CLutch Master Cylinder... fun! (long)

[curt_924]

Hi all,

Well I'd been procrastinating.. hesitating.. about replacing the clutch master cylinder in my 79', largely because everyone says its such a pain in the a$$ to replace it. Last saturday I decided to replace it and I can be one more person to confirm that. It is a pain in the a$$ to replace it. Thought about just switching out the cylinder.. but couldn't live with myself if I did.. so replaced the whold kit and caboodle. In brief for any brave soul attempting such a task with time on their hands..
1) loostened the cylinder from the pedal. (yes the stupid little metal attachment pulls out of the cylinder) AND loosened the two bolts holding it in. Be careful.. the clutch pedal will **THUNK*** move forward to the firewall and get your hand if you move it forward due to spring action.
2) loosed the brake booster in the car from the firewall. (removed screws from inside on firewall... also disconnected from brake pedal)
3) removed brake reservoir with fluid getting everywhere. (to make room)
4) removed brake master cylinder.. then realized I have to get another just for preventative rationale.. heck I've gone this far why not! (to make room)
5) removed brake proportioning valves (thingys below the brake master cylinder) (to make room)
6) did a contortionist thingy with my left then right.. then left hand to loosen the brake line from the clutch cylinder. Then thanked God profusely when the brake line fitting did not strip. Continued to contort to get the fitting off.
7) Got stupid fitting off and smiled for first time in hours. Removed bolts from clutch cylinder and pulled out from under brake booster
8) thought what the heck and tried to get brake boster out before realizing is well.... impossible. and wondered how on earth they got it in there in the first place.
9) went inside and relaxed for a couple days. Contemplated: what exactly WERE the engineers thinking when they did this?
10) took new master cylinder and tied string to the tip and tried to pull through hole. Tip came off and said some not so nice things. The put straightened wire hanger through bolt opening in bulkhead and through corresponding hole in clutch cylinder. Pushed along wire to get into position. bolted into place with one bolt loosely.
11) Contorted hand to fit line fitting onto end of clutch cylinder. Tightened, bolted rest of clutch fittings together and assembled back onto pedal. tested cylinder for leaks with brake fluid.
12) reassembled brake booster by bolting it to firewall. Pedal.
13) put back proportioning valves and then master cylinder. Put back vacumme tubes and look forward to bleeding everything (tomorrow)
14) yippy skippy. Conclusion: They did this as punishment for Stalingrad.
It is a pain. But can be done. Usual 928 repair.. complex, arduous and need to take 5 other things out to get 1 thing in.

[rhjames]

didn't get thru the whole post, but I did the same thing back in January----

complete clutch hydraulic system replacement. replaced everything, it's the only way to do it.....

--Russ

[Fabio421]

Just wait until you try to bleed it. The fun starts all over again. Do yourself a favor and buy a Motive Power Bleeder now. I have never had so much trouble bleeding a car as I did with the 928. Once I hooked up the power bleeder I was done in minutes. Its a wondrous thing.

[rhjames]

I'll second Fab's bleeder advice-----it took minutes to do the entire system.

Motive Power Bleeder----worth every penny you spend on it.

while you're at it, put the blue stuff in it.

---Russ

[Danglerb]

Sure looks like a bug sprayer, how is it different?

[rhjames]

D---

fill Motive Power bleeder with about a quart of brake fluid.

attach the end with the brake master cyl cap on the master cyl.

pump up pressure to at least 10 psi.

open bleeder on brake wheel cyl or clutch cyl and let fluid (dirty fluid/air/etc) out until steady stream of clean fluid appears.

close cyl bleeder.

do the same for remaining cyl bleeders.

less than 30 minutes to do a whole car.


---Russ

[Danglerb]

Do you leave the brake fluid in the bug sprayer, er Motive Power Bleeder between uses?

I've seen some comments about it being a pain to clean and people just using it for pressure and refilling the reservoir manually.

[Fabio421]

I leave the fluid in it. If it doesn't hurt our plastic master cylinder resevoirs it should be OK in the power bleeder. At least I hope so. I never read the directions. Directions are for after you can't figure something out and it sits broken in front of you. Thats usually when I think to read directions. LOL

If you go with the power bleeder I would like to add something. Russ said "pump it up to at least 10 psi". I respectfully disagree. Most times you can get the job done at a slightly lower pressure. This is a small point, but if you blow off the blue hose you are going to want to slit your wrists. I always use as little pressure as will do the job. 6 or 7 psi will usually do it. 10 psi most likely wont blow off the blue hose, I just want you to realize that you must be cautious of this potential problem.

Good luck

[Danglerb]

Brake fluid can absorb moisture, so that would be a concern in the bug sprayer more than a small metal can. I haven't decided if I will get one, or make something. I have kind of an itch to put in the Gstop brake lines.