Update on ZF reverse

[Cigarman]

Those of you who prowl this forum are probably sitting on pins and needles to find out what the next chapter is in my comments about difficulty to shift into reverse/low clutch fluid.

One of the sources I went to is the Corvette Doctor http://www.corvettedoctor.com .

I received an e-mail from Chris and he added the following after I told him of adding clutch fluid:

**************
Check the inside of the car where the clutch rod goes to the pedal and see if you feel wetness at the firewall. If you do you will have to replace the clutch master cylinder. You may also have to replace the clutch if the master is leaking. To much pressure is being applied to move the clutch fork because the clutch might be to the end of it's life. Give it a check, if you find no leak you should be alright.

****************

Well, I checked and it is wet. Looks like I at least need a master cylinder for the clutch.

 

[Rob]

Glad you found out what the problem was. Are you going to do the work yourself, or bring it to someone?

 

[Cigarman]

I gave up mechanical work a long time ago. Looks like the dealership is going to get some more business from me. I don't really trust anyone locally yet.

I have to get involved with a local club, I'm joining Central PA Corvette Club. I hope that I'll make some contacts there to find a place that is good and reasonable also.

Maybe I'll post an inquiry on the forum to get some other sudggestions

 

[69MyWay]

Glad you found it. I really doubt you have a clutch problem based upon the low miles on the car.

It is common for seals to fail and fluid to go bad over time. I had a sweet 86 rag top with low miles. It had a bad rear main seal, bad trans seal, and bad valve seals. Not from being worn out, but from sitting up and drying out.

Sounds like you will be up and running in no time.

 

[Cigarman]

Yes, the low miles have the advantage of low parts wear, but cars are meant to be driven. I had to replace the intake seal after I drove the car about 300 miles. These seals do not usually go until the car has 60k+ miles. As you say, the seals tend to dry and fail after storage.

I need to have all of the fluids changed. I only got to oil and coolant prior to the winter, and have been riving it on warm weekends enough to keep the battery charged.

Problem is that the car was in storage the last 2 years 17 mi last year and 45 the year before. It looks like it came right off the showroom cloor and I guess a lille work will get it back in perfect condition.

 

[David-F]

Very common problem and age has as much to do with it as mileage, not that hard of a job to do but you will spend some time on your back releasing the rod from the pedal. They will self bleed but will take a lot of pumping. The fact that you were probably able to just top off the fluid and get the pedal to work pretty qiuch is a good indacation of a master leaking, if it had been a slave it would have taken a bit of pumping after topping if off to get it working correctly.

David Fulcher

 

[Cigarman]

I'm having the master cylinder looked at and replaced tomorrow. I am thinking of having them replace the fluid, change the trans, and the rear end. What do you think?

Necessary or overkill?

 

[69MyWay]

Good idea. Not to mention it will already be at the shop. These are fluids you won't have to worry about again for a long time. It is quite possible they have never been changed.

 

[Cigarman]

Yeah, I've hardly had time to take my Lady out and she is in need of all of this inaddition to the usual TLC. I bought her to be a Sunny Sunday ride, but lately I'm realizing that it will be tough to control myself--particularly when I see that no driving seems to have a worse effect than moderate mileage...

 

[vettepilot]

Cigarman,
While you are looking at replacing the clutch master cylinder, you might also want to check your brake master cylinder. Noticing the age of your car, and the aluminum master cylinder construction, you may be replacing that soon. The inside has a tendency to corrode due to the moisture that brake fluid draws in from the atmosphere, then the rough bore tends to destroy the piston seals, and then leakage occurs, then it's replacement time. Same thing happens to the two clutch cylinders, master and slave.
Hope all goes well for you.
Vettepilot

 

[vetsvette]

I agree with Vettepilot. Even if the brake master is still good you want to change your brake fluid. This stuff is like a sponge, it will draw moisture right out of the air and then corode your system from the inside. Good luck.

 

[Cigarman]

Thanks. I just got a call from the Chevy garage and they told me there is no sign of clutch master or slave leak, but that the caps had been removed or loosened at some point and that fluid had leaked over and down the firewall. They are cleaning it well and then checking for leaks. They haven't ruled out a bad master, but doubt that it is the problem.

Strange, isn't it?

 

[vettepilot]

Sounds like you found a good dealer with a reputable service department. I really think that the greatest percentage are.
Maybe all that needs to be accomplished is bleeding, if the caps had been off already, and fluid possibly added, there could be some air still in the line to the slave cylinder, of course this would make the hydraulic system less than efficient because of the compressibility of any trapped air in the fluid. Keep us posted.

 

[Burnnrubber]

Check Out This Site

Anyone interested in the 6 speed ZF trans & the Hyd clutch. should go to this site & read up. Best Info I have found on the subject.

www.ZFDoc.com

 

[Cigarman]

Yeah--great site. I went on there the other day and printed a copy for the mechanic at the Gm garage. he wsa very appreciateive--told me that this info was clearer than the info provided to them by GM.

By the way,

They cleaned around the master and slave clutch cylinders, bled it and could not get it to leak. Apparently it was the fact that someone unscrewed the caps and they leaked all over the firewall befor they were replaced--and then noone topped off the resevoir.

They charged me 30 min of labor for the job (they also changed fluids and the rear end on that day so they made a few bucks on the deal).

The car shifts like a hot knife through butter. Took it for a 50 mi spin with the top down and the heater up. Got some sun on my face--Life is good.