1939 La Salle Brake Grabbing

[NH LaSalle]

Two weeks ago, I drove my 1939 La Salle to and from a show without any braking problems.  It was then parked in the garage for a week.  Backing it out to go to another show was no problem.  However, when going forward and applying the brakes, even lightly, the left front brake is grabbing with the chirping sound of rubber on pavement.

The car underwent a full, body off restoration and its original drum brakes were refurbished and it has 3000 miles on it since.  There have been no previous brake issues since the restoration was completed.

Couple of questions, both related.  What would cause this abrupt change?  And what's the fix...something simple such as a star wheel adjustment or something more substantial that would require disassembly?

[Jay Friedman]

My '49 does the same thing when I first start driving if it is not driven for one week or more.  I think it is the left rear wheel. To rememdy the situation before starting out I drive slowly around our subdivision and step lightly on the brakes as I go.  Finally it will stop grabbing.  If I take the car out for a drive after a shorter interval, the brakes do not grab when first starting. 

I was told it has something to do with the humidity here in Georgia.  I suppose I should pull all the wheels, lightly grease the "pads" on the backing plate that the brake shoes slide against and maybe re-adjust the brakes.

Any comments would be appreciated.

[NH LaSalle]

Jay

Thanks for the response.  It has been rainy and somewhat humid here.  I have a lengthy driveway.  Safer to try your recommendation there than on the open road.

[LaSalle5019]

You may also want to look from behind the drum for any signs of wetness from a leaking wheel cylinder. Maybe pull the rubber plug for the star wheel adjustment and look in there. The quality of replacement parts isn't too good these days so I'm never surprised to see wheel cylinders fail in a few years or few thousand miles. Brake fluid on a shoe will cause grabbing.

Hopefully it's just a humidity issue as mentioned above.

[Jim Stamper]

     I am not sure I know the symptoms enough to say for sure this is the problem, but a brake that grabs and bit and then seems to release can be caused by the internal collapse of a brake hose. It takes more pressure to get the juice past the collapsed spot, and the juice leaves slower when the pedal is released. The car will duck to one side a bit and then back again as the faulty line tries to keep up with the other brakes. They all don't work in exact unison as we wish they would.
     It took several shops to find the problem, and a simple replaced hose for the fix. I had read of the problem in the past but failed to spot it when it happened on my ow car.Jim Stamper CLC#13470  NH

[Michael Petti]

My 60 was having similar problems and it was from a  rake hose that had collapsed internally. The hose had been replaced about 5 thousand miles ago. Suspect everything, trust nothing. Another tribute to OUR favorite overseas parts supplier.

[Vertexrex]

The same exact thing happened with my 1938 LaSalle a week ago....and it was the left front that was grabbing and locking. I took the drum off and looked at the bearings and they were fine and well lubricated. The shoes and drums looked perfect and all the parts, especially the shoe return springs looked excellent....no leaks anywhere. I then went to a local mechanic who is old like me and immediately he said it was the brake hose. He said they may look fine from the outside, but the inside collapses somewhere and causes this. I found new front brake hoses at a reasonable price ($24) at Kanter and I installed the front left one today....now bleeding it. All seems good now, but I haven't driven it yet.

[LaSalle5019]

The hose delamination issue typically presents itself as a slow to release issue so, after braking, the car pulls to one side for a bit until the fluid trapped by the hose releases. The harder the brake apply the worse it is, particularly at higher speeds. During a steady apply it usually causes no issue as the high pressure from the master cylinder will easily pass through the restriction. It is on release, where the few psi from the brake shoe return springs trying to retract, cannot easily overcome the  orifice caused by the blockage and this causes a very slow release and pulling of that one wheel.

The OP's complaint is the one wheel is grabbing hard with even a slight brake apply.

[Jay Friedman]

As I wrote in the posting above this happens to my '49 when it hasn't been driven in a week or more.  When first starting to drive, one wheel grabs when the pedal is pressed even slightly. If I press very lightly driving around my subdivision the brakes gradually return to normal operation.  It does not do this if I drive it within a day or so of having previously driven it.  Most importantly, it has brand new hoses.

[Jay Friedman]

.... When first starting to drive, one wheel grabs when the pedal is pressed even slightly. If I press very lightly driving around my subdivision the brakes gradually return to normal operation.  It does not do this if I drive it within a day or so of having previously driven it.  Most importantly, it has brand new hoses.

Finally, Caddy Wizard Art Gardner was able to repair the problem of my '49's brakes grabbing when first starting.  I was able to determine that it was the front left wheel that was locking up when the brake pedal was even lightly applied.  Drove around my subdivision slowly and immediately after a tire screeching episode a walk-around inspection showed tire marks on the pavement behind the left front tire. 

Drove the car to Art's shop, where he put the car up on the lift and removed the left front brake drum.  Visually, everything looked normal.  However, slightly pulling down on the brake pedal from underneath showed the primary (front) brake shoe moving, while the secondary (rear) shoe remained stationary.  Art then removed both retracting springs and switched the front spring to the rear and vice versa.  Pulling down the pedal now showed the rear shoe moving, while the front shoe remained stationary.  One spring was much stronger than the other, preventing its brake shoe from moving. (Removing the right front drum showed both shoes moved.)

The bad springs were relatively new and had come from a commercially available kit of brake fasteners.  Luckily, Art had a pair of original springs in the shop.  Installing these as well as lightly sanding and cleaning the brake drum and shoes cured the problem.  My '49's brakes now work normally.