Especially with older cars featuring high-lift camshafts, braking problems have a lot less to do with the brakes than you’d think.
Q. I just recently purchased a 1968 Camaro with a very radical engine in it. The problem is the car is “fast as stink” but doesn’t stop. The brakes have been upgraded to 4-wheel-disc but the brake master cylinder looks original and it doesn’t have power brakes.
I thought the car would stop better if it had power brakes, so I purchased a power brake booster. I had it installed and it is worse, now the brake pedal is hard and I almost need to use both feet to stop the car. Someone told me about getting a hydraulic power-booster that runs off a power steering pump. What do you think?
I’m not sure if your have this type of hot-rod performance expertise, you generally have answers to everything.
A. I’m not much of a hotrodder. I’m more of a junkyard engineer. I would start by finding out what manufacturer brakes you are using. Once you know the manufacturer I would contact them for the proper master cylinder and proportioning valve components. The matching parts will make sure you have all of the hydraulic pressures correct.
After that, it’s time to move on to the power booster. The low assist is most likely due to the low engine vacuum from the aggressive camshaft in your engine. I remember seeing high-performance engines running as low as 8 or 9 inches of vacuum, which isn’t nearly enough to keep a vacuum power booster working correctly.
Here’s a tutorial on how vacuum boosted power brakes work:
A hydraulic power booster can work. Years back GM used hydro-boost, although that system had problems as the system aged. Rather than trying to use a hydraulic power assist conversion, to me a cleaner solution is to use a vacuum pump. I have seen some of these vacuum pumps like those available from MPBrakes.com that are reasonable sized, quiet, although not cheap, but when hidden keep a stock looking appearance to the brake system.
Unlike the power steering based systems, you don’t need to worry about leaking hydraulic lines and losing pressure when making quick turns while using the brakes.