Technical HELP! break problem on a 1949 Chevy

So I've bled the breaks a ton yet they still need to be pumped to work. They act like they have air in the system yet I'm pretty dang sure I've got the air all out. Could anything else cause this? Master cylinder? Thanks in advance.

 

Adjust the brakes (note sp), using a shop manual so you turn the adjusters the correct direction. Then adjust the free play on the master. You should then be stopping. If not, something is put together wrong.

 

Thank you 302gmc I'll check that out

 

We did just put new wheel cylinders In the front would they need to be bench bled? I wouldn't think so but what do I know.

 

No, they are designed to be bled while installed. The issue sounds like they are not adjusted properly. The brakes should be adjusted out until they just start to scuff when turning the wheel. After the wheel you're working on starts to scuff, hit the brakes and turn the wheel again. If it does not scuff adjust until it starts to scuff, hit the brakes again and repeat until the same amount of scuffing occurs after the brakes are applied as before. Move on to the next wheel and repeat.

 

Thanks guys

 

The way I was taught to adjust brakes in high school, crank the star wheel till the brake is locked on ,then count how many stokes till the wheel begins to move, repeat on each wheel . the idea being to get them all the same ,if you do not the car will pull to that side when braking.

 

also, be sure the bleeder is on top

 

Okay so I adjusted both the fronts witch are the only ones we've messed with since we started having this problem and still nothing. Any other ideas? I'm about to do the rear just because why not.

 

Brakes that pump up do not have air in the system. Go back to the adjustment first. Are the shoes new? If so, the pedal also may get better as the shoes conform to the drums.

 

This thread is interesting, we have breaks ( coffee breaks ? ) and a witch too.

 

What was the original problem???

I wouldn't touch the rears until I figured out why I couldn't get the front working.

Anyway, you are aware that the adjusters on each cylinder turn in opposite directions if they are the original Huck brakes???

 

Hi 49styline,

Could you describe the bleeding method you used, including the sequence of bleeding the 4 wheels?

When you had the brake lines disconnected did it drain the master cylinder?

Why did you replace the front cylinders?

Did were the brakes before the cylinder replacement?

 

Brakes that pump up most certainly may have air in the system. Why would you think otherwise?

 

Were they working prior to the work? A master cylinder rebuild did wonders for my 51, make sure you hone the cylinder though.

 

Okay so in the beginning the brakes were okay just weak. the pedal didn't need to be pumped up and was consistent. We then replaced both the front wheel cylinders because they weren't engaging and now we have this problem.

 

If all you have done is replaced the cylinders, you have the same as you had before. Cylinders that work and worn brake shoes. You need to adjust the screws in the end caps of the cylinders (in opposite directions)to push the shoes out to where they will make the shoes put pressure on the drum. Probably new shoes would be good too. There were no self adjusters in 1949.

Google Huck brakes, there is a world of information out there that tells you about them.

 

We started with the farthest wheel from the master cylinder and pumped the pedal up till it was hard, held It and opened the bleeder valve, let the fluid come out, and while the pedal was still to the floor we closed the valve and repeated the process.

 

49 chevy brakes are huck brakes, not the better bendix. The huck ones suck D, but lets see if we can get you going...

have the shoes been arched to the drum? When you pull the drum and look at the shoes what does the contact area look like?

You're on the right track with your bleeding. before you keep doing this though, adjust the drums until they barely start to drag.

you can do this by feel and listening. get the wheels off the ground, and turn the adjuster while spinning the wheel until you hear the shoes just start to make contact on the drum.

@Ford blue blood has it right.

You will still get a good pedal with well adjusted drums and proper bleeding, but if the brakes feel weak when it comes to slowing the car down, the shoes are most likely not making enough contact with the drum.

I would get new shoes, and fit them to the drums by using sand paper for a sanding block, (which I can see from your avatar you have).

Pull the drums and line the inside of the drum where the shoe makes contact with 80 grit adhesive sandpaper. turn the adjusters out until they are dragging a bit and turn the wheel. repeat this process a few times, and pull the drum periodically to see how much of the lining is being sanded down to fit the drum.

Once you have a satisfactory contact patch, reassemble and test the brakes again.

 

My brakes turn the same way to adjust on each side.. Maybe there not stock

 

Since there is a possibility your brakes could have been updated would you describe them or put up a picture just to make sure what we are dealing with??

 

Does it look something like this?? Brake parts for front & rear are the same except for cylinder bore and a couple small parts.

 

Update: rebuilt the master cylinder and it still does it!!

 

Have you got them working yet??

If not please verify that they are Huck and have the adjusting wheels on the ends of the cylinders like the picture shows.

 

If you turned all the adjusters the same direction, you now have half of them backed off all the way.
Go borrow a shoe/drum gauge from a mechanic & adjust all 4 wheels from scratch. And adjust the master free play to "I can just barely feel the play"...

 

302GMC
I don't understand the reluctance to tell somebody if his brakes look like the picture. He probably does have Huck brakes and has been bitten by a common source of confusion.

All he has to do is take off a drum, turn the toothed caps and he will see which way each has to go to make the screws go in or out.

The end caps on the cylinders will turn in either direction. They are both the same thread, right hand. Just because you can turn both the caps in the same direction doesn't mean you should.

 

Pinch off all 3 brake hoses. What pedal like now? If it high and hard your problem is in the wheels. If not you have a MC problem. If MC is ok, release one clamp at a time till the pedal goes low. That is the wheel with the problem or axle if it is the rear. Hope this works for you.

 

Good idea frosty I'll try that.

 

Don't pinch any hoses. You can damage the inside of them, specially if they are older.

This is a problem pecular to Huck brakes. The shoes wear, people try to adjust them. You have to turn the adjuster wheel on the ends of the cylinders in opposite directions to make the screws in them go in the proper direction. If you turn them both in the same direction all you do is chase the space you want to take up back and forth across the top part of the brakes.

In this case the shoes are probably worn enough to max out the screw on one end of the cylinder without taking up enough space to bind them against the drum because, by turning the other end in the same direction you have screwed that adjuster screw all the way into the end cap. Amount of space stays the same so you never gain adjuster distance to push the shoes against the drums.

Just look at how the adjuster wheels work. You will see which way each should turn.