The Stovebolt Site Forums The Shop Area Engine Shop Manifold heat valve

The heat valve on my exhaust manifold will not turn. Sprayed pb blaster still not moving. It is on a 1956 235
anyone have any ideas on how to free this?

Long process. Keep spraying with penetrating oil and tap (not beat) with a hammer. It may take several days. Others on here have had success so maybe they will put their two cents in.🛠

Yep....been there. It takes a regiment of spraying aerokroil every day. Tap tap tap with hammer. Then a pair of vise grips on the post to wiggle it slightly over time. It works.

Some of them need the application of a a Victor Hot Wrench before they free up.
Jerry

I tried moving the end opposite of the spring. The large balancer I guess. That moves but not the rod it is attached to. Just moved it slightly. I'll keep soaking hope I didn't do damage

if it is stuck in the heat off position, you could probably not even worry about it, Mine had the spring broken off for probably 20 years, I actually had no idea what it was or what it did, the truck just started and ran so well, I never looked for a problem. Even at 20 below zero, it ran like a champ. The little flapper is hardly a tight seal, and the two parts are bolted together so closely heat transfer is quite good anyway. But if it is in the heat ON position, then you will have trouble. But yes if you feel you really need it to work, Just be patient, you will need patience if you are going to work on these trucks anyway.

If the weight is moving, even slightly, that is a good sign. That's usually an early indication that it is about to break free. Use the advice given above plus grab the weight with a large pair of Channelocks and twist in both directions.

They get jammed up with carbon. Sometimes they will free up with the carb and intake installed, sometimes not. If the latter, remove the carb and the intake to get at the inside of the valve. Scrape away as much carbon from the pivot points as you can with a small screwdriver, then hit it with Kroil from the inside and repeat the tapping/twisting procedure described above.

I have had them take over a week to break loose with spraying and tapping a few times a day. Persistence pays off. Usually, you'll first feel a little side to side give when you tap on the shaft, then the weight will start to wiggle. That's an indication that you are in the home stretch.

Good luck,

Matt

The folks above nailed it . I had the same problem and used PB Blaster to free it up. It was not quick or easy, but with a lot of patience ( as in soak, tap-tap-tap with the hammer), soak again....etc, it can be done. It took a couple of days of spraying and letting it "soak" . I found that tapping the ends of the rod worked best for me. Tap left to right, right to left and soak the crap out of it and let it sit. I'm not the brightest, apparently, because I tried tapping up / down on the counter balance weight and bent it down, straightened it back out........
Its free as a bird now. I think you'll get it with that method, if not, there's Jerry's Victor Hot Wrench.

The OP stated that the weight "moves but not the rod it is attached to."
If he keeps torquing on the weight, it will snap something off.

Hey Broke, hear me out.
I ran a '52 with a flapper stuck in the closed position for 20,000 miles without drivability issues. The climate in Virginia Beach, VA is entirely different than Connecticut, but it does get cold enough to warrant having this thing functional.
Even though it ran fine upon startup and throughout the warmup period during cold weather, I am certain that a lot of non-atomized fuel got dumped into the cylinders, washed the oil film off of the cylinder walls and contaminated the oil with gas. Atomized fuel hits the cold intake runner and instantly becomes liquid fuel which does not burn.
That is exactly why GM spent all that extra money designing and manufacturing that intake heating apparatus.
The lack of a functioning heat flapper will reduce the life of an engine. It isn't something which you would notice on a daily basis, but it is happening just the same.
Carl