VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 53 235/PG stuck heat riser

Hello,just my second post here.I just bought this car and know very little about this era,not sure I made the right choice regarding model/body style,but,what's done is done.The car starts fine cold but it needs coaxing when it's warm.I figured I would have a look and lo and behold,the heat riser is frozen.Are there any ways for me to persuade this riser to work again.Thanks in advance for the input.

There are several ways but the first thing I would do is-
Pour a good amount of ATF or Marvel Mystery oil thru the carburetor with the engine running and cold.The oil will flood the exhaust and the inner shaft area of the heat riser.Then lube the exterior area of the shaft with PB Blaster penetrating oil.Its one of the few that "work".After a good soaking tap the heat riser with a hammer from front to back-back to front, to try and loosen it up.Do not try to turn.If this dosen't work lets us know.
When the bottom of the weight is perfectly horizontal the heat riser valve is in the cold engine position.When turned about 30 degrees it in the hot position....Good Luck

Very good advice. Could you put some of the ATF in before starting the engine to allow it to settle into the rizer area before running the engine and them do exactly as above? Maybe that is not good, but its more of a question.

My heat rizer valve is stuck but my manifold is off the car now any advise for that one?

The same thing worked for me with the manifold off the car, I soaked it with PB Blaster inside and out a day or two and tapped the shaft sideways back and forth gently and with patience it freed up, the old spring even loosened up and worked.

all the comments are valid, I used Liquid wrench, soaked the shaft from the outside and rigged up a small hose on one of the straws and dropped the exhaust pipe, sprayed the inside of the heat riser chamber and let it sit for a day or so, repeated and then started tapping, I finally had to make a wrench similar to a strap wrench slipped it over the big end of the shaft and with very sligth pressure while tapping to it freed up. If you remove the spring reinstall per the manual, the spring does not make the shaft move but relaxes as it warms so that the exhause gas can push the damper into the open position.

Here is an update,after following the suggestions by gene,mr mack et all,the heat riser is unstuck!!! I did not hold out much hope for it to ever work again,but,with a little patience and liquid wrench and the ball peen hammer from my tool kit in the trunk of the car,I was able to get it unstuck.I soaked it over three different nights,tapping as I went- eventually it loosened up.The spring still works as well!! Kudos to all of you!! Now I you guys know a way to make the rain go away up here in CT so I can drive the car,that would be fantastic!!! I have owned the car for nearly 3 months and had it on the road twice!! Thanks again folks!

Glad to hear of your success......The rain ended here in Wisconsin yesterday and we will have great Spring weather for the next few days and then send it your way... :) :)

A little rain never hurt a Chevrolet!!