Seriously bummed;New brakes don't work

[WorkinLonghorn]

I've been sucessfully doing my own brake jobs on my fleet of junk since I was a kid.
On my '69 GMC with Dana 60 rear I started getting stuck right rear brakes. I looked and both sides were soaked in fluid/oil. The drums were pretty shot too so I got new wheel cylinders,new drums,new oil seal (left side),new hardware kits,new shoes.
Put everything on and test drove it and the right rear locks up WAY too soon! Plus it drags even with the adjuster backed off. Drum turned blue from the heat. Took it off and found the seal leaking so replaced it and the oily shoes and scrubbed the blue drum with sandpaper. Still locks up REAL easy and still drags.Oil still leaking past the seal and today I noticed the fluid was way down in the MC.
This really sucks bad. I do have a simple question though.

Is it possible that the two top springs interchangeable or does one color go in front and the other in back? That's the only thing I can think of unless there is a 3/4 ton kit and a 1/2 ton kit and they sold me the wrong ones.Or the cylinder is a larger diameter (for the fronts???).

As for the seals still leaking,the seal surface looks good.Maybe the wrong seal?
I'm too bummed to even lookat the right side. Here's what I found after first set of shoes without replacing the seal;

[mclairmo]

Clearly, the shoes are not retracting. Either you have a mechanical problem preventing the shoes from retracting or a hydraulic issue. As for mechanical, be sure that you have the correct adjuster and that the drum slides on easily with no major resistance and make sure the drum turns freely with the brakes not applied. Also, make sure the metal pads on the backing plate where the shoes slide are not grooved and have been greased. Grooves in those pads can prevent the shoes from retracting. Make sure you have all the correct springs that are needed to make those shoes retract. As for hydraulic, make sure you do NOT have an aftermarket residual valve installed in the line going to the rear brakes. You clearly don't need it. Also, make sure the rear rubber brake hose is not kinked or twisted. If it is, it will act like a one way check valve, allowing fluid to flow to the rear cylinders, but not allowing the fluid to flow out of the cylinders and back into the master when you let go of the brakes.

[WorkinLonghorn]

OK thanks. The brakes worked fine before until the leakage onto the shoes.
The backing plate pads looked good and I greased them,I will look again for grooves.
When I put on the drum it was a loose fit and I adjusted the little adjuster wheel until very slight drag was felt. Later I backed it off some more but it still drags when driving.I do notice that when I quickly apply the brakes there is initial resistence and then the brakes apply,maybe 1/2 second for the brakes to apply,which makes me believe there is an obstruction in the line somewhere,but they never seemed to drag before.
So maybe that is what area i need to look at.
Then there's the leaking seals. I've already ruined two sets of shoes.


Also ,see how the right cylinder rod is cocked up a bit? That doesn't look right and I think that is maybe causing the non-retraction.

[WorkinLonghorn]

Here's a pic of the seal surface;

[sleepertruck72]

Workinglonghorn,
Thanks to your eagle eye, my brakes were properly installed. Here are my brake pics of the same Dana 60 rear axle.
It seems you have the right springs. It does seem in the picture like the rubber seal on the wheel cylinder is not fastened. The wheel cylinder should be 1 1/8" bore for the rear wheel. I think half tons get 1" bore. Good luck with the brakes !

[sleepertruck72]

Workinglonghorn,

The wheel cylinder does look a little cockeyed, The oil seal seems a little different than the one I used. May just be different manufacturer, but mine had a green plastic ? ring on the outside of the seal. The seal surface looks good I would say... maybe the wheel cylinder needs to be tweeked a little bit on the backside in order to mount properly.

http://www.67-72chevytrucks.com/vboa...d.php?t=344112

[mclairmo]

I don't think the cylinder rod being cocked would cause your issue. It is a loose fit anyway. Also, the rubber boot on the wheel cylinder is just a dust seal. Seal surface looks ok. Not sure if this is smart to do but I once sprayed brake fluid soaked brake pads with brake cleaner and just reused them. They worked fine. Just thinking aloud, but could the E-Brake cause this kinda problem?

