Freakin master cylinder

[400ex]

I thought I would be real nice to my truck yesterday. Went and bought a new master cylinder from Carquest. Supposedly American made by Raybestos.

Got home bench bled and installed it. After about an hour and about a 1 gallon of fluid, I still had no pedal. I tried everything. So in desperation I re-bled the old one and installed it. After 5 minutes of bleeding the system, it held pressure.

Boy was I pissed off big time. New master cylinder and it was faulty -
I assume.

So I guess a remanufactured Japanese unit will be what goes on the truck.

So much for American quality.

Sorry, I'm still pissed.

James

[rage'nrat638]

DOHOOOOOOO
and i thought that stuff only happened to me

[ChrisK10]

Dang... sorry to hear that. I would bet that there is a growing number of people working in the manufacturing sector of the U.S. economy that aren't even American citizens...

[69 Short Fleet]

That's not good. Very Very frustrating!!! Don't worry your not alone stuff goes wrong at times, I had a rubber seal fail on mine 2 weeks after I just had my truck painted, wrecked the whole paintjob under the master cyl on the firewall.

[400ex]

Well at least I'm not alone in dealing with this crap..

69shortfleet - sorry about the paint. Thats really a pisser.

I guess I didnt tell the whole story. Along with the "new" master cylinder, I re-plumbed the front brake lines and added a new proportioning valve from GMCPauls. My service manual said to depress the proportioning valve button on the front of the original valve. I assume this is the same for the new one. My brother and I spent about 2 hours and about 1 gallon of brake fluid trying to bleed it on Monday

Today, Tuesday, I went and bought a reman master cylinder from Oreilly. We spent about an hour tonight trying to bleed it and over 32 oz of brake fluid.

Still a mushy peddle. I'm about ready to park it even after installing a rebuilt rear axle with Eaton posi 2 weeks ago.

Any suggestions appreciated.

James

[69 Short Fleet]

James, is there any evidence of brake fluid leaking anywhere in your brake system? You might want to double check where the lines go into the wheel cylinder and make sure there tight. Did you use new copper washers on the wheel cylinders when you installed the new lines? Are the front brake lines (rubber section) ok? When I bleed my brakes I start with the furthest wheel cylinder (passenger rear) away from the master cyl. and work my way to the closest. I'm not sure about the prop valve (never had to work on mine) Hope this might help.

[400ex]

69shortfleet - After a good cooling off period last night I'll probably do as you said and go back and re-check where the lines connect to the calipers and wheel cylinders and also the compression fitting tee I used to split the front wheels.

Might try and pressure test if I can.

Thats of course after I go and buy more brake fluid and brake cleaner.

If I figure figure anything out, I'll post later...

Thanks,

James

[danho]

This site has some helpful info for brake problems, it might help, it might not. Just in case.
Dan.

http://www.classicperform.com/

[CaperCat]

Grim Reaper has some excellent advice on how to get our brake systems working. Here is the link: http://67-72chevytrucks.com/vboard/s....php3?t=111903

[junkyardjohn]

I Had A Simaler Experiance When I Put Front Brakes On My K5 Blazer. I Bled That Sucker For Half A Day, & Went Thru About 3 Qt.s Of Fluid. I Drove It Around For A Couple Of Weeks With Mushy Brakes. I Finally Replaced The Rears & It Bled & Pumped Up Hard Right Now. The Drums In The Rear Was Oversize & With The Shoes Worn Down The Wheel Cylinders Were Pushing The Shoes Out To Far & Not Letting The Pressure Build Up. Just Something From Another Prospective. John