Brake bleeding drums on C-20

[Happy_dan]

1968 C-20 brake flushing with drum brakes, no power.

I was flushing out the brake fluid (and very glad I did) and all went well for the first 3 wheels. Started on furthest away, passenger rear, then drivers rear and then front passenger. I was able to completely flush the fluid from all of these and boy was it bad!

I was feeling happy and almost done when I got to the front drivers side. I used my pressure bleeder and pumped it up. Opened the bleeder and the ugly fluid started to come out but then stopped right away. Nothing more would come through the line.

I detached it from the hard line and the hardline drained freely.



I do not know a lot about the old drum brakes but these are very clean and in good shape. Obviously there is an issue after the hardline and my first inclination is the rubber hose is collapsed or clogged but I hesitate because I would think I would still get something out of it.

My question is what do you think would cause me to get nothing out at all. Collapsed rubber line? Bleeder clogged? Something with the wheel cylinder?

My plan is to pull the bleeder off and make sure it is clean and not clogged. Then pull the rubber line off (already ordered a new one) and see if it's clogged or will pass any fluid. Last and least desireable is to get a new brake cylinder. I don't want to have to take this apart because it looks so good. No leaks and clean.

That is my plan but would love any thoughts or opinions from the experts.

By the way, I did read other threads and what I did for my Motive pressuire bleeder and manual brakes was to machine out pockets for the two bolts in the firewall so the adapter fits better over the reservoir. Works perfectly. (I can get a picture of that if anyone is interested.

Thanks in advance.

This is just to show how good condition the brake setup looks. The other side is the same.

[rpmerf]

Either the rubber, or some gunk got in there. I would certainly do both (if not all 3) rubber lines. If one goes bad, typically the other isn't far behind.

Could take it one step at a time. Pull the rubber hose off of the wheel cylinder. If that works, the wheel cylinder is clogged. If not, the hose is bad. Certainly pull the bleeder completely out and make sure it is clear.

[kwmech]

See if you can bleed the rear again to recenter the balance/proportioning valve. After the gunk went through it probably loosened up the valve in there where it would work again. Bleed it slower

[68Gold/white]

First, if you are ordering A front brake hose, and plan to install it, ORDER BOTH front hoses, to be safe...

If you are having to do this yourself, slightly open the clogged bleeder, get inside and push the pedal. Not extremely hard and not for long, this may allow the fluid to flow freely, if clogged. Then try to bleed it as you were before.

Even if this works, I'd replace BOTH front hoses

[Happy_dan]

Thank you all!! I will replace both front hoses even if that is not it.

[toolboxchev]

I had brake issues on the same setup 14 years ago. Bought new wheel cylinders and everything for the brakes.

Compared to the trouble they will keep you out of, its cheap, IMHO.

With BFG AT tires and that exact setup, I can stop on a dime, especially partially or fully unloaded.

[palallin]

I hope changing the hoses is easier on your 3/4 ton that it was on my 1/2 ton. The job NEEDS to be done, but plan for longer than you believe it will take, and store up a good stock of cuss words. . . .

[rpmerf]

Originally Posted by palallin

I hope changing the hoses is easier on your 3/4 ton that it was on my 1/2 ton. The job NEEDS to be done, but plan for longer than you believe it will take, and store up a good stock of cuss words. . . .

It's not. I have a 3/8" wrench that's been grinded and bent to get that hose on the wheel cylinder.

[Happy_dan]

Originally Posted by rpmerf

It's not. I have a 3/8" wrench that's been grinded and bent to get that hose on the wheel cylinder.

Do you have a picture of the wrench? Is it because you can't get the wrench on it? I was surprised at how the bleeder was right against the brake line too. You can't even use a fitting wrench because you can't get it around the bleeder because the brake line is in the way. Who designs things this way? Of course it was 1968 but still.....

[palallin]

Originally Posted by rpmerf

It's not. I have a 3/8" wrench that's been grinded and bent to get that hose on the wheel cylinder.

My problem wasn't on the cylinder but the fitting at the frame.

[Happy_dan]

It was the bleeder but I suspect I will be replacing brake lines before too long.

Hoping to get through this summer of driving it then pulling motor and trans next winter to fix oil leaks. I will have a very focused list of things to do so I can prevent project creep. Brake lines and hoses will be one because of how much rust I saw when flushing

[rpmerf]

I'll try to get a pic. Nothing really special. Took a but off the fat side of the open end, and bent the open end in a bit. Not sure if there is a better way to get at it. Might be easier to remove the wheel cylinder, install the hose, and reinstall the wheel cylinder. I think it was really close the the knuckle.