espresso

New owner of an 85 GSL-SE, and new to rotary engines as well (at least as an owner rather than a technical writer).

The former owner of the car is a friend, and someone I trust to be straight with me about such things. He told me he replaced the master cyl., slave cyl. and line for the clutch before selling me the car. The line is clearly brand new; the master and slave cylinders are a bit hard to tell, as there is a bit of grunge on each of them (this is a 160k mile car that has been well-loved, so no huge surprises there).

The problem is such; depressing the pedal is fine, no weird sensation, deavticates the clutch while the pedal is still several inches off the floor. The problem comes when I hold the clutch in for longer than about 15-20 seconds. Apparently the pressure is leaking back into the reservoir or something, as the clutch engages more and more quickly when letting off the pedal, to the point where keeping my foot on the floor long enough would still allow some engagement of the clutch, and the car would die. This has been getting slowly worse over the few days I've owned the car (less than a week, but I've put about 900 miles on it in that time). At its worst, the pedal now no longer springs back when this problem manifests badly, and I have to flick it back to its resting position with my left toe.

After letting it back to rest position, it works fine again, at least until you hold it down for a good long while again.

I don't do hydraulic clutches, so I am left guessing a bit. It seems to me that the problem would be in the master cylinder, since it does not appear to be losing any brake fluid. If the pressure is leaking past the piston and back into the reservoir, that would account for the problem. I can't think of anything else that might cause this; I should have a slipping clutch and a loss of hydraulic fluid if the slave was leaking, and neither of those symptoms is present. I figure as a long shot it could just be air in the line, but I'm leaning toward my initial supposition.

Is there any known weak point for the clutch hydraulics on FB cars? Does this symptom scream something obvious to non-n00b FB owners?

Any and all help is appreciated.

Latin270

I'd start with replacing the Master cylinder 1st. Then take it from there.

Rx-7Doctor

iTrader: (13)

Welcome to the forum. There is a FAQ thread listed at the top of this section. That will become your main educator for your vehicle. There is also the search feature which you will learn also that will link you to info as well.

The hydraulic system for the clutch is no different then any other hydraulic system on another car.

You already know all the components. First thing to check even though you have no loss of fluid at this time is the pull back the rubber protective cup on the slave cylinder and verify it is not wet with fluid. If it is then that is your starting point. Replace the slave and rebleed.
If not, try rebleeding the system, if that is good and does not correct the problem. Then you need to replace the clutch master.
Good luck and let us know what you find.

Rogue_Wulff

Welcome to the forum, and the dark side.
From your rather well worded explanation, I would venture to say that you have already diagnosed the problem accurately. The clutch master seems to be bypassing internally.
I would start by asking the former owner if they bought a new master, or a reman, or if they simply bought a kit and rebuilt it themselves, and when this was done. If the work was done recently, it could just be a defective part. If it has been a while, the master may have gone bad. Just because a part is "New", does not always mean it is also "Good".

Anex 570

The same thing just happened to me and caused me to get a tow home from the mall for $75. Very embarassing. First thing you should do it replace the slave, as that is was failed on me after the same symptoms. I couldnt see any fluid leaking or anything, until it was too late and it shot the piston of the slave out the end so it couldnt retract, or work.

espresso

Thanks for the welcome, and the info. I was just wondering if that set of symptoms was especially indicative of a particular known issue. I've read most of the FAQ on the FBs, as well as a number of other FAQs and tech papers elsewhere, and my first step was to download the factory shop manual in PDF form.

In addition to the 6 bikes in various stages of repair and rebuild, and the Audi Coupe GT, looks like I have more weekend projects on my hands. If anyone is in the SF Bay area and wants to lend advice, tech knowledge, diagnostics, or what have you, I'm buying the beer and charred animal flesh of your choice.

Rogue_Wulff

If it weren't for the whole ~2K miles between here and there, I'd take ya up on that offer.

espresso

Yeah, I can see where that would make it more than a Sunday afternoon sort of thing.

If you're ever out this way... Or vice versa.