38 Lasalle front brakes grab

[lasalle38]

38 Lasalle owner with a brake problem. Followed the adjustment process as it's written. All new shoes, cylinders , hoses and drums turned. When applying the brake petal, both front wheels lock up equally to the point that it is not drivable. Been through all the obvious things and this is not my first brake job. I have been doing this for 60 years. What is going on? No fluids or oil on the lining.

[J. Russo]

I'm not familiar with 1938 models. I burned up a brand new set of front shoes on my 1941 after a master cylinder rebuild and all new shoes and wheel cylinders.

I didn't adjust the brake pedal correctly at the master cylinder which turned out to be the cause.

[Warren Rauch #4286]

Just a couple questions.
 Has the master cylinder been replaced with dual master?
 How do you release the brake when it locks up?
 What kind of brake shoes?  Molded should be OK. Riveted may need to be cam ground.
 

   Possible causes;
     1) a pinched brake line -it would need to be nearly shut off to slow the return fluid
     2) weak brake return springs on wheels( Specs see 1938 shop Supp.)
     3) Master cyl rod adjusted wrong - You need some (book says 1/4 to 3/8 inch) free play in brake pedal . This is needed because the return hole can get blocked by piston/cup .Should drag all 4 wheels ,if they are all adjusted the same.Could drag only best adjusted if not.

Warren

[Michael Petti]

All the things Warren mentioned are possible and need to be checked. Today's parts tend to be of dubious quality. I did a brake job 60 cdv (ALL DRUM) and had a similar problem on the rear brakes. The first new master cylinder leaked out of the box. The grabbing was caused by a brand-new wheel cylinder that was so poorly manufactured that the pistons would not retract, causing the shoes to drag, heat the brake fluid to boiling and make the shoes drag. I fixed the wheel cylinder with a lot of honing, and all was good. If they ran ok before the job then it's possibly in the new parts. One other thing. My old shoes were so worn they made no contact in rear. With new shoes I discovered the contact points on the backing plate had worn and a ridge formed catching the shoes as they tried to return. I drilled a small hole in the affected areas, filled it with JB Weld, sanded smooth and the shoes returned properly. Good luck on this. Please let us know what the solution is when you find it.