[GMCnet] What did this GM vacuum pump originally come on?

[Bob Dunahugh]

I bought it at a GMCMI event. My problem is that I didn't think about the fact that the wiring plug wasn't there. And I don't know what it came on to find out how to wire it. The 4 terminals are labeled A B C D. The part number on the end is 5048679. There are two ports. With one labeled outlet on a funnel shaped piece. Does the outlet port go to the brake booster?
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[Thomas Phipps]

Bob, Can you put power to it and identify which port performs which function? Perhaps a photo might help someone identify it from men's mall shopping
trips.
Tom, MS II
--
1975 GMC Avion
KA4CSG

[Emery Stora]

Bob
That is a pump that many of us used a few years back.
They can be found on the following vehicles (it is
hid under the battery tray on the
drivers side)
Buick Skyhawk (Body style J) -1982
Buick Skyhawk (Body style X) - Years 82
Chevy Celebrity (Body style A)  Years 84-86
Chevy Caprice (Body style B) 1982
Chevy Cavalier (Body style J) 1982
Chevy Citation (Body style X) Years 82-85
Olds Cierra (Body style A) 1986
Olds Firenza (Body style J) 1982
Olds Omega (Body style X) Years 82-84
Pontiac 6000 (Body style A) Years 85-86
Pontiac J2000 (Body style J) 1982
Pontiac Phoenix (Body style X) Years 82-84

I found that it was also used by Volvo volvo --760-GLE TURBO (GAS) --1985 and 1987. Thet are located under the hood riht on top of the engine on the driver’s side.

If you can find one of the old cars you should be able to get the plug you need. You want the suction port to go to the booster and the other (I assume it would be called the outlet) to the manifold on the engine.

One problem with this pump is that it really doesn’t put out enough vacuum for the GMC motorhome.
I switched to the Long pump which was from a Ford electric car (Azure) but that pump is no longer available. That pump puts out a lot more vacuum.

Emery Stora
>
> Bob Dunahue posted:

[Emery Stora]

That should have read "Lenzi" pump, not "Long" pump.

Emery

Begin forwarded message:

[Bruce Hart]

Bob,
As luck would have it you can build your own connector;-)

Napa #s
725267
https://www.napaonline.com/napa/en/p/NW_725267/NW_725267
725170
https://www.napaonline.com/napa/en/p/NW_725170/NW_725170
725152
https://www.napaonline.com/napa/en/p/NW_725152/NW_725152

http://gmcmotorhome.info/figs/vacpump/vac.html

This is what you were looking for:

Connection A (Red wire) battery positive, 12 volts+ through a fuse.
Connection B (Black with white stripe) ignition positive, 12 volts+
Connection C (plugged) not used (not used in factory system either)
Connection D (Black wire) ground, 12 volts-

[Bruce Hart]

Forgot to include this note:

Try to use multi stranded wire as a single wire is very stiff.

On Fri, Feb 24, 2017 at 7:14 PM, Bruce Hart <hart...@gmail.com> wrote:

> Bob,
> As luck would have it you can build your own connector;-)
>
> Napa #s
> 725267
> https://www.napaonline.com/napa/en/p/NW_725267/NW_725267
> 725170
> https://www.napaonline.com/napa/en/p/NW_725170/NW_725170
> 725152
> https://www.napaonline.com/napa/en/p/NW_725152/NW_725152
>
> http://gmcmotorhome.info/figs/vacpump/vac.html
>
> This is what you were looking for:
>
> Connection A (Red wire) battery positive, 12 volts+ through a fuse.
> Connection B (Black with white stripe) ignition positive, 12 volts+
> Connection C (plugged) not used (not used in factory system either)
> Connection D (Black wire) ground, 12 volts-
>

--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class

[gene Fisher]

Read here
http://gmcmotorhome.info/addens.html#jc4

Read the whole story

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[Bob Dunahugh]

PERFECT. THANK YOU SO MUCH gentlemen. I'm on a mission that if I got it around. Get it on. Thus not getting lost, and off the shelf. Bob Dunahugh

[poww...@gmail.com]

These Vacuum were lasted used in the Mid 1980’s. They are still available on the models listed in the Supplemental vacuum pump list. Having search the men’s malls you have to be careful. I have found that you will have a 50/50 chance to find a working pump. The diaphragms have had a high failure rate. Remember that most are more than 30 years old.

J.R. Wright
GMC GreatLaker
Newsletter Editor/Publisher
Tech Editor
78 Buskirk 30' Stretch
75 Avion Under Reconstruction
Michigan

[John R. Lebetski]

Gotta say that's some perfect examples of great information networking including what it was used on and the Pinout.
--
John Lebetski
Woodstock, IL
77 Eleganza II

[Pete Smith]

"I switched to the Long pump which was from a Ford electric car (Azure) but that pump is no longer available. That pump puts out a lot more vacuum.

Emery Stora"

Could you run two of the GM ones in parallel? Twice the vacuum and maybe redundancy as well?

Pete




--
Cary, NC

No Coach yet but likely center kitchen, dry side bath Royale, 78, 403, hopefully with good original white Imron paint.

[Emery Stora]

That would help the recovery time but the extra degree of vacuum, about 3" more vacuum, gives more braking so two pumps would not give a lower vacuum than one pump

Emery Stora
77 Kingsley
Frederick, CO

[Ken Henderson]

IMHO, the way to use the old GM vacuum pumps is to install them between the
engine and a vacuum reservoir (30" of 4" PVC in the rear of the #1 front
crossmember), with that reservoir supplying vacuum to the booster.

That way, the vacuum stored in the booster, and another 3 applications in
the reservoir, will begin at the highest vacuum last created by the engine
during deceleration, but never lower than what the pump is capable of
creating.


Ken H.

On Sat, Feb 25, 2017 at 10:54 PM, Pete Smith <psmi...@nc.rr.com> wrote:

>
> Could you run two of the GM ones in parallel? Twice the vacuum and maybe
> redundancy as well?
>
> Pete
>
>

[gene Fisher]

But only good for one pump.
On Sun, Feb 26, 2017 at 4:43 PM Ken Henderson <hend...@bellsouth.net>
wrote:

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[Johnny Bridges via Gmclist]

By test, my reservoir is good for three stops with no engine. Since the NO is going to hook up the power to the pump, we'll have to ask him how it
does with the pump running. I suspect it will keep you from hitting things.

--johnny

NO = New Owner
--
'76 23' transmode Norris upfit, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"The road goes on forever, and the party never ends" --Robert Earl Keen