Hello gents, once again I return for the good advice I’ve always gotten here.

On the 90 SE5 the clutch won’t disengage. We suspected the clutch master cylinder and replaced it. The slave cylinder is newer and has no leaks. We have bled the living crap out of the system and still no luck. It actually worked partially for a short bit so we bled more attempting to get it better but it wound up getting worse again and we can’t get it back. We made the pushrod adjustment longer, no luck.

Im beginning to think maybe the pressure plate is failing and won’t disengage the clutch from the flywheel.

How much movement should you get from the clutch fork when you depress the clutch pedal to the floor? The end of our clutch fork where the slave rod connects is moving about 1/2” on a full pedal depress. It will hold at 1/2” as long as the pedal is held down. But, is 1/2” enough movement?

Im trying to figure out if I still have a hydraulic problem or is it the pressure plate failing.

Thanks as always

 

Generally speaking, about this type of clutch system If you open the bleed valve and are getting a good stream of fluid without a lot of aeration, then it is not likely the hydraulics and more the pressure plate that is failing.

 

To clarify my problem, i cant put it in gear when the engine is running.

Hydraulic problem? , Bad pressure plate? Seized pilot bearing?

Clutch fork moves 1/2” on pedal depress. Is that enough?

 

We get good fluid flow during the bleeding process without bubbles. And like i said when you push the pedal to the floor, the slave pushes the fork back 1/2” and it will hold there as long as you keep the pedal down.

 

Well you did the same parts replacement as I would, and it reads the proper bleeding so that leaves either a damage bell housing component or worn pressure plate?

 

This makes me think it's a hydraulic issue. Those, I've experienced, and also a slipping clutch disc; never failure to disengage unless it was a hydraulic issue.


I've never adjusted the pushrod on mine in 29 years.

 

Can the clutch master cylinder have an internal seal failure but have no leaks at inner firewall?

 

Cusser is out more experienced member with these model Mazda's but between us we just basically targeted the whole clutch system. lol
As for all Hydraulic cylinders designed in that time period if it failed you would see bubbles in the reservoir and likely no movement or very small movement of the other clutch components and it would not hold pressure.
Just because the unit was new/rebuilt does not mean that it was a good unit?

 

Thanks for the replies. Can anyone tell me how far back the slave cylinder should be pushing the fork to get full disengagement?

 

I have had to install 3 NEW slave cylinders, before finding one that works good! Yes, on a B2200! Ain't it great that we can generally only get these that are made in CHINA? Sometimes these not-so-quality parts don't work too well right out of the packaging.
I think I would try another new slave cylinder first (cheapest route) and if that doesn't cure it, take the Clutch Master Cylinder back (warranty?) and exchange it for another. Let us know how it goes.