Tach / Vacuum gauges Help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tomatocity · 08-09-2005, 12:18 AM

This last weekend I bought a used tach / vacuum gauge cluster and it looks pretty clean. The bezel had been painted flat black and the lens had normal wear so I bought new ones. I have never separated the bezel / lens / gauges and would like to know what I am getting into.
* the current lens reads AIR PRESSURE and not VACUUM as the new lens does. I included a picture of the original gauge. Is the gauge actually a vacuum gauge but was labeled Air Pressure by GM?
* the only gauge face that is discolored is the tach. I included a pictures where you can see teh rust starting at 35.
* what do I need to do to clean the face of these gauges?
* the needles look surprisingly good. This must have been a garage kept truck.
* are there any parts I need to purchase so I can refurbish this cluster?
* how can I tell if the gauges work? The speedo moves when spun from the backside. The Tach is on '0'. The Fuel is almost half full. The Battery is centered. The Temperature is a little above the first mark. The Air Pressure is '0'. The Oil pressure is '0'.
* all the bulbs look good. Do you think I should replace them anyway?
* what is the best way to clean the printed circuit or should I leave it alone?
* should I use Copper or Plastic tubing for the Oil Pressure guage. I plan on installing another Oil Pressure gauge under the hood.
* where are the Lens Bumpers? Saw them in the Truck Shop catalog.
** I know nothing about refurbishing these gauges so I am open to any information and suggestion you have.

Bob Moore · 08-09-2005, 12:33 AM

That is an air pressure gauge. The vac should read in the 10-12-15-17 range. The air pressure was used in 40/50/60 series trucks.

tomatocity · 08-09-2005, 12:38 AM

Excellent information. There goes another $50 for a Vacuum gauge and I will have an AIR PRESSURE gauge for sale. Any idea what it is worth / sell / trade?

saulgoode · 08-09-2005, 01:09 AM

i got a vacuum i may be interested in trading...Pm me if you're interested

tomatocity · 08-09-2005, 01:19 PM

Thanks for the offer and I might make the trade if I can't find something locally. What do you plan on doing with the Air Pressure gauge?

saulgoode · 08-09-2005, 08:15 PM

If i had an air guage I'd use it to monitor an air bag set up. I got the vacuum guage out of a bigger 69-72 that was in a junk yard.

Later Saulgoode

Bob Moore · 08-10-2005, 12:28 AM

TomatoCity - lens bumpers are little rubber worms about 1/8in in diameter and about 5/8 to 7/8 in long. They are used to cushion the lens inside the bezel without scratching it. Also helps to seal the gauges from dust and dirt by pressure on the lens. The lights are fairly cheap to replace but are also fairly easy to get at when dash is installed in the truck. The factory used brass tubing for the oil gauge but most aftermarket gauges use plastic. I would say its about a tossup.

Good luck - Bob

chickenwing · 08-10-2005, 12:49 PM

Tim come on over, you can take apart a spare I have.

My concern it that you have a 40/50/60 series cluster. I thought I read somewhere that the bezel? was a little bit differant. Will they fit the C-10/20 trucks? Have you tried to just put it in place to check fit?

71swb4x4 · 08-10-2005, 01:25 PM

The bezel that is on that one is off a 10/30 series truck. If it was off a bigger truck the slot for the column would be filled in, so no worries there.
Some of the big trucks had the big V6, so make sure that tach has an '8' on the back. Even if it is for a 6 cylinder you may be able to adjust it to work with a V8.

tomatocity · 08-10-2005, 02:00 PM

71swb4x4 thanks for the information about the tach. I will check that tonight when I get home. Maybe this was not such a great deal after all

I just remembered that teh seller had it marked as being removed from a V8. Makes me want to go home for lunch and check the back of the tach.

08-09-2005, 12:18 AM	#1
tomatocity Registered User Join Date: Jun 2005 Location: Sacramento CA Posts: 1,255	Tach / Vacuum gauges Help This last weekend I bought a used tach / vacuum gauge cluster and it looks pretty clean. The bezel had been painted flat black and the lens had normal wear so I bought new ones. I have never separated the bezel / lens / gauges and would like to know what I am getting into. * the current lens reads AIR PRESSURE and not VACUUM as the new lens does. I included a picture of the original gauge. Is the gauge actually a vacuum gauge but was labeled Air Pressure by GM? * the only gauge face that is discolored is the tach. I included a pictures where you can see teh rust starting at 35. * what do I need to do to clean the face of these gauges? * the needles look surprisingly good. This must have been a garage kept truck. * are there any parts I need to purchase so I can refurbish this cluster? * how can I tell if the gauges work? The speedo moves when spun from the backside. The Tach is on '0'. The Fuel is almost half full. The Battery is centered. The Temperature is a little above the first mark. The Air Pressure is '0'. The Oil pressure is '0'. * all the bulbs look good. Do you think I should replace them anyway? * what is the best way to clean the printed circuit or should I leave it alone? * should I use Copper or Plastic tubing for the Oil Pressure guage. I plan on installing another Oil Pressure gauge under the hood. * where are the Lens Bumpers? Saw them in the Truck Shop catalog. ** I know nothing about refurbishing these gauges so I am open to any information and suggestion you have. Attached Images __________________ Got bored, sold everthing. Got bored, looking for a 1960-66 C-10. Want to build my last truck.

