I have just got my 71 442 on the road for the first time since I acquired it five years ago. I am having issues with the brakes, which is disappointing as nearly all parts were replaced. It is acting similar to the brakes on my 71 SX that I always considered to be marginal at best, so a remedy for one could be a fix for both. During the restoration of the 442 I have replaced the master cylinder, booster, combination valve, (all from Inline Tube), front pads, rebuilt calipers, rear shoes, wheel cylinders, drums, hardware, rear axle brake lines and the three flex hoses. The only original parts are the front rotors and the balance of the metal lines. The issue I am having is that on both cars, there is a weak brake response. There is an initial resistance in the brake pedal before it goes down further. It eventually stops, but the pedal seems to be at its maximum travel but you don’t get the feeling the calipers are getting enough pressure to clamp the rotor effectively. On both cars you can push that pedal as hard as you want and in no way will the brakes ever lock the wheels. As I drive the 442, its braking action is getting better as the “newsness” of parts mesh and any residues are burnt off but it remains marginal at best. I can feel the pedal sink a bit as I start the engine and I can get two or so pumps before vacuum is exhausted, so the booster is working. Vacuum with the Comp cam XE262 is around 15 – 17”, which should be adequate. The SX has near 20” of vacuum and it suffers from the same pedal resistance and lack of bite. I used a mityvac to bleed the brakes, and have a good firm pedal. I even did them three times to ensure no air was left in the lines.
On my newer cars, the pedal goes down with no resistance and you get nice feedback in the pedal and the car reacts proportionately to the pedal pressure, but not these Cutlasses.
So, I’m sure these Cutlasses must have the potential to have better braking response. The pedal feels dead and a delay built in. So, I’m wondering if most are able to lock up their wheels if they stomp on the pedal and what could the problem be? Both cars have the brass combination valve. Could something be wrong inside, and if so is there anything that can be done with them? The 442 one is brand new. Does the little button behind the rubber cap have any bearing on this? I’d really appreciate any insight on this problem and would be interested to know if others had similar problems. Thanks for any responses.