Air Shut-Off Damper ?
 

Does anyone have a good picture of the air shut-off damper that goes in the cowl on A/C trucks ? I'm looking for how the spring loaded pin goes into the firewall. There's a hole about 1/2" and the spring loaded pin is about 1/8. I have the plastic piece that goes on the engine bay side, but there must be something that goes on the other side, a bushing or something ?

Gary

Re: Air Shut-Off Damper ?
 

I found this picture, and it looks like there is a bushing inside the cowl where the pin goes.

Where can I get one of these ?

Gary

Re: Air Shut-Off Damper ?
 

This pic has the part I'm looking for circled

Re: Air Shut-Off Damper ?
 

Anyone ? Anyone have a picture so I could make one ?

Gary

Re: Air Shut-Off Damper ?
 

I think LMC sells that part. If not try one of the many 67-72 vendors or if you're OK with a used used one try the parts board. Even another option is to make one. Pretty simple flanged bushing made from plastic. I had a hard time finding the plastic one on the firewall so I bouight a used one. Good luck!

Re: Air Shut-Off Damper ?
 

I just checked LMC and they do not sell the plastic parts for the AC flapper valve.

Re: Air Shut-Off Damper ?
 

The parts book calls number 4 a BEARING #3895487 and number 3 a CAP #3895486

That's all I got at the moment.

Re: Air Shut-Off Damper ?
 

So far I haven't been able to find one either used or after market. So I guess I'll have to make one ! I'll measure the hole and the spring pin diameters and make one from Teflon or nylon, something like that.

Gary

Re: Air Shut-Off Damper ?
 

I ended up making one from a nylon bolt from Ace Hardware. Quick and cheap.

Re: Air Shut-Off Damper ?
 

Well I tried using a plastic fitting but it broke, so I used a brass fitting and machined the hole over sized and left a shoulder on the inside and inserted a piece of nylon tube as the bearing.

Re: Air Shut-Off Damper ?
 

One more with the damper installed.

Re: Air Shut-Off Damper ?
 

Before I too machine one does anyone know of a source for a correct oem nylon bushing?

Re: Air Shut-Off Damper ?
 

I can not fine any. I need the front one on the firewall. My back one is OK shape, but front is burnt up bad.

Re: Air Shut-Off Damper ?
 

Sorry to our knowledge neither nylon bushing is reproduced. Anyone with a 3D printer. Brass fitting idea was ingenious in my opinion kudos for thinking outside of the box.
Paul Jr @ GMCPauls

Re: Air Shut-Off Damper ?
 

Paul
I will have a big order for you pretty soon. Guess I'll have to make one of stock. I don't have access to 3d printer. Thanks for input.

Re: Air Shut-Off Damper ?
 

Might check the Hillman drawers at one of the big hw stores or McMaster Carr for a nylon "hat", seems like a common type of uncommon item

Re: Air Shut-Off Damper ?
 

Funny there is a nice repop of the damper and the vacuum actuator but no one makes the bushings. My brother made them for me out of Delrin.

Re: Air Shut-Off Damper ?
 

IF anyone can post the dimensions, I could print some...once I upgrade my hotend to work with nylon