Vaccuum Gage not working - The 1947 - Present Chevrolet & GMC Truck Message Board Network

prg machine · 04-22-2008, 04:22 AM

I found this awesome "Motor Minder " gage off E-Bay It looks like it was never used.
I have it hooked up to manifold ( Performer air gap) but i can't get it to read. any suggestions?

**El Jay** · 04-22-2008, 04:45 AM

I'm assuming you're running rubber hose directly from the manifold to the gauge.
Make sure you are using vacuum hose. It has a heavier "wall" than rubber tubing, so it won't collapse.
Be sure you have the right sized vacuum hose with a good snug fit over the hose barbs.
Don't laugh: If you don't have some kind of a vacuum pump;get a piece of vacuum hose and run it from the gauge to the driver's seat and suck real hard, just to see if you get any kind of needle deflection. If you do have a pump, sit in the driver's seat and try it

Hope that helps a bit.

prg machine · 04-22-2008, 04:53 AM

It is the white plastic tubing that you see in the gauge kits. I can feel vaccuum if i unhook the fitting at the gauge and put my finger over it..... but it is a pulsation rather than a steady pull. I have had these lines come loose on other vehicles before and there is an annoying whistle... I unhooked the tubing at the manifold and don't hear a thing. I have a pretty heavy cam lift and duration. also.

**'68OrangeSunshine** · 04-22-2008, 02:26 PM

If your gauge is OK, you might think about upgrading with copper tubing. It lasts for years.
You might make sure you have no vacuum leaks.

prg machine · 04-22-2008, 03:43 PM

I am suspecting the gauge. But I am not sure if i have enough vacuum. I am thinking about hooking it up to another vehicle with a situation that is working now, that way i can rule out the gauge itself.

prg machine · 04-24-2008, 04:44 AM

I feel kinda dumb...................I checked the obvious today, removed the gauge and looked in the opening behind the fitting on the back of gauge. I found a small screw valve in it. I turned it open 90* sucked on it holding it up to a mirror and it works fine!!!!!! I have no idea what the screw is. All I know is i love the fact this cool looking gauge is now working!!!! Timing and what not is off indicating low vacuum and all of the fittings to gauge are just finger tight as well. I was excited and wanted to take a picture so here it is!!!

ed2552 · 04-24-2008, 06:18 AM

looks cool, call up stewart werner, they may have info on how to tune it or w/e

prg machine · 04-24-2008, 06:37 AM

Yea! I realy like it. it goes real well with the volt meter to the right of it there. The newest retro from SW called the "Green Line" series. see Summit catalog for them. It is almost a perfect match. Now if i get lotsa extra moneys, I may replace the others with "green Line" but not until the rest of truck is finished. I think the other 2 SW gauges i have are pretty awesome as well. The Oil Pressure gauge is fairly old.

prg machine · 04-24-2008, 07:02 PM

I called the experts. The screw is a restrictor I evidently dislodged some oxidation or minor plugging.

Hope this helps any one in the furure.

ed2552 · 04-24-2008, 07:07 PM

So the volt meter is a new one? wow, they match perfectly, by no mistake, i'm sure

prg machine · 04-24-2008, 11:20 PM

Quote:

Originally Posted by ed2552

So the volt meter is a new one? wow, they match perfectly, by no mistake, i'm sure

Yes. The voltmeter is a "Green-Line" re-issue sold by Summit

04-22-2008, 04:22 AM	#1
prg machine Registered User Join Date: Jun 2007 Location: oregon Posts: 1,069	Vaccuum Gage not working I found this awesome "Motor Minder " gage off E-Bay It looks like it was never used. I have it hooked up to manifold ( Performer air gap) but i can't get it to read. any suggestions? Attached Images __________________ 69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears:

04-22-2008, 04:45 AM	#2
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: Vaccuum Gage not working I'm assuming you're running rubber hose directly from the manifold to the gauge. Make sure you are using vacuum hose. It has a heavier "wall" than rubber tubing, so it won't collapse. Be sure you have the right sized vacuum hose with a good snug fit over the hose barbs. Don't laugh: If you don't have some kind of a vacuum pump;get a piece of vacuum hose and run it from the gauge to the driver's seat and suck real hard, just to see if you get any kind of needle deflection. If you do have a pump, sit in the driver's seat and try it Hope that helps a bit. __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck Last edited by El Jay; 04-22-2008 at 04:47 AM. Reason: spelling

04-22-2008, 04:53 AM	#3
prg machine Registered User Join Date: Jun 2007 Location: oregon Posts: 1,069	Re: Vaccuum Gage not working It is the white plastic tubing that you see in the gauge kits. I can feel vaccuum if i unhook the fitting at the gauge and put my finger over it..... but it is a pulsation rather than a steady pull. I have had these lines come loose on other vehicles before and there is an annoying whistle... I unhooked the tubing at the manifold and don't hear a thing. I have a pretty heavy cam lift and duration. also. __________________ 69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears:

04-22-2008, 02:26 PM	#4
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,210	Re: Vaccuum Gage not working If your gauge is OK, you might think about upgrading with copper tubing. It lasts for years. You might make sure you have no vacuum leaks. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not. Last edited by '68OrangeSunshine; 04-22-2008 at 02:28 PM.

04-22-2008, 03:43 PM	#5
prg machine Registered User Join Date: Jun 2007 Location: oregon Posts: 1,069	Re: Vaccuum Gage not working I am suspecting the gauge. But I am not sure if i have enough vacuum. I am thinking about hooking it up to another vehicle with a situation that is working now, that way i can rule out the gauge itself. __________________ 69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears:

04-24-2008, 04:44 AM	#6
prg machine Registered User Join Date: Jun 2007 Location: oregon Posts: 1,069	Re: Vaccuum Gage not working I feel kinda dumb...................I checked the obvious today, removed the gauge and looked in the opening behind the fitting on the back of gauge. I found a small screw valve in it. I turned it open 90* sucked on it holding it up to a mirror and it works fine!!!!!! I have no idea what the screw is. All I know is i love the fact this cool looking gauge is now working!!!! Timing and what not is off indicating low vacuum and all of the fittings to gauge are just finger tight as well. I was excited and wanted to take a picture so here it is!!! Attached Images __________________ 69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears:

04-24-2008, 06:18 AM	#7
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Vaccuum Gage not working looks cool, call up stewart werner, they may have info on how to tune it or w/e __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A

04-24-2008, 06:37 AM	#8
prg machine Registered User Join Date: Jun 2007 Location: oregon Posts: 1,069	Re: Vaccuum Gage not working Yea! I realy like it. it goes real well with the volt meter to the right of it there. The newest retro from SW called the "Green Line" series. see Summit catalog for them. It is almost a perfect match. Now if i get lotsa extra moneys, I may replace the others with "green Line" but not until the rest of truck is finished. I think the other 2 SW gauges i have are pretty awesome as well. The Oil Pressure gauge is fairly old. __________________ 69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears:

04-24-2008, 07:02 PM	#9
prg machine Registered User Join Date: Jun 2007 Location: oregon Posts: 1,069	Re: Vaccuum Gage not working I called the experts. The screw is a restrictor I evidently dislodged some oxidation or minor plugging. Hope this helps any one in the furure. __________________ 69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears:

04-24-2008, 07:07 PM	#10
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Vaccuum Gage not working So the volt meter is a new one? wow, they match perfectly, by no mistake, i'm sure __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A



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