1969 Dodge Dart Custom Sedan Slant Six, Father-Son Project

The lackluster 9” drums on all four corners gave us the original notion to upgrade to power brakes. All new cars have it, so it must be ‘better’, right? But the more advice I read, it seemed that a 2800 pound A-body with an excellent brake system needs no power boosting.

And given how a power booster will no longer fit under the hood – thanks to the looong aftermarket intake manifold – this was good news for us.

Wilwood offers a kit that upgrades 9” front drums to 11”, 4-piston-caliper disc brakes that (hooray!) utilize the stock control arms and spindle (only very minor grinding needed for clearance on spindle casting).

Also they offer a master cylinder upgrade that utilizes a smaller-than-stock 7/8” piston bore diameter, which adds lots of line pressure at the tradeoff of a little more brake pedal travel. Sounds good – a perfect recipe for a strong, effective braking system with great pedal-feel! Everything installed incredibly straightforward. Good instructions were included.

And although 9” drums in the rear may not need any reduction in line pressure to balance with the front discs, we went ahead and got an adjustable brake proportioning valve to install in line with the rear hydraulic circuit. Cutting that line got a little messy - always wear eye protection!


Easy to bleed the air out of the lines, right?

Nope. Ha! Just because you bench-bled the master cylinder doesn’t actually mean you properly bench-bled it. Are you sure you bottomed out the piston? Guess again. Then learn how to properly bleed each wheel. It took us 2 hours, but we were rewarded with a fabulous-feeling brake pedal. Our first attempt at all this had a pedal that would mush straight to the floor, regardless of ZERO bubbles coming out of the bleeder screws.

Man, they are NOT kidding when they say you have to be meticulous when you bench-bleed the master cylinder.

If you count up the number of fittings in the whole braking system – 34 fittings!! (including the bleeder screws) – there’s a LOT of room for leaks to manifest. Especially at the new proportioning valve, where we got to make out first-ever double-flared fittings after hacking into the stock rear line. We touched 20 of those 34 fittings during the installation/modification/bleeding process, and sure enough one of them had a tiny leak. Tightened it up, and all was good.

Oh, one other thing. The 1969 stock master cylinder had the aft reservoir feed the front brakes. Its reservoirs were equal-volume. The Wilwood master cylinder has the larger volume in the forward reservoir, so we did make the brake line adjustments to give the front brakes access to the larger reservoir.