Kip Page
Well-Known Member
I have power front drums brakes and I want to convert to disc.... do I need the booster etc too?? what kits are the best...thx
Even with an adjustable proportioning valve?Your drum brake booster won't provide enough boost for front discs. You will need to replace it with a dual ballast unit.
Yes. You will end up with a hard pedal and not enough boost to lock the wheels. Front or back. If you don't upgrade to the dual ballast booster, you would be way better off with no booster at all. Ask me how I know.Even with an adjustable proportioning valve?
So I guess I pissed my money away on an adjustable proportioning valve then, haven't installed it yetYes. You will end up with a hard pedal and not enough boost to lock the wheels. Front or back. If you don't upgrade to the dual ballast booster, you would be way better off with no booster at all. Ask me how I know.
Not necessarily. You will need a proportioning valve with front disc and rear drums no matter what. For the most part, they're job to delay the pressure to the rear brakes so they don't lock up first sending you into an end for end spin when you want to stop. The adjustable one just gives you more input.So I guess I pissed my money away on an adjustable proportioning valve then, haven't installed it yet
I'll bite...how do you know?Yes. You will end up with a hard pedal and not enough boost to lock the wheels. Front or back. If you don't upgrade to the dual ballast booster, you would be way better off with no booster at all. Ask me how I know.
Some lessons are costly......My 68 Charger had power drum brakes originally that worked fine. When I converted to front discs, I couldn't stop the car and the pedal was hard. I thought my booster was bad so I sent it to Booster Dewey for rebuild. Reinstalled it and had the same issues. Then I replaced the master cylinder thinking that was the problem. It wasn't. I finally called Cass at Dr Diff and was told the same message I gave in post 7. I needed the dual ballast booster to provide enough boost for the front discs. If I had asked the question like Kip Page did before spending a few hundred dollars and a couple weeks of trial and error wondering what the hell was wrong, I would have saved myself a bunch of grief and money.I'll bite...how do you know?
I'm not here to argue the point one way or another. Just trying to save some people some grief. All I have to go on is my own experiences and word of mouth from others that have been down the same road. I had a 70 Challenger with disc brakes too but it was manual not power so I have no input as to whether a single diaphragm booster is enough. If it works good for you, that's all that counts. This is a B body site and from what I've seen and been exposed to on the 68-70 B body cars with power disc brakes, (which this particular thread pertains to) The factory provided the dual diaphragm booster. They would not have done that if they felt it was not needed.Well great, I guess I have to replace the original single diaphragm brake booster on my Challenger... Oh, wait, the brakes have worked great ever since 1970...
Maybe the fact that 80+ % of the disc brake cars having single diaphragm boosters should be considered here....
The fact allot of guys run discs with no booster at all means something...
Perhaps pedal pressure, mechanical advantage, M/C bore sizing and the booster all are a balanced package... And if you get it wrong then either you get a hard pedal or a very touchy pedal..