Brothers Trucks 1947-1959 Power Brake Installation


Brothers Trucks 1947-1959 Power Brake Installation


The Power Brake Kit from Brothers comes complete minus extra brake line, fluid, and various fittings – all of which can be obtained from your local parts store. The bracketry’s design allows for a clean and easy installation, while the compact size affords a nice fit in the frame rail.

Though a tad rusty, the old single-chamber master cylinder was still operating just fine, I liked the idea of not only upgrading to power-assist but having a dual-chamber system for obvious safety’s sake. (Note: the E-brake pulley immediately left of the cylinder needs to be relocated rearward with the installation. We’ll be installing an aftermarket unit later, so this was deleted altogether.)

Unless you’ve got a buddy in need of a stock master, the only thing you need to save is the brake pedal arm, as it bolts right onto the new cylinder linkage.

For location-finding purposes, the center of the booster/cylinder bracket bolts to the factory frame rail mount.

New holes need to be drilled for the rear mounting of the bracket, after which you’ll want to carefully bend the old brake line out of the way for future work.

Next up, install the plunger rod ear on the stock brake pedal, then slide them into the bracket with the supplied pivot bushing(complete with zerk fitting).

The power booster canister can now be slid into position and secured back on the bracket with the supplied hardware. The RB’s 700-R4 trans cross member came close to interfering with the booster positioning, but no modifications were needed; check for clearance before you get into trouble.

The plunger rod assembly goes in next, just as it was when the kit was disassembled.

The bracket also features a gusset-type support that attaches to the lower edge of the frame rail by simply drilling a hole and installing the hardware

With the bracket and booster all in place, We proceeded by bench-bleeding the new master cylinder. We bent up a short length for a steel line for the job.

All bled, filled with fluid, and the cap tightly installed, the master cylinder is finally reunited with the booster. While the kits with proportioning valves (disc applications) come with fittings, you have to supply them for the drum/drum style as we did.

Thanks to the folks at Brothers, brake line flaring was made easy with a new Hydra Flare. Then hand-held hydraulic tool makes the dreaded job of double flaring actually fun!

With the complete unit snugly in place, We bent up the new brake line configuration. Careful attention is always paid to making sure every fitting and union is as tight as possible – fluid leaks are not acceptable!

Brothers includes a see-through plastic fill bottle with the kit, necessary due to the location of the new master cylinder being further back from the stock access hole in the floor. The transparent plastic makes it easy to tell when the brake fluid is getting low, but you still have to use the old “finger-gauge” method for the master cylinder itself.

The last thing you need to do before wrapping up with full bleeding (the truck, not you) is to bend up and install a vacuum line for the booster. We choose to run a brass 90 off the manifold instead of just T’ing off the back of the carburetor.

We fashioned a piece of 5/16 hardline that threads into the 90 and then runs down to the canister.

The end of the hardline was barbed, then a piece of flex line cut and attached to it, and the plastic fitting on the booster. With good bleeding of all four-wheel cylinders, then a complete check for any leaks, we were back on the road – in a much safer way, to boot! Nothing beats a good brake system, no matter what type of vehicle you’re driving.


Staff Writer
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