My LJ XU1 is fitted with a bathurst spec race cam (according to my mate who I bought it off - engine built by Bill MANN Brisbane ) and as it was sitting for 20 years unstarted when I got it this year, I had the brakes and master cylinder reconditioned and then started it but I appear to have minimal power assist brakes particularly at idle.
The car is not registered yet so can't take it for a drive, but I was told to test the XU1 booster for faults, pump the pedal several times then keep the pressure on the pedal and start the car and the pedal should depress when the engine starts. When I did this the pedal depressed about an inch or so after the car started.
Apparently that indicates the booster is working ok. Whilst the car is idling I pump the brakes several times and the revs increase. I also assume this means the vacuum is working. I checked the original albeit hard vacuum hose from the booster to the engine and its from 1972 but still seems to be sealing. I've only backed it out of the driveway and back into the garage and the pedal feels like there is no power assist. A reliable mechanic mate says that cars with high lift cams have no vacuum hence why the brake pedal feels hard. He also said that GTHO fords had the same problem but Ford fitted a vacuum cannister specifically for this problem at idle.
Do any of the forum member have this problem?