Slave cylinder day.

[rhipsher]

Well I have less than 8,000 miles on my slave cylinder after installing a new clutch a year ago and today it bought the farm. I guess it could have been the valve being installed backward like I have read about on here that causes them to prematurely fail. I have noticed that in that time that clutch fluid had been leaking out. And I have had to refill the reservour 3 or four times. Time to get dirty again and feel my skin burn from that clutch fluid. Wahoo!

[jonszr1]

bummer ,hope you get one done right this time . how can one ck the slave before putting it in to see if its right

[rhipsher]

I guess you have to pull it apart and compare it to the picture on this forum. But if you don't take it apart correctly you can destroy it. They are about $85.00 so I'll take my chances and just install the new one. If I only get 8,000 miles out of it because of bad bendix assy job then so be it. It only takes an hour to install it. The only bad part about it is if it goes cocka on you, you'd better hope your not far from home and that there are not to many lights you have to stop at.

[lbszr]

Originally Posted by rhipsher

I guess you have to pull it apart and compare it to the picture on this forum. But if you don't take it apart correctly you can destroy it. They are about $85.00 so I'll take my chances and just install the new one. If I only get 8,000 miles out of it because of bad bendix assy job then so be it. It only takes an hour to install it. The only bad part about it is if it goes cocka on you, you'd better hope your not far from home and that there are not to many lights you have to stop at.

First one I bought had the seal installed right, but 1/3 of the seal was ripped off from installation. They come apart easy, used a dull tiny screwdriver to work the lip of the seal in with constant pressure pushing on pistion, but not much pushing and when it's ready it pops together without forcing. Cleaned up the chamfered edges of the cyl. first, they were kinda rough.

You could practice on your defective one first.

[tomtom72]

Man I remember the bad ones. Go to zfdoc.com and/or our zr1netreg site to get the skinny. The seal on backwards was not the only defect on the DOM type slaves cylinders.

seal on backwards.
bad welds @ the line bungs.
various porosity issues with the metal.
Bore run out.
lousey machining of the ends of the springs. The spring end is machined flat and they never chamfered the ground ends, so they broke off after a few cycles.
General metal fragments left behind, Bill felt they came from the tapping of the bungs.

Back in late 05 & early 06 I went thru six sets of masters & slaves before I got one slave to work. Some of the masters had badly formed reserviors, porosity, weld, & metal shavings issues also. I was doing my r&r at the height of the "spillage" issues, so it was a real crap shoot on the parts. I finally had to assemble a slave from parts scavanged from other new deffective slaves and a cast type cylinder. Quality control.

I would suggest if you continue to have trouble to call Bill at zfdoc. For me, that was the most expensive "cheap" thing that I did to my Z.


Tom

[QB93Z]

Is there a sure way to get a good slave cylinder today? I replaced mine in December and it is leaking worse that before already.

Is there a best brand?

Is DOM (drawn over mandrel, I believe) more or less likely to leak than cast?

Is there a GM version that works correctly?

What is the story today?

Jim

[Jagdpanzer]

Mine was leaking a bit when I first got the car back in April of 07.
Last September I finally tore it down. Found the typical swamp gue that develops in the cylinder after all the years. Everything looked in good condition, including the seal, after thorough cleaning. So I polished up the cylinder, reassembled it with the old seal and so far it hasn't leaked a drop since (knock on wood). However, I do have a new slave cylinder standing by should my luck change.

[Jagdpanzer]

Originally Posted by QB93Z

Is there a sure way to get a good slave cylinder today? I replaced mine in December and it is leaking worse that before already.

Is there a best brand?

Is DOM (drawn over mandrel, I believe) more or less likely to leak than cast?

Is there a GM version that works correctly?

What is the story today?

Jim

Jim,
I think the original GM DOM types are perfectly okay if they were assembled correctly with a good seal when initially manufactured. However, given all the bad luck we have had recently with the quality of replacement slaves, regardless of where they came from, I would not put a new one in unless it was first disassembled and thoroughly inspected. The time it take to do this extra step possibly saves having to deal with the problem again a few months down the road.

[tomtom72]

Jim,

My other post has most of the defects in the both parts. ZFdoc.com has the full story on the defects. The pictures he has come from some of my deffective parts that I sent in for autopsy to help our situation. Bill put the call out.

There was a move by Bill and Tom Henry Chevy (Bill's parts supplier) to hold GM's & TRW's feet to the fire on this issue. There were some promises made by GM & TRW, but I do not know what the final resolution was. There was a time period when all of the C4 hyd parts were withdrawn, I think, from stock. Anyway back in 06 there were parts in the system, and then there were no parts in the system. I believe it took about 3 to 6 months to refill the system with "new parts"(?).

I do not know if what I did to solve my individual issue as I was right at the height of the bad parts. I actually bought a cast slave cylinder, Fedral Mogul unit. The mting flange looked to be too thick to leave enough threads on the B/H bolts to get a good grip. I took the guts out of the F-M cast slave and transplanted those guts into the best DOM slave body that I had out of six. The F-M guts had a better seal in MHO. Their seal was more mushroom like, broad shoulders, same height, and no micro-ridges. I think that he broader shoulders were F-M's answer to the torn micro-ridge issues. Anyway, I did the transplant and mid 06 have had no issues....except I lost one other master due to bad porosity and bad bore run out.

The Fedral Mogul cast slave P/N is F120165.

I reused a bad slave DOM body with the following preperation:

1.) Honed the bore with the finest wheel cylinder stones. (remember wheel cylinders?) Not many passes & slow speed on my Ryobi 18v drill w a run down battery. I did the hone after doing a bench test on the bore to establish if the bore was truer than the others I had in stock. All my bores had varying levels of concentric & long axis scoring, proly from all the metal they left in there & me bleeding the part.

2.) I used 600 wet soaked in GM clutch fluid to work the snap-ring landing ridges to a chamfer.

3.) I "bule printed" () a DOM spring by using a fine file to work the flattened spring ends. The factory just hit the spring ends with a grinder to flatten them so the spring would not rock under pressure ( my assumption?). They just left the ground ends. I worked to chamfer the edges with the file.

4.) I made sure I got all the metal that the factroy left in the finished part out of the bore. Broken spring ends & the results of cutting threads in the bungs.

5.) Bench bleeding the master and slave prior to install. This was easy for me as I had soooo many spares.

6.) Install and use phoenix gun to do reverse bleed as the final bleed. Yea I bought one because the wisdom at the time was that the parts were good, the issue was really that none of us C4 owners could do a simple bleed!

If I can be of any help just hit me up. I do hope that the new batch of parts is better than what we went thru back in 04 to 05.

Tom

Bill will sell or fix your new slave, just ask him.

[QB93Z]

Phil and Tom,

Thanks for the information.

I guess I will install the newest replacement I bought and start the clock on how long it lasts.

I now have a couple of "spare" slaves to fiddle with. They are all the cast body units. I will take one apart and try to rebuild it as a research/learning project. I will ask again if I need any help.

Jim