FWIW.
I had a very similar problem on my 57 1/2 ton with all stock wheels/brakes.
In retrospect, I think the problem most likely had to do with the rebuild I
did on the brake system.
Truck never had very good brakes, but I was careful and drove within the
limits. First failure occurred when right rear wheel cylinder began to
leak. Replace with part from Auto zone and cleaned up the rest of the
pieces on that wheel. Brakes still sucked.
Several years later I decided to redo all brakes because I was driving the
truck more. I bought new cylinder for left rear and new drums/brakes plus a
few springs etc at NAPA. Next I bought stuff for the front and fixed them.
Noticed some pulling (don't recall which way) and decided best thing would
be to put new cylinder on right rear. Purchased from Auto Zone or Bumper to
Bumper. Still pulled.
Hindsight tells me that my mistake involved mixing parts from several parts
houses. I think the wheel cylinders should probably all be purchased from
same vendor. I believe there may be differneces in the cylinders that
causes uneven braking.
In my case, I am fairly certain the rear brakes were causing the pull.
Might consider buying another wheel cylinder from the same vendor so that
they are matched.
My truck is in middle of frame-off so I haven't dealt with brakes in a
while. Let me know how you fix it because I'll have to deal with the same
problem eventually.
-----Original Message-----
From: Carl & Becky Ham <the_hams@hotmail.com>
To: oletrucks@autox.team.net <oletrucks@autox.team.net>
Date: Monday, September 16, 2002 9:33 PM
Subject: [oletrucks] Still having TF power brake problems - any further
advice?
>I wrote approx. 2 weeks ago asking for advice with my brake problems since
>converting to power brakes. Here's an update of what I've done but I'm
>still not satisfied and need some help.
>
>BACKGROUND:
>'56 Chevy 1/2 ton stepside with stock suspension and brakes. Purchased a
>power brake conversion consisting of a vacuum booster, master cylinder and
>mounting bracket (under floor). Specified 4 wheel drum/drum brake system
>when I ordered the conversion. Had a local garage install the system over
>the winter months. They had to make some new lines for the front brakes
>because they had so much trouble bleeding them with the new system. Also
>purchased speed bleeders for all four wheel cylinders. Got truck back in
>the spring, but didn't drive much as I was rewiring, installing power
>steering and tilt steering column, new automatic transmission, lowered
front
>end by removing two leafs from front springs and smoothed the dash.
>
>Finally got everything together and started seriously driving about 4-5
>weeks ago. Immediately noticed the truck pulling to the right during hard
>braking. Rear brake on driver's side smelled hot and eventually burnt the
>new paint off the drum after approx. 300 miles. Removed both rear brake
>drums and driver's side linings/shoes were 50% of the other side (both were
>new last year). Thought driver's side rear may have been adjusted too
>close, so readjusted both rear brakes and repainted driver's side drum.
>After a test drive the same problem on the driver's side (drum hot to the
>touch) compared to other wheels both front and rear. Suspected driver's
>side rear wheel cyliner bad, removed (it WAS full of rust, one piston
>stuck). Tip-off was jacking the rear end up, wheels turned fine until I
>started the truck and applied brakes, driver's side would not move after
>brakes engaged.
>
>Replaced wheel cylinder (local AutoZone had one in stock for $10.85),
rebled
>brakes and readjusted all four wheels per specifications (adjust in until
>drag, then back off 7 notches). Another test drive, SAME results. Took
>truck back to local shop that did the conversion and complained, they
>checked it over AND found when they installed the power conversion they had
>to move one of the parking brake cable pulleys back about 2-3 inches on the
>frame. Somehow this resulted in the parking brake on the driver's side
rear
>keeping the brake shoes engaged with the drum (when the brakes were
applied,
>but would later loosen up). Loosened the rear parking brake cables and
>driver's side drum doesn't get hot anymore. WHEW!!
>
>Test drove truck and it STILL pulls to the right during hard braking.
>Almost feels like the rear brakes are trying to move the truck to the
right.
> Do I need a proportioning valve to keep the rear brakes from engaging too
>early? I'm about ready to chuck it all and put in an IFS and Ford 9 inch
>rear end with disk brakes all around. Am I overlooking something? Any
>advice appreciated, sorry for the lengthy story but thought if I put the
>details in it would save a bunch of questions later.
>
>Carl Ham
>'56 Chevy TF Stepside
>Pontiac, IL
>
>
>
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