Old Air firewall cover plate problem

[MikeB]

Regarding the firewall cover plate, the instructions say to enlarge the firewall holes to 5/16 and then mount the panel via bolts and its pressed-in studs. However, the holes and studs don't line up with my firewall holes.

I sent a photo of my cover plate to Old Air, and they said it's the correct one for heater-only cab, which is what I have. So I don't know what's going on.

If you have an Old Air system installed on a heater-only cab, please send me photos of your installed cover plate, where the bolt heads are clearly visible. And let me know if you had similar problems.

BTW, the cover plate that came with my 1998 Vintage Air system has the holes in the proper place.

[tim_mc]

Hey Mike, Does this pic help? I don't recall having any issues installing the Old Air cover plate.

~Tim

[MikeB]

Thanks. That's exactly what I was looking for. Looks identical to my cover plate. And your factory firewall holes seem to be in the same location as mine. Looks like you had to drill a few new holes in the firewall, right?

Here's my firewall. Those are my 1998 Vintage Air lines & hoses peeking through the hole.

Edit: Comparing the pictures again, looks like the top 3 holes may line up with my cover plate holes. I need to enlarge a few of those holes, pull out the old unit, and do a test fit. Got a feeling I'm gonna look pretty dumb.

[tim_mc]

Good deal. I don't remember if I had to drill any new holes, or just enlarge existing ones per the instructions. I used some stainless acorn nuts for a more finished look (and fewer sharp edges under the hood).

[MikeB]

Since the rest of my firewall was recently painted when a shop did the entire truck, I'll have to come up with some way to paint the newly exposed areas around the Old Air cover plate. Twenty years ago, I might have pulled the engine and painted the entire firewall to ensure a color match, but not these days. Or if I wanted to spend the money, I could probably find a shop to fabricate a larger plate.

[MikeB]

Hey Tim, are you able to operate the passenger side kick panel vent with the inside AC unit installed?

[tim_mc]

I can't help with that Mike. I made cover plates and sealed up the vents.

[MikeB]

Originally Posted by tim_mc

I can't help with that Mike. I made cover plates and sealed up the vents.

Thinking about doing the same. Have a buddy who's a good fabricator.

Here's what my firewall ended up looking like. Had some red orange spray paint that was a very close match to my firewall.

Those are button head bolts. Will probably use acorn nuts like you did on the two studs that will be sticking out on the left.

[tim_mc]

Looks good Mike! I figured that sealing up the cab vents would help with road noise & dust. I made covers from steel sheet (19ga?) and used some self-tapping screws to install them with a bead of black silicone instead of welding them in.

[MikeB]

Just remembered I have a thick piece of dense foam that I'll try trimming to fit, and use it as a plug. If that doesn't work, I'll order some new seals. I did this in the past on another truck, and it was a PITA drilling out the rivets. But either way will leave the kick panel unmolested for some future owner, probably my son.

I'm not too happy with where the condensation drain hose exits, compared to my old V/A system. Gotta double check my center punch mark and then drill the 1-1/4" hole today. Bought a cheap step drill bit on Amazon because my USA-made Irwin drill set only goes to 7/8".