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 There was a time period when all of the C4 hyd parts were withdrawn, I think, from stock.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.