WALTSTAR

driving along last week and the clutch went down and only came halfway up. I puled it up with my toe and it worked fine the rest of the day. Took it out this morning and after five minutes of over the road driving, it went down to the floor and stayed there. Pulled it up and it was as if the linkage wasnt connected at all. Got it home and am wondering which cylinder it is.. I intend to rebuild both as I dont want to do it twice. 1984 USA. Any hints?
Thanks.

dr bob

If you plan to rebuild both then no hints needed. Else: Look at the blue hose that connects the reservoir on the brake MC to the clutch MC, and the fluid level in the reservoir. Look at the carpet in the driver's footwell for fluid from a leaking MC.

WALTSTAR

I pulled the rubber plug at the bellhousing and got about two tablespoons of fluid. I imagine the slave has failed, but I decided to replace both rather than rebuild. Tips on getting the master out, maybe?

karl ruiter

Getting a master back in is a pain. Pretty much as bad as it gets. I have had some luck just replacing the guts of the master. As long as your blue hose is in good shape I would strongly encourage you to try that first. You pull the circlip in the foot well and then pull the guts out. Also, I seem to recall that there is an issue with the masters sometimes, where some version of the master have a shorter throw and do not move as much fluid, so need to be modified to fully disengage on some cars. Its all here on the list somewhere, but for now, be advised that here abide monsters and do your research before you pull the mounting bolts out of that master, especially if it might be good.

Mrmerlin

Time is money...
or so they =say.

I would suggest that you buy a,
New release arm bushing
new master,
New slave,
New blue hose, though now its made from black thread
New Greg brown flex line,this goes from the sway bar mount to the slave. It makes easy work of bleeding the system.
this line will replace the hard line over the starter and the short flex line.

You will have an easier time of things if you remove the DS parcel tray and then loosen the booster bolts.

Following these instruction will increase the chances that the clutch will work well for the next 10 years or more without any other service besides a fluid swap

worf928

worf928

SwayBar

Since it appears the slave cylinder failed, replace it first.

If that solves your problem, you can enjoy/drive the car now, and over winter consider and make the changes mentioned above.

WALTSTAR

If I go in, I'm only trying to do it once per problem. Since the MC is the same age as the SC (original), I could reasonably surmise that the same fate is inevitable.
Karl and Worf, if I buy a new set from 928 Intl' I wont get the full throw is what you're saying?

Mrmerlin

when you get the old MC out you need to take it apart and look at the piston ,
post pictures here for more info.

The new MC has a shorter piston stroke so the tip of the piston must be trimmed off about 4.5 MM,
then the spring must also be trimmed by one wind.

NOTE the new MC should also be taken apart to see what the piston stroke differences are.
Make sure you get the correct slave cylinder and MC parts to start with.
Their are 3 different slave cylinders ,
and possibly 2 or 3 different MC versions.

That said most of the old original hydraulic system parts will have corrosion in the bores and thus the bore will be damaged,

its best to replace the whole system unless you like to do spot repairs as systems fail.

WALTSTAR

Just reading the comments and I certainly will only try to have to do this once for the next coming years.

hacker-pschorr

Try this:
https://rennlist.com/forums/928-foru...he-fender.html

If the cylinder is corroded / pitted (many are) that won't fix it.

That's why I go the rebuild route via White Post - they put in a brass sleeve.

These cars are so old now, I'm done trying to piece these together. This winter I plan to pull the Clutch Master / Slave, brake booster and brake master - have them all rebuilt by White Post Restorations.

With the brake master / booster removed, the clutch master is a piece of cake.

Just in case it hasn't been mentioned already: Need to be 100% sure the blue hose has no "dips" and is only going up. Trapped air in the blue hose...the clutch will never work right.

WALTSTAR

I have the car lifted and see that it wont be the most difficult R & R Ive ever done. The workshop manual recommends a simple pressure bleed. Does this not work? I bled the clutch once before with a syringe from the SC (reverse bleed) until I saw the end of the bubbles from the brake reservoir. Worked great.

karl ruiter

Bleeding can be easy or an adventure. You kind of never know. I use a Motive power bleeder, which works pretty well. Usually. If it does not I use a procedure called 'burping' the master, which is described in detail on here somewhere.

WALTSTAR

Since I intended to bleed the brakes before winter anyway, I removed the brake MC, the booster, and then got to work replacing the clutch MC, SC, and hydraulic lines. I installed the components one at a time (MC, lines, SC). I had to loosen the starter to get the lines in and out as expected, but overall, not a bad job (when you take the easy way out and just take sh t apart). I cant imagine someone pulling the clutch MC up into place with string. I think I have the larger booster because I could not push the old clutch MC out until I loosened the booster. I greased and adjusted the bushings and rods, of course, then filled the brake/clutch reservoir and cracked the clutch bleeder until I got a steady stream and closed it back up. I have used my motive for some years now and will be back out tomorrow to do the pressure bleed and bolt on my G-Force T/A's for a shakedown.