Rebuild a front axle engagement air valve?

The problem item is the front axle engagement switch on the dash. I've got one that just keeps hissing air out both side holes and through the front (around the lever).

I've taken it apart and cleaned both the piston and the valve body and replaced the o-ring on the piston. Still, no joy.


Hooked up my shop air compressor to the input line to the t-case, so I could hear the transfer case to front axle cylinder engage when I pulled the trigger on the air hose. And it makes an audible clank. So I'm pretty sure that much is working.


Has anyone here been able to successfully rebuild one of these air switches?


Failing that... is there a commercial equivalent I could use, instead? Or something that wouldn't be terribly hard to modify?

They don't cost all that much and you can find a comparable switch at NAPA. I'd just swap it for a new one.

I haven't been able to find an actual military switch anywhere aside from as part of a complete NOS air conversion kit.

Could I trouble you for some nomenclature so I can look it up on NAPA? Until you mentioned that, I was thinking I'd have to go to home depot and just try to find some kind of inline open/close valve.

You can successfully rebuild them.................. there are 2 o-rings in them that you can replace.

Except-the rear valve. It's like a brass disc that is coated with rubber on the side facing the housing. When the front axle is disengaged, the rubber side is pressed against the housing and doesn't let air pressure into the housing. When you throw the switch to engage, the lever pushes the disc towards the firewall, allowing air pressure to get into the housing and travel to the transfer.

Guess what happens to the rubber on that disc? Gets stiff and won't seal properly.

I looked the other day on SS for a civvy cross reference part # for a customer's truck that had a leaking switch. Didn't see one, bought a switch on eBay cheap but it came from Italy so I had to wait (yes, with shipping, it was still cheaper to buy it from an Italian parts supplier than an American outfit).

TexAndy said:

I haven't been able to find an actual military switch anywhere aside from as part of a complete NOS air conversion kit.

Could I trouble you for some nomenclature so I can look it up on NAPA? Until you mentioned that, I was thinking I'd have to go to home depot and just try to find some kind of inline open/close valve.

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The military calls it "Valve Linear Directional Control" - P/N (19207) Manufacturer part # 10924753, Federal Stock 4820-00-832-8077.

clinto said:

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I looked the other day on SS for a civy cross reference part # for a customer's truck that had a leaking switch. Didn't see one, bought a switch on eBay cheap but it came from Italy so I had to wait (yes, with shipping, it was still cheaper to buy it from an Italian parts supplier than an American outfit).

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It's called Bendix 229635X TW-1 Lever Operated Control Valve. See it here in their catalog, page 38.
That is the correct one and it can be bought online, several options...


G.

I did successfully rebuild my valve/switch a few years back. The O-rings were wore out, I replaced them, and reassembled. It's worked fine since. Are you sure the valve body isn't cracked?

I don't have a Napa part number but I've got a civilian truck with a air tag axle. It takes the exact same switch to control the tag axle that the deuce uses for the air shift t-case. I just had to replace said switch awhile back and Napa had it in stock.

Just take your old one off and take it to Napa and they should be able to match it up.

Thanks guys. Looks like this is far more available than I had previously thought.

I had the same problem as you. replaced the orings as you. Still had the problem. As clinto said, it was the rubber on the disc that was too hard to conform to the seat and seal properly. I scraped off the rubber, cleaned the disk well, and made a new rubber out of bicycle inner tube, and glued it on with 3-M weather-strip adhesive. It now works fantastic!!!. The time to do this was one beer.

I must have an older version or something.

When I take mine apart, there's literally just a pison with a single o-ring on it and a tapered spring. No second o-ring or disc with rubber backing. I'm not even sure where the second o-ring would go. There's only one o-ring groove on the piston.

TexAndy said:

I must have an older version or something.

When I take mine apart, there's literally just a pison with a single o-ring on it and a tapered spring. No second o-ring or disc with rubber backing. I'm not even sure where the second o-ring would go. There's only one o-ring groove on the piston.

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Sounds like you're taking the front apart. Look on yours on the back (where the red arrows are in the picture below) and see if you can remove the fitting.

Yeah, I removed the fitting. I never saw a washer or disc like yall are describing. Either in the fitting or in the body. I'll bet that's my issue.

I ordered an NOS from a guy on ebay. When it gets here I'll see what that piece looks like. Maybe I can take a hardware store washer that is close to the correct size and finish it on the lathe. Then back it with a piece of viton or something.

Hm... it IS a little bit different, but it should work.

Came in a box labelled "Newstar S - 5676. Replacement for : 229617 229635 KN-20001"


Looks like a cast Zamak alloy body. The adapter nut in back is steel.

Haven't taken it apart yet, but it looks like there's a second spring in the back beneath the adapter nut as well as the disc ya'll were talking about.

I'll take it apart and post side by side comparison pictures later.

TexAndy said:

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Came in a box labelled "Newstar S - 5676. Replacement for : 229617 229635 KN-20001"
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Newstar....? ... good luck!
(Didn't you say you ordered a NOS valve???)


G.

That's what I thought I was getting. I guess we'll see if it works or not.