Installing (adding) Power Brakes, '69 Mustang.

[f.f.jones]

Our summer driver is a six cylinder 1969 Mustang convertible base model, no power options. It's due for brake job soon and we're wondering if it would be practical (not too expensive and not too difficult) to add a vacuum booster to make braking easier and more effective. We don't want to get into a disk brake swap or anything complicated. We are hoping that sourcing the correct booster and maybe a new or different master cylinder, possible linkage changes, and making the proper vacuum connection will enable us to complete the installation relatively quickly and without a lot of difficulty.

Is this a reasonable upgrade? Are there hidden problems here we don't see?  Please comment if you have any information or hints. Thanks.

 

 

[rocketraider]

Power brakes were a fairly common dealer installed option in those years (or were for GM cars, bound to think Ford and Chrysler too) so this shouldn't be a difficult job. 

 

Figure out the OE booster, master cylinder and brake pedal pushrod part numbers and see how much different they are from the non-power parts. Those and a vacuum source are all I can think of that are needed to convert. 

 

There might be some difference in brake pedal installed height between power and non-power brakes. But you have the advantage of Mustang's popularity and parts support.

 

[Rusty_OToole]

You need the appropriate master cylinder and booster and a vacuum line to the intake manifold. There should be a pipe plug in the manifold you can remove and put in the pipe fitting. Do a web search for 1969 Mustang power brake master cylinder and booster. Last time I did this it cost around $200 for parts.

Be sure you get the right MC for drum brakes, discs often use a different master.

Edited July 20, 2023 by Rusty_OToole (see edit history)

[ted sweet]

doesnt make the brakes more effective

Edited July 20, 2023 by ted sweet (see edit history)

[Bloo]

Well if it was my car, I would prefer the manual brakes. Old fashioned power brakes are easier to push, but they are sort of a learned skill. If you want them you want them. It should be a bolt-in in that car, pretty much the way @Rusty_OToole said. The pedal ratio is probably different. There could be a different hole for the rod or it might need a different pedal.

 

I'd check with West Coast Classic Cougar. They have some Mustang stuff, but those parts you need are likely the same as Cougar anyway. I've bought brake rebuilding parts from them for a 70 Marauder a couple years ago, the most critical of which was the rebuild kit for the differential pressure switch, which of course started leaking when I tried to shut it off. They seem to be able to source quality parts, and if the only parts available are crap they will tell you. At least that was my experience.

 

Edited July 20, 2023 by Bloo (see edit history)

[Matt Harwood]

When we bought my wife's '66 Mustang GT 10 years ago, it had power brakes that someone had added. The power assist was ridiculously over-boosted--you could almost stop the car by blowing on the brake pedal. It was so light that the brake lights didn't work because you never had to push the pedal far enough to activate the switch.

 

Anyway, we removed the power brake system and used a manual dual master cylinder from, I think, a 1974 Maverick. It works perfectly. Nice pedal modulation but not tremendous effort. Melanie is thrilled with it and it feels quite natural. 

If you're happy with how the brakes feel and work now, then I'd just service them and get them into top condition without adding the power assist. The Mustang is a lightweight car, it doesn't need a lot of help stopping if everything else is healthy. I'd never want to go back to the way the brakes used to be, that was awful.

 

Hope this helps!