Combo Fuel Vacuum Pump

[Rainman]

Hey Guys,
I hate to start posting pictures to Fredric's engine rebuild thread, but based on remarks and observations of his vacuum pump made by Rick I thought I'd better repost these pictures. First time I wrote this up it got no attention from anyone. On one of my spare T/O engines before I had to let them go I removed this unusual combination fuel/vacuum pump. The visible numbers seem to match what Fredric is working with. These engines were all early and A1 motors that were never used or modified after they were removed for demill.








That's all I have to say about that (in my best Forrest Gump voice)
Rainman

[Mr. Recovery]

not that I am in any way an expert on this but, the pump in Fredric's photo is a vacuum only pump. The pump you posted is very interesting and I will look for information on it. Thanks for bringing this up again and for the photos.

[199th mp]

i have a combination fuel and vacuum pump on my 66A1, because my in tank pump is disconnected. i don't know if it works, but i'm guessing probably not. the pump i have looks different than yours, and the vacuum is so weak the wipers are essentially useless. i would probably be better served by a new fuel pump in the tank and a proper vacuum pump on the engine itself, but that must be a future project as money and parts become available. i have not learned how to test either one, and electric stuff is my worst area. i still have to find a way to get my gas gauge needle to stop jumping constantly. i have to look in the tank and guess how much gas there is--it's rather annoying.

[Rainman]

Hey 199th,
This do it yourself repair for your sending unit should do the trick.
http://www.g503.com/forums/viewtopic.ph ... nit+repair
Rainman

[199th mp]

thanks for the tip, ray

[ohiomgman]

Hmmmm...so not all M151's, had an in tank electric fuel pump?

[moose53]

Hmmmm...so not all M151's, had an in tank electric fuel pump?

A2's had mechanical fuel pumps instead of the vacuum pump.

Jim

[ohiomgman]

Hmmmm...so not all M151's, had an in tank electric fuel pump?

A2's had mechanical fuel pumps instead of the vacuum pump.

Jim

I am fairly familiar with the differences between an A1 and an A2.

Just betting that the M151's had the "earliest" features (such as no turn signals) and (some apparently had mechanical, dual-action fuel pumps?) while the M151A1's were even MORE different and ALL M151A1's had electric fuel pumps.(?) Just as all M151A2's have mechanical fuel pumps that are camshaft actuated and engine mounted.

[Hambone]

I think I have seen a pump like that on a M715 5/4 ton truck? Hambone

[Rainman]

It's the first and only combo pump I've ever seen on an M151 engine, and probably for most of us. It obviously came out of a motorpool but what it went to is a mystery to me. For all I know the similar base numbers may designate a bolt and hole configuration or a gasket #. Combos would be perfect for lots of guys with the high cost of in the tank pumps. I can dig it out and clean it up to get a better look at all the numbers, but someone ought to be able to ID it here, or heaven forbid on SS.
Rainman

[Fil Bonica]

The 151 engine was used on a Hawk missile carrier.
Could it be from that configuration or from a 38/38A1 engine?

Fil Bonica

[muttguru]

Ages ago, on the G503, I responded to a question that someone asked concerning combination fuel/vacuum pumps.
I'd consulted an expert on M38/A1-M151 engines and took his word for fact. I'd hate to think I'd been sold a dummy

you can see the details here:-

http://www.g503.com/forums/viewtopic.ph ... mp#p761618

Ken