08-09-2005, 12:33 AM	#2
Bob Moore Registered User Join Date: Feb 2004 Location: Tacoma WA Posts: 1,365	That is an air pressure gauge. The vac should read in the 10-12-15-17 range. The air pressure was used in 40/50/60 series trucks. __________________ 67 C-20 LWB, tilt, speed alert, vac, 454, T400 67 C-10 SWB, factory air with more to follow

08-09-2005, 12:38 AM	#3
tomatocity Registered User Join Date: Jun 2005 Location: Sacramento CA Posts: 1,255	Excellent information. There goes another $50 for a Vacuum gauge and I will have an AIR PRESSURE gauge for sale. Any idea what it is worth / sell / trade? __________________ Got bored, sold everthing. Got bored, looking for a 1960-66 C-10. Want to build my last truck.

08-09-2005, 01:09 AM	#4
saulgoode Registered User Join Date: Dec 2003 Location: Houston Posts: 388	i got a vacuum i may be interested in trading...Pm me if you're interested Last edited by saulgoode; 08-09-2005 at 01:28 AM.

08-09-2005, 01:19 PM	#5
tomatocity Registered User Join Date: Jun 2005 Location: Sacramento CA Posts: 1,255	Thanks for the offer and I might make the trade if I can't find something locally. What do you plan on doing with the Air Pressure gauge? __________________ Got bored, sold everthing. Got bored, looking for a 1960-66 C-10. Want to build my last truck.

08-09-2005, 08:15 PM	#6
saulgoode Registered User Join Date: Dec 2003 Location: Houston Posts: 388	If i had an air guage I'd use it to monitor an air bag set up. I got the vacuum guage out of a bigger 69-72 that was in a junk yard. Later Saulgoode

08-10-2005, 12:28 AM	#7
Bob Moore Registered User Join Date: Feb 2004 Location: Tacoma WA Posts: 1,365	TomatoCity - lens bumpers are little rubber worms about 1/8in in diameter and about 5/8 to 7/8 in long. They are used to cushion the lens inside the bezel without scratching it. Also helps to seal the gauges from dust and dirt by pressure on the lens. The lights are fairly cheap to replace but are also fairly easy to get at when dash is installed in the truck. The factory used brass tubing for the oil gauge but most aftermarket gauges use plastic. I would say its about a tossup. Good luck - Bob __________________ 67 C-20 LWB, tilt, speed alert, vac, 454, T400 67 C-10 SWB, factory air with more to follow

08-10-2005, 12:49 PM	#8
chickenwing Lovin' Life in Miss.! Join Date: Mar 2004 Location: Puckett, Mississippi Posts: 1,937	Tim come on over, you can take apart a spare I have. My concern it that you have a 40/50/60 series cluster. I thought I read somewhere that the bezel? was a little bit differant. Will they fit the C-10/20 trucks? Have you tried to just put it in place to check fit?

08-10-2005, 01:25 PM	#9
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	The bezel that is on that one is off a 10/30 series truck. If it was off a bigger truck the slot for the column would be filled in, so no worries there. Some of the big trucks had the big V6, so make sure that tach has an '8' on the back. Even if it is for a 6 cylinder you may be able to adjust it to work with a V8. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs. Last edited by 71swb4x4; 08-10-2005 at 01:27 PM. Reason: Spelling, or lack there of

08-10-2005, 02:00 PM	#10
tomatocity Registered User Join Date: Jun 2005 Location: Sacramento CA Posts: 1,255	71swb4x4 thanks for the information about the tach. I will check that tonight when I get home. Maybe this was not such a great deal after all I just remembered that teh seller had it marked as being removed from a V8. Makes me want to go home for lunch and check the back of the tach. __________________ Got bored, sold everthing. Got bored, looking for a 1960-66 C-10. Want to build my last truck. Last edited by tomatocity; 08-10-2005 at 02:15 PM. Reason: text



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