Chevelle Brake Problem

[Postsedan]

I bet it`s the Master Cylinder from Ground Up....I had heard they had a bad batch :-(
I would do what Phil said.

Dan

[earntaz]

Now you all understand why there are destruct buttons on missiles ... no matter how much $$ it may be worth, something can go terribly, terribly wrong. TAZ

[Damien]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Woj</div><div class="ubbcode-body">FWIW,

I used a repop master cylinder on a past 69 Chevelle project, bench bled the heck out of it and never got a pedal. Put a rebuilt on in, bench bled and it worked like a champ. There is a chance you might just have a bad MC. Try another from a parts store (they are cheap). Or, maybe your old one if it worked.

Good luck.

Phil Woj. </div></div>

Unfortunately Phil, the nearest parts store for another is about 8,000 miles away. [img]<<GRAEMLIN_URL>>/smile.gif[/img]
I'm going to grease the end of the pin and connect everything back up and see if the pin bottoms out on the master. If not I will put the old master back on and see if that works.

[Postsedan]

Best of luck Damien.....hang in there [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Dan

[PeteLeathersac]

Obviously you've cleaned and serviced everything, LH/RH adjusters also longer shoes all correctly placed plus emergency cables free and released...wind out rear adjusters 'til you can just get the drums on but not dragging when fully in place and rotated.
When all else was correct and new masters seemed to be at fault, we used to give them a few hits w/ a hammer while someone else pumping...sounds dumb &amp; not what you'd want to do to resto cars now but it often made wonky masters come around also stay Ok after you got good pedal.
Good luck!
[img]<<GRAEMLIN_URL>>/beers.gif[/img]
~ Pete

[Damien]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Postsedan</div><div class="ubbcode-body">Best of luck Damien.....hang in there [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Dan </div></div>

Well, we got it in the end and as usual the culprit was the repro product. The factory pin that came with the booster was bottoming out on the master piston. Obviously the hole in the master was not quite deep enough and was hanging it open.



I took off about 3/16 in a couple of goes, reinstalled it and we now have a hard pedal. Probably the last straw for the repro stuff for me, I have been bitten before and this is about the end of it, wherever possible. Thanks to all that offered assistance.

[Postsedan]

Well done my friend....I feel your pain.

Dan

[njsteve]

I had a weird problem with my survivor 73 Firebird. It sat for 41 years with the original brake fluid which ate up the inside of the master cylinder bore. I sent the master cyl out to White Post and they sleeved it. When I reinstalled it, the pedal would slowly bleed down to half way and then would be firm. Very weird. I swapped out the sleeved master with a known good one and the same thing would happen. Turns out it was the rear wheel cylinders which had corroded internally and would engage, but would not pull back once engaged due to crud in the bores. Once I swapped them out, all was well.

[Zman1969]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Damien</div><div class="ubbcode-body"> Well, we got it in the end and as usual the culprit was the repro product. The factory pin that came with the booster was bottoming out on the master piston. Obviously the hole in the master was not quite deep enough and was hanging it open.
I took off about 3/16 in a couple of goes, reinstalled it and we now have a hard pedal. Probably the last straw for the repro stuff for me, I have been bitten before and this is about the end of it, wherever possible. Thanks to all that offered assistance. </div></div>
Damien Whew!!! thats good news I was wondering if it was a southern hemisphere toilet swirls backward Yankee thingey issue going on there
repop parts IMO is first thing to suspect!

[Mr. Chevy]

Just food for thought, I have had NOTHING BUT HEADACHES with Repop brake parts, ie. boosters and master cylinders, over the years causing all kinds of weird things from improper brake pedal travel to the front brake pads being slightly compressed on the front rotors causing drag and excessive heat when your foot is entirely off the brake pedal!! In my opinion it's best to restore and put the factory stuff back on...

It's also a good idea to switch the system to silicone brake fluid for rust issues. Once that is done you can literally park the car forever and not worry about the system locking up on you... Plus if you spill it on a painted surface it won't harm anything, just wipe it up...

Rich