manual to power brake swap

has anyone made the swap from manual brakes to power on a automatic car i would like to to do it any help and what route did you go thank's for the in put

is there a problem with the manual's u have now ??? the one issue u'll have is the brake peddle. u can get a p/s peddle or drill the pivot hole 2" lower when u go with a p/b unit. i did a little looking for my '73 but i elected to do a complete manual drum upgrade.. new everything except the hard bk lines. my peddle was hard and i really had to push to stop. but i figured it would have not come from factory like that, so there must be something else wrong.. as i started replacing the wheel cyl's i saw they were not moving when i tried to push them in. even with bk lines disconnected. the wheels are done and hopefully today i'll get the m/c replaced.. then bleed..

There should be several threads on the forum on this subject do a search.

Short version is you need a donor car or go with aftermarket. The brake pedal changes, master cylinder is smaller dia., vacuum booster and connection, proportioning valve and lines, spindles have to change to mount caliper, rotors and calipers also needed. Go with new rotors you can rebuild the calipers it is also easy job unless cylinders are rusted. You should also replace the rubber hoses and not a bad idea to replace all the hard lines if they are original. It is not difficult just have to have all the right parts to do it correctly. Automatic version will be easier to find that straight drive for sure.

When drum brakes do not work properly it is usually due to incomplete brake job. When drums are turned that increases the diameter of the drum. The shoes come to the original diameter so they only hit in small area in the center of the shoe arch giving poor performance. The shoes need to be ground to the new diameter of the turned drum. This can cut away half the new lining. Drum brakes of this period will perform about the same as disc when correct but will not hold up under repeated panic stops and when wet. You should be able to slide all four wheels with drum brakes. Not the fastest way to stop but should be able to. The wheel cylinders are very cheap so not worth a rebuild.

I have a 73 vert with factory P.D.B. H code automatic and a 72 vert with factory P.D.B. H code with 3 speed manual. The 73 has 48,000 miles and the 72 was a one owner with I believe 80,000. The rear drums on the 73 are I think 1/2" wider than the 72 is and have big cooling fins. Nothing on the Marti suggests any different brakes ordered. Parts house I believe lists 4 different shoes for these cars for rear.

Do your search of the forum and there might be something on the West Coast Cougar Classic site on the subject maybe a video.

There has been several posts on this swap lately. I have posted quite a bit about my own experience switching from manual drums to power disc/ drums including pictures of the firewall and, in my case, 4 speed brake pedal. The Automatic would be the same change. Rather than me repost and repeat what I did, PM me and I can help that way. Again, this is from my own experience, so not necessarily the only way.

Also there have been post regarding the proportioning valve that could be required to be switched. Again there are alternatives like using a separate adjustable rear brake valve with the original distribution block you now have, or switching to a new combo valve mentioned in the posts.

Geoff.

EDIT:

OK, David was typing at the same time I was. He has very good info there in his post. However you may NOT need to replace your front spindles depending on which brand of brakes you go with. Several kits are available that utilize the original spindles. I went with SSBC's 4 piston Kelsey Hayes style that work very well with standard 14" wheels. You have some research to do, but a worthwhile upgrade in my humble opinion.

You might want to consider hydroboost instead of vacuum for your power brakes, smaller and no worries about having enough vacuum if you go to a hotter cam. This has also been discussed in the forum.

at this time i do not want to change out the brakes

. when i go for long drives my foot starts to hurt from the hard peddle non power peddle makes for a long drive the car stops ok just a very hard peddle so power assist seems like a good thing to do a. Donner car is out just wounder what brand was used i looked for threads and had no luck i will look some more thanks

I'm looking to do a similar upgrade, but just going from 4 wheel drum to a Disc/Drum combo and keeping it manual.

I have also looked into the Power upgrade with aftermarket kits but they are $$$$$

Wilwood has a kit that uses the Drum Spindles, but needs a 1" boar master cylinder and new Disc/drum proportioning valve.

SSBC has complete kits will all parts needed, using your existing Drum Spindles.

Summit also had a kit which is put together by SSBC.

there are many many options without needed a donor car these days, but they all depend on how much you want to spend.