I have a 68 firebird with manual drum brakes. I want to improve them to some degree. If I add a power booster to make it power drum brakes, does that buy me enough or do I have to convert to disc. If disc, do you do just the fronts or all 4? I want to not spend a fortune at this stage if possible.
power booster will make the pedal easier to press.
disc brakes may decrease the stopping distance somewhat and reduce the risk of brake fade under hard/frequent braking.
in my opinion, 4wheel disc is not necessary for a street vehicle. you should be able to put on some '69 style floating brakes on the front fairly cheap. power brakes either way can be nice.
Now the next issue, where can I get a booster and what else is need to install it? I guess I want to try out Power drum brakes before going for the big money. Anyone make their drums power before, if so what are the steps? I may not have enough room for a full booster on the firewall, may need a slightly smaller one.
you can get a stock booster locally. a small booster can be ordered from Master Power, or other places. your engine needs good vacuum to run the booster... 18" is a good #. otherwise, you may need a vacuum resivoir or even a pump. or you could go with hydroboost which runs off power steering pressure.
you need a good source of manifold vacuum to run the booster, a hose, and a check valve (which should come with the booster)
i have not done this swap, but i know you will need to take the pushrod off your old master if you want to use it. you may need longer lines from the master, as it will be further from the firewall. the stock style booster uses the lower hole in the pedal for its rod. this may make the pedal lower. if so you will need a bracket to activate the brakelight switch. i dont know if this is one to lower the switch, or one to come off the pedal and hit the switch in its current location. some people have just extended the rod to bring the pedal up to hit the switch. there may also be a gasket on the firewall which has to be removed for proper booster mounting. the booster needs the proper length pushrod on the outside to fit the master. there are 2 lengths. you will probably need the long one with your current master.
cant think of anything else offhand. if you swap to power drum, you can use the same booster with a different master if you then switch to disc brakes.
i too may eventually put a booster on my car, and i'll see how accurate my info is. i still need to put my disc brakes on first... after i install lower gears....
There are factory style, new reproduction boosters being sold on ebay for about $150. The come with both pins and the pedal rod and clevis.
There's nothing to modify on the firewall. There are four studs there and the master is mounted to two and the distribution block to a third. The booser will use all four.
Your manual master will require the long booster pin and as sixstarved pointed out, the pedal rod goes in the lower hole. You should be able to adjust the clevis on the rod to bring your pedal to the correct height and should have no problems with the brake light switch, except for adjusting it.
You probably won't have enought length on your brake lines to move the master to its new location. This will likely be your biggest hassle.
Hey i just went through changing my car to power disc brakes, i was able to pick up the whole set up off of a 70 monte carlo, which included the spindles, booster, master cylinder and proportioning valve, which fit in perfectly,,,,if you do choose to do this switch, you can get all the parts off of a few different gm vehicles that will all bolt up, i believe it is something like 67 to 69 firebird or camaro, 70ish monte carlo, possibly some nova years too i think, don't quote me, maybe someone else can help me out with what exactly will fit??? but it was very cheap to get the setup, so maybe think about used parts
but in all, it went very smoothly, and im very glad i did it!
I go with the used parts too. The last Firebird that I converted I used all 69 Chevelle parts. The best part about the used parts is that it's not so obvious that you converted.
