Packard Forum Index » V-8 (1955-56)

Long time since I had vacuum wipers and was just wondering if anyone is using their vacuum wipers with the PI (and others) modification that removes the vacuum pump. Am thinking of going back to stock for the looks and wondering if any issues big enough that would warrant a different or second source?

Those that had the PI-modified pump installed and retained the stock vacuum wiper motor had best results by installing a dual-action fuel pump to take the place of the unit formerly driven by the oil pump.

I suspect they took a cue from the Hash implementation.

HH56. U currently have a PI pump and electric wipers????

I'm running the Olds conversion oil pump ergo no vac pump. Retained the factory original vac wiper motor. The PROBLEM is pulling long hills using only engine vacuum. The wipers will stop. Short hills not a significant problem.

My recommendation is stay with the electric wipers if that is what u have. OR, go with an electric vacuum pump or a constant drive vacuum pump from a diesle and run it off of the fan belt.

That's what I have, and also what the concerns are about. I seem to remember the vacuum wipers quitting when tromping on the gas which is the way I seem to recall was the usual state when going anywhere--and that was with the regular fuel pump setup on the 51 I drove during school. Of course, there is nothing saying the vac pump section was working then either so my memories may be biased. Was just curious if anyone was doing what I contemplate.

O-D must be influencing me with the authenticity part and after someone --I believe it was Jeff --had his repaired and working well the vacuum looks so much more appropriate.

I would follow Brian's suggestion and try to find a Dual Action fuel pump. That's what all the '54 and previous car used for the wipers generally.

The problem with dual action is that it would not be Hoyle, or legit or what ever term the clubies use. So it would be trading a legit wiper motor for an illegit pump.

The electric vacuum pump hidden away somehere wou,ld most likely do the trick. The only problem is the electric vac pumps are rather expensive. I have a medical vacuum pump here (can't remeber the med term for it) used for pumping out stomachs but it is 110ac. I'll take a look at it to see how much triouble it would be to convert to 12v. Not sure it is strong enuf tho.

The dual action fuel pumps are only good for about 20K miles or so. Or that's all i could ever get out of them.

I looked into the electric pump from Summitt a few days ago and they're about $250 when all done. More than I would spend just for wipers. I have a 12v tire compressor which might be able to be replumbed. Have done that on a couple of regular compressors that I used when I did my own AC work a while back so that was the way I was leaning if the consensus says a second source is a good idea.

I've tried to convert the 12v electric tire pumps to vacuum. THey just won't pull enuf or fast enuf for the wipers.

Some of the 80's something 4 cyl. puddle jumpers used an electric vacuum pump for the power brakes. Also some RV's.

Packard flet a second source was a good idea - enough that they added he balacing valve and vac pump piggybacke off the oil pump. The idea behind it all was that as egnien demand increased, manifold vacuum feel off, but as engine RPM increased, vacuum generated by the oil pump set-up would increase.

AM engineers opted for their own oil pump for the Packard V8 isntallation, sans vacuum pump, but also used vacuum-driven wipers motors. Apparently they liked the balancing valve idea, but turned to a dual-action fuel pump. a 20OK lifespan doesn't sound too bad on a car that isn;t driven on a daily basis, yet I wonder if that's due to tired old rubber. As BigKev showed us in his article, the dual-action pumps aren't terribly hard to rebuild.

As for authenticity, I've seen more than one V8 Packard at a show that was refitted with dual-action fuel pump to accomodate for reatined vacuum wiper motor when the PI-modified pump was added. Again, I've no doubt the idea was inspired by the Hash implementation.