Stuck Heat Riser ?

[Guest]

50 - 53 263 straight 8. The heat riseer is stuck. I don't want to break the cast iron. I don't want to go caveman on it.<BR>I have taken it off the engine and soaked it it liquid wrench.<P>Does anyone have a good system for rebuilding or lossening the heat riser?

[Guest]

i have the same problem. thinking about taking it off and heating it w/ torch.

[BuickNut]

My dad had the same problem with his '52 Super. I stongly suggest using a penetrating lubricant called "PB Blaster", you can get it at a lot of automotive stores, Meiers, maybe Kmart, etc. This is by far the best stuff I have ever used. I would still suggest using a torch as well, but this stuff worked by itself. It might take a couple of days of dousing it really well about 5 times a day....but it worked for us in just 1/2 day. Good luck.

[Guest]

use the penetrating oil as described above. Using a lite hammer LIGHTLY strike the END of the shaft on Both sides alternating from side to side. If u want to apply a little heat to it ok. But usually just striking at the ENDS of the shaft PARALLEL to the shaft will work it back and forth enuf to eventualy loosen it.

[Guest]

CLARIFICATION: What u want to do is move the shaft back and forth PARALLEL to the shaft. That means u will have to strike the ENDS of the shaft. OR to put it another way, u want to move the shaft back and forth parallel to the shaft. DO NOT try to force the shaft radially. DO NOT strike the weight. It will break off if u strike the weight.

[NTX5467]

Once you do get it loosened up and removed, be sure to polish and deburr the shaft so the friction surfaces are nice and smooth and round. If you have a rebuilding kit, there probably would be a bushing to go into the manifold to serve as the friction interface for the heat riser shaft. <P>Once the new bushing is installed (which would apply to the existing bushing if you are just freeing things up), you might need to get an appropriately sized reamer to "clearance" the ID of the hole the shaft will be inserted into. This plus the polished shaft will ensure that there is no binding or excessive friction on the shaft so the thermostatic spring on the heat riser can work properly. It's better to be a little loose than to be too tight. From my experience, if you can't turn it with your fingers and the spring will snap it closed when cold, it's too tight.<P>During reassembly, after making sure the clearances are ok "dry", you might lubricate the shaft and bushing with GM Heat Riser Lube or similar (in a spray can) as it has a certain amount of graphite in it. It's also a penetrant.<P>Just some thoughts . . .<BR>NTX5467

[Guest Dynaflo2]

Lusty 1, you never mentioned whether the riser is stuck open or closed. If stuck closed, you certainly want to get it freed up again. If it is stuck open, unless you drive in cold weather, it won't make much difference. The heat riser on my '51 is stuck open. I have decided to let it stay where it is. I started to try to loosen it up a few years ago, but then worried that if I got it loose that it might get stuck again someday and possibly in the closed position and that would be bad. Just my two cents.