Re: 1956 clipper custom constellation - fuel pump

Posted by HH56 On 2014/6/15 20:00:15

55-6 Packard used the single action pump for fuel only. The aux vacuum for wipers was supplied by a vacuum pump located on the bottom of the oil pump in the crankcase. The vacuum line from that pump exits the block on passenger side about mid point in the block just above the oil pan. It elbows toward the rear for a short distance & into a check valve. Continues out of the check valve almost to the firewall and then bends up to a point about even with the top of block. The main vacuum line exits the base of carb and goes along the side of head toward rear of engine. There are a couple of clamps which use existing holes in the head and in the block to anchor the steel lines. Both of those lines transfer into rubber hoses which go to a balancing valve located on the firewall a few inches below the wiper motor. The port on large end of the balancing valve goes to the motor and the other port on small end is either capped off or goes to the windshield washer if the car is equipped with that option. The washer installation info in the accessories section of SM shows the balancing valve.

If the car has had the original oil pump replaced with the PI reworked pump that was popular several years ago then the vacuum pump has been removed. In that case you would need the dual action pump to have a backup source for the wipers. About the only way to tell if the pump has been removed is to see if the line is still intact and if there is vacuum present when the engine is running.