Author Topic: Moisture in gauges - how to clean inside glass  (Read 212 times)

Online richard5933

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Moisture in gauges - how to clean inside glass
« on: September 12, 2019, 02:40:56 PM »
A couple of my gauges seem plagued with moisture in them. There is no leak, and no water entering the gauges from outside. There was a small windshield leak last year, but that has long since been fixed.

Every since, on humid days or on days with big temperature swings, moisture accumulates inside the glass on two of the gauges. There is also a bit of build up on the inside of all the gauges which creates a bit of difficulty seeing them clearly at night.

Any way to open the gauges to clean the inside of the glass? Any direct replacements for these gauges without having to swap out the sending units?

The oil pressure gauge at the bottom left is the worst of them.

Richard
1974 GMC P8M4108a-125 (Custom Coach "Land Cruiser")
1964 GM PD4106-2412 (Former Bus)
Located in beautiful Wisconsin
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Offline Geoff

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Re: Moisture in gauges - how to clean inside glass
« Reply #1 on: September 12, 2019, 04:08:43 PM »
Hair dryer.
Geoff
'82 RTS AZ

Offline chessie4905

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Re: Moisture in gauges - how to clean inside glass
« Reply #2 on: September 13, 2019, 02:43:26 AM »
Remove and place in a jar of rice. Reinstall. Move on to the next issue. If you don't  like that suggestion, place a dehumidifier in coach and set it at constant on till the moisture leaves.
« Last Edit: September 13, 2019, 02:45:45 AM by chessie4905 »
GMC h8h 649#028 (4905)
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Offline chessie4905

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Re: Moisture in gauges - how to clean inside glass
« Reply #3 on: September 13, 2019, 05:53:37 AM »
When the gauges are manufactured, a machine rolls the edge of face ring so the edge folds around the gauge case. No way to remove that ring without destroying it. They probably arent 100% sealed anyway because of hole for illumination lamp.The other issue is the dash ac. It chills all the metal gauges and when they warm up, they draw in moisture. Maybe removing and placing into a container of rice for a day or two, the problem will go away.
« Last Edit: September 13, 2019, 05:55:36 AM by chessie4905 »
GMC h8h 649#028 (4905)
Pennsylvania-central

Offline chessie4905

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Re: Moisture in gauges - how to clean inside glass
« Reply #4 on: September 13, 2019, 05:59:13 AM »
After doing this, go with brighter bulbs or find a proper brightness led rated for 12 to 36 volts.
GMC h8h 649#028 (4905)
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Offline Jim Blackwood

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Re: Moisture in gauges - how to clean inside glass
« Reply #5 on: September 13, 2019, 08:43:15 AM »
A little backwards, when the gage cools it sucks in air. Probably the water got in during the leak and has never left. It needs persuaded.

Jim

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Offline Van

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Re: Moisture in gauges - how to clean inside glass
« Reply #6 on: September 13, 2019, 10:50:55 AM »
If the case is made of plastic score around it carefully using an Xacto knife, take apart clean the glass with lens cleaner. reconnect the housing with JB Qwik weld. While you have it apart update the bulb holder to accomidate a more modern bulb socket. I did this with the gauges in my Eagle, worked great!
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Offline chessie4905

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Re: Moisture in gauges - how to clean inside glass
« Reply #7 on: September 13, 2019, 12:41:15 PM »
It would take one heck of a leak for it to get into the gauge. Flood? Probably caused by cold air from under dash blowing, unless leak was dripping on gauges. Just pull and put it in the rice. The factory gauges are metal, not plastic.
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Offline windtrader

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Re: Moisture in gauges - how to clean inside glass
« Reply #8 on: September 13, 2019, 10:10:38 PM »
If you can safely drill a hole in the gauge case, insert some desiccant material, then tape the hole. If it pretty bad, maybe repeat if it seems to be working.
Don F
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Offline chessie4905

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Re: Moisture in gauges - how to clean inside glass
« Reply #9 on: September 14, 2019, 04:16:45 AM »
The rice will draw the moisture out the hole that the illumination lamp snaps into. This works fine for cellphones that get wet.
Oops, I forgot to mention to use UNCOOKED rice.🙄, and minute rice wont do it faster.
GMC h8h 649#028 (4905)
Pennsylvania-central