Hi there, I have found that after 2 pushes on the brake pedal in a row while driving the 3rd one is rock hard. The brakes worked fine with the TB42 petrol engine in it, the booster worked fine. Since I put the TD42 diesel engine in it with the vacuum alternator & a little bigger than factory vacuum canister with the one way valve the brakes are nowhere near as good. Is this common with alternator boosted brakes ? I have four wheel disc brakes off a EFI GQ, with a new master cylinder. Cheers Grant.