Schrader tire gauge repair

[Redbird]

Has anyone taken one of these gauges apart? I can unscrew the head and that is about it.

 

[Mad Mac]

Mine was frozen with rust so I left it in diesel for a couple of months. Finally managed to dismantle it, but don't have the spare parts to repair it.

 

[Redbird]

What is inside?

 

[BILL WILLIAMSON]

What is inside?

A slide scale & a spring.
Bill W.

 

[Dick So. Cal.]

I just replaced the o-ring and mine works just fine.

Dick

 

[Bob/AZ]

Mine is like the upper one in Redbirds post. The sliding scale is free but it didn't work so I decided to try to replace the gasket material where it contacts the tire Schrader valve. I dug the old stuff out and it was more like a fiber material than rubber. I cleaned it up down to bare metal and there are two metal washers at the bottom. One of them is sort of a flat cup shaped washer which I assume the gasket sits in. I tried O-rings with no luck so I punched out a 1/8 inch thick rubber washer of a diameter which fills the area and I then punched a hole in the center which fits around the post. Now when I put it on a tire Schrader valve it only slightly moves the gage out. Has anybody rebuilt one of these?

 

[Redbird]

Thanks for the info so far. After you unscrew the head there is a disc of some sort with a hole in the center. Anyone get that disc out w/o destroying it. I can give both a hard shake, like shaking down a thermometer, and the indicator comes out. I don't know what kind of spring, as Bill indicated, would be in there.

 

[Redbird]

I just cut a slice mark on the disc and got it out, and a piece of a round gasket. down the center is a rubber liner of some sort that came apart from age. A camera shot down the middle still shows part of the liner. I think I can see a frozen/rusted up spring. I am going to soak in Evaporust over night and see what else I can take out.

 

[Bob/AZ]

I didn't want to mess with that disc since I didn't think I would be able to replace it but I'm thinking my problem might be under there also. A rebuild kit for these would be the answer but for a low dollar item I don't think that's gonna happen.

 

[Redbird]

I got it apart! After soaking overnight, the order of disassembly is: unscrew the head, remove the disc with the hole in it (had to cut a slice in it w/ razor knife), with a large screwdriver back out the spring assembly, remove the "scale" cylinder. The spring was very rusty, so back into the EvapoRust.

 

[Redbird]

Both ends attached to the spring unscrew. There is a thin rubber membrane capped at one end, and open toward the nozzle head. I used the end of a pencil to push it out. It was a little rotted and broke. The spring is back soaking since a few of the windings on the spring were rusted together.

 

[Bob/AZ]

Great pictures Redbird. Now I can see how the thing works. Do you have any ideas on what you might use to replace that membrane?

 

[Redbird]

I got them both to work, by cutting out a disc from carb gasket material, and cut off a finger from a sterile medical glove to use as the membrane. Work very slowly while disassembling and reassembling.

 

[katy]

I got them both to work

How are they for accuracy?

 

[Redbird]

So so on accuracy!