Brake grabbing

[Cannuck]

Hi I am looking for any help with a brake problem that has come up .Last weekend I was going to town and was surprised when applying the brakes the drivers side front brake was grabbing , after a couple of hard brake applications it seemed to sort itself out .

Next day I tried it again same problem .

The car has now sat for a few days tried again same problem and same solution applied the brake a few times and once again problem solved .

Not sure what the problem is brakes master cylinder and wheel cylinders are all 3  years old.

Put the car on jack stands and did the minor adjustment it didn't help.Checked for any signs of brake fluid leaks found none .

Thinking I may be looking at a new wheel cylinder.

[Cannuck]

Forgot to mention it was down a a little bit of brake fluid maybe an ounce.

 

[keithb7]

Pull drum and have a peek. A little brake fluid on the shoes can do this. Or How about a partial collapsed flex hose holding return pressure?

[kencombs]

2nd the suspicion of a leaky wheel cylinder.

[desoto1939]

Do you have bobded brakes shoes and how old are they? We have been finding that the braking material on the bonded shoes sometimes gets hard and glazed and this will cause a wheel to pull. I have a similar issue with my 39 Desoto the right front and after the brakes warm up the issue goes away. It also might be just a moisture issue.  Pull the drum sand down the lining clean out any dust with brake shoe cleaner. This helps on my 39 Desoto.

Rich Hartung 

[Abe Lugo]

We had a sticky cylinder, it was easily identified by visually looking at the rear of the wheel to see if there was fluid coming down.

what happened on our is that there was rust building up in the lines or the master.

took apart the cylinder cleaned it out as mach as possible, then honed it with the brake cylinder hone. Then flushed out some fluid and proceed to re-assemble and bleed the system, also need a bit of adjustment.

Mainly check to see if its leaking fluid and then you would find your issue.

 

If the steer pulls hard when you brake its in the front.

 

[51cambridge]

1 hour ago, desoto1939 said:

Do you have bobded brakes shoes and how old are they? We have been finding that the braking material on the bonded shoes sometimes gets hard and glazed and this will cause a wheel to pull. I have a similar issue with my 39 Desoto the right front and after the brakes warm up the issue goes away. It also might be just a moisture issue.  Pull the drum sand down the lining clean out any dust with brake shoe cleaner. This helps on my 39 Desoto.

Rich Hartung 

I 2nd this. My bonded ones do the same. A little sand then brake clean and it’s good to go.

[Dodgeb4ya]

2 hours ago, desoto1939 said:

Do you have bobded brakes shoes and how old are they? We have been finding that the braking material on the bonded shoes sometimes gets hard and glazed and this will cause a wheel to pull. I have a similar issue with my 39 Desoto the right front and after the brakes warm up the issue goes away. It also might be just a moisture issue.  Pull the drum sand down the lining clean out any dust with brake shoe cleaner. This helps on my 39 Desoto.

Rich Hartung 

I bought enough NOS asbestos linings and shoes for all my old cars and trucks for any relines off ebay.

IMO modern linings are too hard and can grab out of the blue. Modern dark colored hard linings for our old cars drum brakes IMO are now dangerous.

Copper was removed in the last couple years too.

Any fluids on the linings of course needs to be ruled out.

[brian b]

My 39 used to do this, the pistons would stick in the wheel cylinder when the brake was applied,  then wham!, the brake would come on full force. This was the left front, and it would try to throw the car out of the lane.  The pistons were  corroded,  almost a galvanic  corrosion  from dissimilar metals in contact.  This in spite of being NOS  packed in cosmoline when I  first got them .  Added to several other  brake related  problems,  I  converted to front discs  and no more brake problems.

 

                                                                                                                                                                     brian  b

[Cannuck]

Thanks to everyone I will remove drum and try to find the problem.

Well no obvious leaks ,the shoes are cupping don't know why .Will sand both the drum and shoes and reassemble .

[Cannuck]

Tried to post a photo no success told only allowed 3 MB

 

[wldavis3]

If you are using a PC (Windows operating system), you can reduce the size of your photos in Paint.

[kencombs]

23 hours ago, Cannuck said:

Thanks to everyone I will remove drum and try to find the problem.

Well no obvious leaks ,the shoes are cupping don't know why .Will sand both the drum and shoes and reassemble .

'Cupping'?  A pic to explain that would be great.  Are your linings bonded or riveted?  If they are cupping across their width, replacement is probably warranted.

[Cannuck]

This is the cupping I was referring to .Already sanded shoes and drum noticed uneven wear pattern so will try adjusting again

[kencombs]

Pic is really closeup!  But, it appears to be bonded lining.  If so, look carefully at the area under that cupping.  It may be de-laminating from the shoe.  If that's the case, you may suffer a full lock up if it comes loose.

[Sam Buchanan]

This "cupping" looks very similar to how the new shoes purchased from Bernbaum looked on my P15 after a few miles. You can see the areas of the shoe that are not contacting the drum in the photo below. I assume they are due to manufacturing variations and will disappear as the shoe wears into full contact with the drum. Arcing the shoes would be the ultimate solution but I don't know of anyone locally who offers that service.

 

 

 

Edited September 29, 2019 by Sam Buchanan

[Don Coatney]

Mark your brake shoes with a "sharpie". Drive a few miles and inspect for even wear.

 

[Cannuck]

Thanks Don will do

[Cannuck]

This is the cupping I was referring to .Already sanded shoes and drum noticed uneven wear pattern so will try adjusting again

Sam my shoes also came from Bernbaums I am impressed with your home made adjuster.I am going to print your picture and attempt to make one

[Cannuck]

Just a little update So I made Sams tool and checked the shoes and according to the tool my shoes are fine .Marked the shoes with a sharpie as Don suggested and went for a spin applying the brakes on numerous occasions and the sharpie marks are all gone .Also no pulling at any time .

It will have to remain a mystery.

[kencombs]

Another likely cause is high humidity, especially in condensing situations.  Cool metal, sudden rise in humidity can cause condensation that creates a little flash rust on bare metal, i.e. polished drums.  Some lining material is very sensitive to that.  I have a '97 F150, bought new whose brakes do that. especially when unused for a few days.  the first brake application is touchy!

[Cannuck]

Well I thought I would give an update on the brake issue . It is its still doing the same thing grabbing until I apply the brakes a few times and then  its fine .

I disassembled everything and checked again for leaks and sure enough found brake fluid on the pipe between the two wheel cylinders tightened the threads cleaned everything with brake cleaner and put it all back together .

I will test drive the vehicle and make sure that it is no longer leaking but I imagine I will be looking at new front shoes.

Thanks again to everyone who helped me .