2 1/2" rear drum brake upgrade FWIW

[millsroger]

A 20% increase in rear brake power can be had for under $30.

There is a 1 3/16" dia. wheel cylinder used on some 1 ton 454's that fits perfectly on all models with smaller diameter wheel cylinders. Some are 1" and others are 1 1/16". Here are part numbers:

Brakeware 33708
Wagner F79768
Bendix 33708
Raybestos WC37337

Larger area x same brake psi equals more shoe pressure.

 

[THEFERMANATOR]

I checked and the 1 3/16" wheel cylinders are for DRW apps, and the 1 1/16" ones are for SRW applications.

 

[millsroger]

There are also 1" versions out there that also fit and are the cheapest, so some trucks may have them due to a cheap PO, or just due to an oops.

 

[THEFERMANATOR]

The 1" came stock on the 2.5" wide shoes. Never understood why GM put the small wheel cylinders in with the narrow shoes. But I believe the 1500's with tiny brakes also had 1 3/16" wheel cylinders with a more aggressive proportioning valve. I put a 93 1500 valve in a 2500, and talk about BRAKES!

 

[millsroger]

Corporate wisdom is like military intellegence--contradiction in terms. All I know is that if you load your rig to max and turn off the ABS all four wheels should lock at the same time. That puts you at the limit of the tires. You also need to remember that towing is a different animal, might be a lightly loaded truck with a heavy trailer--not good---jacknife looking you in the face.