junk master cylinders

[Gene M.]

I've been thru 3 master cylinders in the last week. All three were GM castings. Two rebuilts and a new Delco. The Delco was made in china, no wonder it was junk. All three would bench bleed the front cylinder with good pressure. The rears were dead as in no pressure, no air, no fluid. The only way I could get fluid to pass was via vacuum using the Mighty Might vacuum pump. But still no action/pressure from the piston.

This is a 1" bore for a non power brake '72. Only one rebuild had bleeder screws.

Anybody found a good replacement master cylinder? It does not have to be for flight judging just functional.

[Dale S.]

Re: junk master cylinders

I sold Wagner brake for years never had a problem( other than incorrect installation), I dont know if they are still in business. Cardone also had a good product. (Auto Zone), NAPA also sold quality parts( If quality parts are still made). Dale

[Gerard F.]

Re: junk master cylinders

Gene,

I thought I had pretty good luck with Corvette Stainless Steel Brakes master cylinder for my 67. Works just fine and not many could tell the difference at judging. It had the correct 67 wording on the cap.

Not sure where it is made.

Here is their website:

http://www.cssbinc.com/1953-1982newdelcomastercylinders.aspx

[Patrick H.]

Re: junk master cylinders

I bought a new "Fenco" brand for my Cutlass a couple of years ago through AutoZone. Turns out the rear of the piston was machined incorrectly, and the depression in the rear of it was not deep enough. My problems mimicked yours. So, I returned it and bought a new ACDelco. Ironically enough it was a reboxed Fenco, but at least it fit without any problems.

Just a suggestion as to "why."

Bendix or Wagner are likely your best bets.
Or, if you find a rebuilt one, getting one that has the bleeders. My locally owned store will let me look in the box before I take one home - did that with the 71 Corvette several years ago.

Patrick

[Harmon C.]

Re: junk master cylinders

At the point you say three rebuilds are all junk I would check out the lines hoses and rear calipers. I have been down the same road you are going and then the rears like magic start to work and I never know for sure why and I question why it takes three master cylinders to get the job done. Corvette brakes are the worst job on the car for me and I have the motive bleeder which has helped but they are a bitch.

[Gene M.]

Re: junk master cylinders

Lyle, Dale,
These master cylinders were exhibiting problems with the rear piston when bench bleeding. No pressure in the rear section. Cardone was one of the rebuilds. Auto zone the other. The new Delco (china made) was thru internet since no new units were in my area.

Jerry,
Did you have any problems bench bleeding the SS Brake master cylinder?

Thank you for suggestions, I hope at $140 the SSB unit is made in USA. Does any body know where it's made.? I want to stay away from china stuff.......

[Patrick H.]

Re: junk master cylinders

Thank you for suggestions, I hope at $140 the SSB unit is made in USA. Does any body know where it's made.? I want to stay away from china stuff.......

Remember, it's likely the guy in the US who spec'ed the unit that is at fault, not the guy in China building it that caused the problem.

Another discussion for another day...

Patrick

[Harmon C.]

Re: junk master cylinders

I can tell you that SS sleeved M/C's usally have a hole that is not drilled and won't gravity bleed at all. When you bench bleed would no fluid or bubbles come out of the rear port or do you have some gauge to measure pressure hooked up?The Autozone parts are SS sleeved as I have used their rebuilt parts and even found some of their stock to have bleeders a few years ago.

[Gene M.]

Re: junk master cylinders

Patrick,
That is entirely possible. But I want to support USA workers, after all I'm an AMERICAN. I have no interest is supporting china. I'll try and seek one of the American rebuilders you suggested.
thank you

[Gene M.]

Re: junk master cylinders

Lyle,
Initial fluid in casting bubbles just come up but slowly. But the fronts were pushing and moving fluid once air was out. Rears did not push air nor fluid. I even sucked the air out that would never stop with Mighty Might. No rear piston pressure even plugging the fitting port.

[Gerard F.]

Re: junk master cylinders

Gene,

I had mine put on at my trusted brake shop about three years ago and I don't think my mechanic had any trouble bleeding the M/C. He has been doing brakes for at least the last 30 years. (Same mechanic who put my new trailing arms on in my backyard, last fall)

The manual brakes have worked great for the last three years. When we removed the rear calipers for the trailing arms last fall, reinstallation of the calipers and bleeding of the rear was a snap, I sat in the car stepping on the brake pedal to his instructions, and using not special equipment, we were done in 5 minutes.

Take a look at the background of CSSB on that website, they have been into Corvette brakes a long time.

Cheers,