[Classic Heartbeat]

This might be a stupid question on my part, but did you collapce the wheel cylinders once you installed them? I can see that the rubber dust boot is off on one side of the wheel cylinder. WES

[WorkinLonghorn]

Thanks guys. Yes the dust boot was ajar because I had just checked in there for any wetness.
I'm thinking the seal was wrong because before installing it in the hub I checked it and it was just barely making contact with the surface,but I thought maybe it was supposed to be like that,and the fit in the hub when I drove it home was perfect.
I don't really know what to do. I can't even drive it like this because nearly every time I have to stop I have to go real easy or it skids my $200 apiece new tires!
Yeah I collaped the cylinder but if I remember correctly it pushed back out when I did this and I actually had to loosen the bleeder to install things. I thought that was a little weird but it's been a coons age since I did this on this truck. (coon's age= 13 years).

[mclairmo]

I don't think that's right that the wheel cylinder pistons pushed back out a lot on their own after you pushed them in by hand. You should not have to loosen the bleeder to install everything. I have seen a situation where the brake pedal push rod was not adjusted correctly and it was slightly pushing on the master cylinder piston and caused the brakes to lock up. Have you checked the push rod length to make sure it is not too long? Maybe rear brake hose is kinked? Maybe the factory rear proportioning valve is busted and letting full pressure go to the back brakes? The rear brakes need to have much less pressure since they do much less braking than the front. If you have too much pressure to the rear, they will lock up before the fronts even have a chance to do their job. I have an adjustable proportioning valve to the rear drum brakes on my Camaro and I had to reduce the pressure a lot.

[WorkinLonghorn]

I don't think that's right that the wheel cylinder pistons pushed back out a lot on their own after you pushed them in by hand. You should not have to loosen the bleeder to install everything.

I think you're right. I'm going to investigate the causes of this when I get up the energy to go back out to this mess.
As far as the brake MC rod,it worked fine before. But then I don't know how long I've been driving with wet brake shoes!
Thanks for the advice. This project is driving me nuts.

[70clone]

by chance are the lines on the rearend rubber if so i bet you have a collapsed line causeing the cylinder to stay open alowing the fluid to the wheel cylinder but not away from it

[WorkinLonghorn]

Thanks,I'll check that out.
Then I also have to figure out why that wheel locks up REAL easy.

[mclairmo]

Originally Posted by WorkinLonghorn

Thanks,I'll check that out.
Then I also have to figure out why that wheel locks up REAL easy.

A collapsed or kinked rear rubber hose, as I mentioned above, may cause the rear brakes to lock up real easy because a collapsed/kinked hose acts like a one way residual/check valve and won't let the shoes retract at all, causing your rubbing issue and making it so that the moment you touch the brake pedal, the shoes catch real easy. The shoes are supposed to travel some distance before contacting the drums and rear drums are supposed to have much less pressure than the fronts.

[70clone]

Originally Posted by WorkinLonghorn

Thanks,I'll check that out.
Then I also have to figure out why that wheel locks up REAL easy.

the best way to check for a bad haose is to pump up the brakes till they are locked then go to the hose and disconnect the rubber hose not from the wheel cylinder but the other end where it attaches to the steel brake line. if your brakes become unlocked then the hose is good if it doesnt the you have a bad hose .

[WorkinLonghorn]

Good idea. There is a rubber hose from the frame to the axle where it is again steel and splits off. Probably wouldn't hurt to replace the rubber hose in any case,even though it has only been in service for 40 years.

[vectorit]

I just replaced my rear rubber brake line, and I'm glad I did since it was completely rotten.

I am doing the front hoses as well, and found that no one I checked with carried em. Had to have em custom made yesterday...

[mclairmo]

I replaced all 3 of my hoses and discovered they were hard as rocks and that one was almost split open. My rule is that anything rubber on a 40 year old vehicle is junk and needs to be replaced. Even with low miles, after so many years, rubber petrifies. I put new hoses and belts on my Camaro 15 years ago and just had to replace them all again since they were getting rotten and dried out. Used braided stainless brake hoses so they are still ok for now.