 07:26 PM (EST)]When you removed your clutch master cylinder cap to refill it with fluid, does it have a black rubber diaphram? When I was refilling mine after changing my clutch, I didn't remove the diaphram and was filling it instead of the master cylinder. I realized this when I disconnected the line going to the clutch slave cylinder and pumping the clutch. Of course no fluid came out of the line.

 

Yes, this is exactly what I was doing. The vaccuum pump pulled the diaphram to the bottom, and I burnt out my second floodlight for the engine compartment, so the lighting was poor.

Now I'm able to bleed the system. I've bled it repeatedly, but it's still not working as I expect. I'll keep at it until it works right.

Thanks for the help. I would have yanked the transmission before I thought of that!

 

It can take a while to bleed a new slave cylinder. If the hand vacuum pump doesn't work just pump the clutch and while holding the pedal down wedge a two x four from the pedal to the seat.

Go underneath and crack open the bleeder valve until the fluid or air squirts out then quickly close it. Pump the pedal again. Hold the pedal down and repeat the process until you get a solid pedal feel. Shouldn't take more than 10 minutes. With an assistant 5 minutes. Just make sure you keep the master cylinder full. When you're done, fill the fluid to the proper level and kind of fold the diaphram back up and put the cap back on.

 

I had to pump my clutch peddal like 1000 time...no sarcasm...according to my repair manual it said like 450 but after 500 it still wasn't engaging after I put the new slave in there but after 1000 pump's everything is all good.

 

Well, the vaccuum pump didn't work. I then started bleeding by depressing the clutch pedal. I've gone through ~24 oz. of brake fluid, and I haven't seen any bubbles in 20 or so bleeds, but the slave cylinder is only moving ~0.25 - 0.3 inches instead of the 0.425 the Haynes book says it should. I can't shift into any gear with the engine running.

I'm now attempting to respline the clutch lever to get the maxium stroke from the master cylinder pushrod. I haven't been able to pry the clutch lever off yet, and I'm afraid I'll damage it with my current frustration level.

If this doesn't work is my only alternative to rip everything apart and replace the slave cylinder? Man, I really don't want to do that!!!



(Day 10 of this clutch replacement and wishing I never started...)

 

[updated:LAST EDITED ON 19-Nov-02 AT 10:52 AM (EST)]Have you examined the clutch pedal linkage under the dash?
Take a good look at the plastic bushings.

Was the flywheel resurfaced and if so how much was cut?

Could be a bad clutch master cylinder. When you look under the dash where the clutch master cylinder comes through the firewall do see any signs of brake fluid?

Could be the clutch disk is installed backwards.

I wouldn't modify the clutch linkage to get the clutch to work. You need to find the actual cause of your problem.

Keep at it. I'm sure your patience will pay off.

 

Well, the plastic bushing was OK, but I broke it removing the MC rod from the clutch pedal. I've had to replace this before, and the MC rod another time.

The end of the MC rod has to be depressed about 0.25" to match the clutch shaft rod. According to the Haynes manual, these should match without any movement. I'm this is limiting the stroke of the MC rod. The Haynes manual says that if the slave cylinder is moving less than the expected 0.425", then it's either a bad slave cylinder, low fluid, or bad clutch pedal adustment. Since I'm hoping it's not a bad slave cylinder, I'm going to try this.

Yes, the flywheel was resurfaced, and this may have caused the slave cylinder to be a little further away from the flywheel. I would think that the clutch pedal adjustment would help this. I don't know how much was cut from the flywheel, but I can ask. I wouldn't expect more than a few thousandths.

No brake fluid under the dash, and it was working OK. I may replace it before I start in on replacing the slave cylinder.

The clutch was installed with the flat side to the flywheel. I checked this thoroughly before installing.

Thanks for the good advice and encouragement. The temptation to go buy some For Sale signs is getting greater every day!

 

The new MC went in last night, and I repositioned the clutch pedal lever to line up with the clutch MC rod. I then bled the system 40 times, long past when air was still coming out. Unfortunately, the slave cylinder is only moving 5/16", or 0.3125" instead of the necessary 0.425".

I'm going to bleed the system some more. If this doesn't work, then the whole thing's coming out and a new one's going in.

One BIG lesson learned for anyone else considering doing this yourself - bolt the transmission up (I'd think 2-4 bolts would be adequate) THEN, hook up the slave cylinder lines and bleed the system. That way there's a lot less to remove if the slave cylinder is bad.