Hey all, so I have a 68 Newport that was factory drum all the way around ( not sure if they ever came front disc)

I converted the front to an ssbc disc brake kit years ago. It’s always been good, never great.

I had to run a vacuum pump because I only make about 12 inches of vacuum and that kit needs 17+. My pump failed 2 summers ago and brakes haven’t been the same since. I have added a new vacuum pump that keeps me at 18-20. Tested my booster, it seems good, replaced the master with another factory style master. After me loosing my mind, I paid a shop to look at it and they are saying the factory master doesn’t move enough fluid for the disc brake kit…… worked for years…..it stops the car enough to drive safely, but I could be doing 50 and hammer on the brakes and there is 0 chance they will lock up. I don’t know if I bother spending $400+ on a willwood master or what to do. I called SSBC and they suggested going to a hydro setup. Seems unnecessarily. Please help!

 

Something that matters is bore size of the master cylinder, find out what your kit requires and what your master cylinder is.
To large of a bore will make for a hard pedal making the brakes ineffective, to small will give a soft pedal but the master will run out of travel causing ineffective brakes. Bore size and stroke make all the difference so you need to make it correct.

 

You may need to try one of these "https://www.manciniracing.com/mbmmomacy.html" to get the correct MC as this will have the built in residual valve and be correct for your application?
I have run as low as 3.5" of vacuum with power brakes on my old Cuda and could hold it in the beams and lock it up at will ! No vacuum pump required! Mopar 284/484 camshaft in a 340 cid.

 

My 2 cents that saved me a ton of aggravation. My 68 has factory front disk brakes (NO POWER). Stopping was scary. Brake fluid just sitting there attracts moisture like flies on a roadkill. I flushed the system which I later found out should be done every 2 years. Water in the brake fluid boils almost instantly causing a myriad of problems. My brakes now are so incredibly better. My modern-day Tacoma feels like it has less stopping power than my 68. For the price of fluid why not give it a whirl.

 

Thanks everyone. I checked factory vs the Mancini suggested and they are the same bore. Can’t seem to find stroke specs. I am waiting on a reply from SSBC on what I should have. Hopefully they can get me that info and I’ll report back.

 

thanks for the suggestion, it is all brand new fluid as of last summer so not even a year old.

 

Find a better brake shop..... Someone needs to have the tools to check the system and figure the issue out....




Then they can figure out were to start and isolate the issue....
Cheers

 

yeah i'd get a second opinion. and, when it comes to something important like stopping that land yacht, yeah, i may sink some into those brakes.