The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Bleeding Brakes - 1964 K10 - help please

I'm really stuck and hoping someone has some insight to share.... there is a drum brake on each wheel. I replaced the rear soft and hard brake lines. Prior to replacement, the brakes worked fine. Now that the new lines are in place, I cannot get any fluid to the rear lines. When trying to bleed the brakes, no fluid is getting to the rear lines. When I open the rear bleeder on the master cylinder nothing comes out either. When I put my finger over the hole in the rear well on the cylinder and pump the brakes i get suction. I was able to force fluid thru the line and it bleed out of the bleeders. There is no pressure on the on the pedal.

I dont know what to do next. Any thoughts or suggestions?

sounds like your master needs replaced,
Scott

Sounds like you still have air in the lines.

i'm hoping its not the master cylinder. Would the master stop working when it was working just fine prior to the lines being replaced? I only replaced the rear line from the frame to the wheels.

Any thoughts on how to get the air out of the lines? I was bleeding them correctly. When I put the oil in the cylinder it didn't go done the line at all. But also the bleeder on the cylinder wasn't bleeding when I pumped the brake either.

tell us how you are bleeding them. the exact procedure that you are using
ron

Sometimes, when you push the piston outside of it's normal travel range, crud, scratches or ridges within the master will damage the seals.
Scott

How true that is! And depending on how the lines were run it becomes almost impossible to get the air out with just the volume of oil created by using the master cylinder. I always hook a vacuum up to the bleeder an suck the air out and oil through the lines. Then finish with just a couple pumps…….

i started by making sure all of the connections where tight and secure. i put oil in the master. Then started with the rear drivers side tire and opened the bleeder. I then pumped the brake pedal. I might have pushed the pedal too far as i recall moving the entire range now that you mention it.

would this mean that i ruined the master?

should i try an hook up a vacuum to the line? if so how do you do that? I appreciate everyone's help.

The master cylinder could very possibly be shot. I have had it happen to me on two different trucks, both 63's. I replaced wheel cylinders and when going to bleed it out the master cylinder got shelled out. It's not unusual.

did you have someone helping you?
ron
by the way, it is not oil , but brake fliod that you use

ditto! If you put oil in the system you are going to need some professional help.

you need 2 people for this operation. 1 to pump the brake peddle. then you hold it down and the 2nd person cracks that l/rear bleeder and releases air and when they close the bleeder, that is when you can release the pressure on the peddle and start pumping again. hold and release again as previous until there is fluid coming clear of air and then move to the r/rear. you shouldn't release the pressure on the peddle until the bleeder is closed or you will suck air back into the system.
on these vehicles you start at the wheel which is furthest away from the m/cyl. and work to the one that is closest at the end.
ron
it sometimes seems to take forever to get that first one started- have patience

Thats what im wondering,it takes 2 usually to bleed the brakes

it takes 2 to do a lot of things.I sort of had a feeling that there was something missing there from his writings
well you have to learn somehow
ron

Thanks guys again for all the insight. I'm using brake fluid so my earlier comment about oil was a typo and did have some help so that I could bleed them while someone handled the pedal.

One thing that confuses me and maybe someone can confirm....when I unscrewed the rear brake line from the master (there is two wells one for the front brakes and one for the rear)and put my finger over the connection point for the rear line, and had the brakes pumped, I did being to get suction and back pressure on the brake pedal. I would think that because I got the pressure build up doing that, that the master is working and maybe air in the line somewhere? Would that make sense?

I'm dying here having had the truck out of commission going on two months....I removed the bed using a front end loader to get it off the frame and removed the old floor which was covered in diamond plate steel (the truck was formally a tow truck). I also wire wheeled and painted the frame from the cab to the rear bumper.

Again thanks for the support fellas. john

When you say you have a drum brake on each wheel, we are assuming all 4, correct? If you have disc on the front, you probably tripped the switch in your portioning valve.

you needed to pump and hold the pedal THEN open the bleeder valve until pedal drops then close bleeder then let off pedal then repeat procedure until you have only fluid(no air or bubbling)Make sure you dont let master run out of fluid or you'll have to start over.Do this at each wheel then go around and check each 1 more time to be sure all air is gone.DONT LET OFF THE PEDAL with a bleeder valve open or you'll suck air into the system thru the bleeder.need 2 people unless you have a vacuum bleeder

when you unhook a line,let the fluid in the master run out,or leave a bleeder valve open AFTER releasing the pedal, you are letting air into the system.dont do any of these things or you'll never get it bled

appreciate the direction. I'm going to try this all over again and see what happens.

I do have four drum brakes one for each wheel. thanks guys. john

You have a dual res. master cylinder on a 64 with 4 wheel drum brakes? That's not original, is it designed for 4 wheel drums? Got any pictures of what you got?
Scott

Scott...thanks for the continued interest. Yes, its a dual resevoir with each wheel having drum brakes. I dont have any pictures of the brakes, but have a few through the link below. All of these are photos before I started my restoration. please let me know if you have any additional thoughts.

http://s1133.photobucket.com/albums/m597/johnnywaz212/

Another notable thing about the truck is that it was a tow truck in its prior life. Note sure if they had to change the brake system to account for the additional weight the truck dealt with.

http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-92474.html

Above is the link to an in-expensive vacuum set up. I use an electric vacuum pump with mine to save time.

Wanted to get back and say thanks for all the assistance. I got the brakes working. There was air in the lines and with the help of the vaccum pump and some patience we got it going.

Expecting to get my bed cross sills this coming week from Mar-k, so hopefully I'll have her out on the road by next weekend.

john