Hello, I have a 67 coupe with a 302. The front end was rebuilt and all the power steering components were replaced a couple of years ago. Recently it has developed a loud "POP" when the car heats up as you turn the steering wheel right and left from center. This can be heard and felt through the steering wheel and floorboards. When the car is cold this does not happen. The warmer the engine gets the louder the noise gets and it actually starts to stick so that you have to jerk the steering wheel to break it free. The car has headers and has the extended bracket so the power cylinder will clear the headers.
I thought the headers were causing the power steering fluid to heat up so I wrapped the headers in heat wrap but it did not fix the problem. I had a mechanic give it an alignment and look at the power steering system. He found nothing was loose but had no suggestions as to the cause.
Any help or suggestions would be greatly appreciated.

 

Did you weld the extension bracket to the frame??

If not, this might be moving. If it isn't, it will, tearing the crush nuts out of the frame sooner or later.

Dan @ Chockostang

 

Yes, the bracket is welded to the frame because the bolts did previously rip holes through the frame. I have checked the brackets and made sure everything is tight. Since it only happens when the engine warms up I think it is somehow related to temperature. Possible the power cylinder is bad, I just don't know.
Thank you for your suggestion Dan.

 

If it's that loud and obvious I'd do it at idle at your house. Put a couple of poly floor tiles together with some grease between them and put them under the front wheels so they can turn with no scrub resistance. Have someone turn the wheel while you look. Make sure you have in park, emergency brake on, chocks under rear wheels, etc. You may be able to isolate by view or feel through fenders, frame, etc.
Watch the pitman to control valve ball stud closely, valve may be sticking?
http://www.stangerssite.com/HowItWorksControlValve.html
http://www.stangerssite.com/KnowControlValve.html

I am thinking of putting a PS cooler like the boss's and BB cars had just to make sure I have extra cooling if I do an opentrack event.
Jon

 

Thank you Jon,
I took your advice and got under the car when it was cold and then again after it warmed up. There was no noise when it was cold but a loud pop and vibration in the power cylinder when it was hot. There was nothing loose but you could feel and hear the pop in the power cyinder even before the front wheels started to turn so I'm thinking the cylider must be bad. I still wonder why it only happens when it is hot??
I appreciate the suggestion, hopefully we have narrowed the problem down.

 

When you say 'cold' do you mean not running or running and just not up to temp. yet?
If it was running but not up to temp yet I'm not sure why it wouldn't pop when cold but would when hot. Hopefully one of the PS guru's can advise. Did you notice any difference in the movement of the ball stud on the control valve?

Have you greased the nipple on the control valve? I read this on Stanger's site:
One mistake that is often made by people installing new or rebuilt units is the tendancy to over-lubricate the ball stud area. Many people will hook up a grease gun to the fitting and pump away until grease starts blowing out around the ball stud. The problem with this is that it is possible to over-fill the ball stud area and impair the operation of the unit. If too much grease is pumped into the ball stud area, it can fill the unit to such an extent that the pieces inside cannot slide and move properly. It is possible to form a "hydraulic lock" inside the ball stud sleeve because there is no room for the parts to move inside because of the excess grease. When this happens the ball stud will not move like it should and actuate the control valve. Usually this causes the steering not to provide power assist when turning in one direction. Over filling the ball stud area is not a warranty problem and easily identified. Go easy on the grease - a little bit goes a long way.
Jon