'67 429: Remove A.I.R. check valve

[Antoni Deighton]

The old (corroded) A.I.R. check valve on the passenger side of my '67 Eldorado needs to be replaced, and I'm trying to remove it but it seems to be corroded solid. I've been using CRC Freeze-Off to try and free the part but it's not budging.

It seems to be a "simple" matter of unscrewing the old valve from the AIR injection manifold. I'm using two wrenches (one on the "nut" on the manifold itself) to try and remove it, but with no luck. I've not tried applying heat yet, but perhaps the only solution is to replace the manifold itself? There's nothing in the Service Manual that offers any help (but then they hadn't been subjected to 40+ years of corrosive exhaust back then either).

Has anyone done this? Any thoughts or comments, please!

Thanks,

Antoni

[Dave Shepherd]

Typical, it is rusted/corroded in their good, as you know, try some heat, may be the only way.

[Antoni Deighton]

Well, I was a bit apprehensive about applying heat, but it worked well. Some gentle heat with a small butane torch, followed by a firm twist and it started moving. Once I got it going it unscrewed easily! Nice to get it done, and I'll be trying that technique again on other stubborn fittings. (Especially since several days of applying penetrating oil didn't do anything.)

By the way, the size of the thread in the AIR injection manifold is the same as a 1/2" gas pipe. A trip to the hardware store got me a fitting to cap it off. (The AIR pump was removed by the previous owner, so until I get another one to install the check valves are not adding anything except preventing backfires!)