fitted a new brake pipe of which the last one corroded and burst, all the other pipes look fine and new, whilst bleeding the brakes, once the brake pedel was touched the engine would make a different noise (I no they always do a little) and then smoke would come out the inlet manifold, but when the brake pedel was let of the noise and smoke stopped.
somehow I think brake fluid is getting up into the inlet manifold, going to check the hydrovac, if that's ok what else could it be?, regards bill.