MM54

Car is an '85 S with a non-original engine (I believe it to be from an '83 but I don't know for sure, it was in there when I got the car). I know nothing of the mechanical history before I got it a couple years ago. I've recently noticed my clutch engagement is moving up the pedal stroke, and I'm concerned that if it moves much more it will no longer fully engage (i.e. it starts to disengage pretty early when pressing the pedal). The clutch master and slave cylinders are only about a year old (I replaced them last spring-ish). Are these meant to be self-adjusting, should I adjust the linkage (I assume at the pedal, not quite the Z-bar I'm used to adjusting!), or is it more likely that the clutch is just plan worn out and I should plan on replacing it soon?

Thanks!

GSLSEforme

Yes,it has limited life left. There is no adjustment other than free play of@1/8”. Check that to be so,
If no free play,adjust pushrod free play by loosening12mm nut at clevis at pedal arm.

If you have free play,the clutch has a limited service life and plan on replacing it. Not a hard job.

MM54

Thanks, is that free play in "totally dead slop" or the zero-effort-but-still-pushing-the-master-cylinder? There is a tiny bit of lash in the linkage, then some travel where you can feel it's pushing the master cylinder but hasn't encountered resistance yet (yes it's well-bled).

LongDuck

In other words, if you're in the habit of resting your left foot on the clutch pedal, that 1/8" is just enough to help prevent undue slip of the clutch before the pushrod touches the piston in the Clutch Master Cylinder. Personally, I have very little free play, because I like the engagement without any take-up. If the Master and Slave cylinders are fairly new, as is the flexible line between them, it's likely a worn clutch disk as mentioned above.

If it's already slipping now, it's only going to get worse as the disk wears further.

Common parts "while-youre-in-there"; Clutch Disk (*obviously), Pressure Plate, Throw-out Bearing, Pilot Bearing & Grease Seal. Some even go so far as to replace the Trans Front Cover on which the Throw-out Bearing rides, and if you do that, might as well replace the gasket for that, too. Might not hurt to have a new Clutch Arm and Pivot Ball on hand, as most of our cars are up there in mileage. This last bit is admittedly overkill...

GSLSEforme

Look under dash for where clutch master cylinder is mounted.You can see back of clutch master and where pushrod goes into it. With your hand push clutch pedal in just to where you see the piston start to move,how much free play in pedal/linkage before pushrod begins to move?

That's what should be @ 1/8". If slightly more,not a problem. If no freeplay loosen lockut and rotate to where you have needed amount and tighten locknut. At the point pedal pushrod touches piston in cylinder it should be hard/not spongy. Any further pressure should be immediately moving clutch slave cylinder out. If you don't feel resistance on pedal the moment free play is taken up, you have air in system or worn out hydraulic parts. Try bleeding again to get proper pedal feel.

Regardless of clutch hydraulics,your clutch disc is worn thin and needs to be replaced along with pressure plate,t/o bearing. Replacing pilot bearing and grease seal would be a good idea. When you get clutch/pp off,look at flywheel carefully. Removing it and sending it out to be machined will give you a smooth long lasting clutch job. If you do this,replace rear main seal while flywheel is off. Mazda seal is best. Exedy 10806 clutch kit is good replacement for stock clutch in your car.

MM54

I will check if the play is before or after the master begins to move (I've bled it quite a bit, doubt there's a bubble somewhere but if so I'll put the vacuum bleeder on it) - either way though that wouldn't move things up the pedal, but rather down. I will anticipate changing the clutch somewhat soon; it isn't slipping at this point but I won't push it until I get the new one in - and yes I'll do the correct service including the pressure plate, TOB, and inspection of the flywheel, fork, pivot, etc. If the flywheel does need surfaced (likely), I'm vaguely concerned about getting the giant nut off, and moreso getting it back on torqued to spec. None of my torque wrenches go that high, but we'll burn that bridge when we get to it. Thanks guys!