My new to me '67 Coronet with a '77 440 is doing something weird (to me anyway, maybe it's common). After awhile driving, it starts pushing all the power steering fluid out of the pump reservoir fill hole. Appears as if it's boiling it, as it's very hot and frothy and literally boils out. The steering box is pretty worn, on the to do list is to adjust the screw on the top as it's pretty loose (I know its a band aid and I'll eventually replace it) and the valve at the top needs to be adjusted as it turns itself to the right. Is the pump shot or is it continually being worked by the out of adjustment steering chuck?

Adjust it so it centers itself and then see if you still have the same problem.

Yes it's being worked by the out of adjustment box.

Thx for the reply guys, I figured that had something to do with it. Any good info/links on how to properly adjust it?

if the reservoir is overfilled it will Puke when warm or hot as the fluid expands when Hot,

your pump might be bad. does the pump sound like it's whining? something in the pump might be causing the fluid to boil. harbor freight sells a laser thermometer that works great. get one and see how hot it's getting. this will give you an idea where the hottest part of the power steering system is. and go from there. how are the hoses? if the fluid is boiling, then they should be getting hot too. if not, it could just be in the pump. fix the other problems too. it might be a combo of everything.

Check for any blockages in the lines..

The Factory Service Manual has the procedure if you can get one (good idea anyhow, MoparManuals.com). Its been posted a few times but I've never done one. Basically you slightly loosen the block and tap it left/ right with wheels in the air and engine running until you find the point it stays centered and tighten it down.

A power steering cooler would help keep things cool and prevent boiling also... but need to get the box healthy first.

The pump doesn't whine when it's full and the cars cold. It's not a matter of it being overfilled I don't think, when it gets hot and starts boiling over it will boil over until it's empty and then it starts to whine. I'll check the line and see if they get hot as well, they appear in good shape and the steering effort is very easy

OK but with the assist valve out of adjustment, the pump is constantly trying to build pressure. Building pressure builds heat.

With the assist valve centered, the pump merely circutales fluid and stays cool.

I adjusted the centering valve on the steering box and its seemed to have fixed my boiling power steering pump. Guess it was continually working itself (wanted to turn itself to the right) and was heating up to much. Btw, the centering valve had to be tapped towards the rad cradle to stop it from turning itself to the right.