Despair

Posted by Ross On 2012/6/12 16:22:20

56 400 with 55k miles. Just waking it after a too long sleep so all the brakes, fuel system etc etc. have been brought up to snuff. Carb rebuilt, ignition in good shape and a nice new vac advance. Engine runs passable and valve train is quiet.

On the first test drive the brakes were terrible--almost no assist. No wonder--only 6 inches of vacuum that went to ten if you blip the throttle. Also, # 8 had only 60 lbs compression that did not come up if you oiled the cylinder.

OK, so off with its heads for a valve job, and a new timing chain as late valve timing can cause low vacuum. Chain was very slack but it had not jumped time yet.

Buttoned her back up today and went for a depressing test drive. Idles smooth, powerful out on the road, starts nicely--but still only 6 inches vacuum. Timing is set at 10 degrees and there are no vacuum leaks--have tried closing off all connections and spraying around every conceivable gap.

Ideas are earnestly solicited. Can't give it to the customer with not enough vac to assist the brakes.