Hey all,

so my vacuum **** the bed this morning so I’m looking at a kit that can be used to convert to a master cylinder and disc brakes on a 55 olds 88. Any suggestions?

 

If everything else is working fine, I'd have the power brake booster rebuilt. There are many other threads taking about the mods you need to make. (you lose your defroster because you have to modify the firewall and need to change the brake pedal completely) There are no simple direct bolt in kits.

 

Scarebird has a kit to mount disc brakes on your 55 but they don't have a replacement or a kit to change your master cylinder.

https://scarebird.com/index.php?rout...tegory&path=62

 

Have you pulled the rubber hose off of the vacuum tank( after a startup run and shutdown) and listen for a sucking sound? If none it could be the vacuum tank is shot or the valve in the hose next to the carb has gone bad. Well worth a check because there is quite a bit of fabrication required to go modern and isn't cheap to rebuild the old Treadle -Vac or replace with a new master and swing peddles with the mods that are need to the firewall... Just saying check your options before you dive into this it looks easier than it is.....Tedd

There are a few threads on these modifications

 

Have you checked where you are losing vacuum yet? Is it at the master or the booster tank or perhaps the valve below the carb or any of the hoses. Check them all out because to fix the tank hose or valve is cheap but to replace the master/ booster combo requires a different set of swing peddles and modification of the firewall. Looks easy but requires quit a bit of fabrication skills. but doable..... Tedd

 

Thank you all for your feedback. I am slowly going through each valve checking for seals and possible air leaks. It’s sounding like a possible challenge to do the switch. Does anyone know then ID tubing size for the cylinder to carb as I looked and it’s using a garden hose sigh. Thanks in advance.

 

Well, after closer inspection previous owner used totally wrong sized vacuum hose. (Huge) I’m going to try going to stock first which I believe is 3/8 tubing and see how that works. Visual inspection of all parts otherwise seem to check out.

 

Tedd is right i wad toying with the same idea with my 57 olds and I'm glad I stuck with my treadle vac. Works great now and got it rebuilt at karps power brake for 500 bucks. Another cheaper than the conversion and car stops great