I thought that the 1961 DeSoto has Chrysler "Full
Contact Brake System".
If so, the front brakes, as with all internal
expanding type brakes, are self energizing; but not servo acting. This
means that when the brakes are applied, the brake shoe presses harder on the
drum than the hydraulic pressure would indicate, because the shoe is trying to
"chase" the drum around, but cannot move, since it is held by the backing
plate. But the shoe does NOT press against the other shoe, therefore, not
servo action.
In the rear, only the forward shoe is self
energizing in the forward direction, the rear shoe is self-energizing in
reverse.
This is different in the "Bendix" style brakes,
where the bottom anchor is floating. In this case, the shoes are
self-energizing, and servo, in both directions.
In your problem, it is one of the few disadvantages
to the "Full Contact" system, and one reason why Chrysler cars used a driveshaft
parking brake. If you have a driveshaft parking brake, check the
adjustment. Since it is independent of the service brake, it would have
nothing to do with how hard you press down on the service brake pedal, but if it
is out of adjustment, you can press the parking brake all the way that it will
go, and the brake will grab no harder due to it being strictly
mechanical.
Check it out.
Mike Higgins
1955 Belvedere Sport Coupe
----- Original Message -----
Sent: Tuesday, July 23, 2002 17:49
Subject: [FWDLK] PARKING BRAKE
Hello all. A question about my 1961 DeSoto.
When the parking brake is set you can put the car in drive and it will not
move forward. But if you are on a hill or put the car in reverse its like the
brake is barely on ? The parking brake pedal only goes down about halfway
and I can push with all my might but still won't hold in reverse like it holds
moving forward. Thanks for your thoughts.
Rich
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