71 Skylark 455. Upon pulling my motor for a new rear seal and fresh paint and headers, I decided to replace that leaky power steering pump. I bought a Cardone remaned unit. Fully bled air out with fluid flush. Works great except when at idle in gear about 650 rpm it cuts in and out of power assist while you turn the wheel lock to lock. If you give it a little bit of rpm works fine. Thinking I got a bad Cardone pump, I just bought a ATSCO pump. Installed it tonight, bled it and added a new belt and tightened to proper pressure. Does the exact same thing. Stumped. My gear box is a remaned ATSCO unit, been on the car for about a year. What are the odds of two different brand pumps having the same symptom? Where should I be looking? Did not do this before I pulled the motor in November. Any ideas? Possible still air trapped? Or would that affect the power assist at all rpm?
Doubtful 2 pumps are bad, but I suppose weirder things have happened! You should kack the whole front of the car up so both frt wheels are off the ground. Turn lock to lock (not holding the wheel locked) many times. If you have someone to look...take off the pump cap + look. You can look yourself and see if there are any bubbles. It takes a while to get the air out. It takes a REAL long time if the wheels are touching the ground.
Thanks guys, I have done the lock to lock with wheels off the ground, 1st engine off then running. But yes, I can try again. The pressure and return line are both brand new. No funny whining just when at lower idle
I'm thinking of the pressure valve in the back of the pump. Is there a chance they still have your trade in pump? Where you could exchange the valve where the pressure line goes in, The big nut at the back of the pump? You didn't put a bigger oil pan on it that might be in the way of the drag link.
The original pump long gone as a core, but good thinking atleast. Same oil pan. Anywhere I you can just buy the valves? I hate to pull all apart again
I have a similar problem with my 83 dually. The steering is too easy and front end guys says it's the valve in the pump. So I haven't bought a new pump yet cause it don't leak. I looked online and some say they are the right ones but unless you have the correct GM part number you have to take a chance. If you call the restoration parts places than you can tell them your problem and see if they have encountered that request. That's what I would do unless someone else pipes in and tells you what is causing the problem. If it is the remann pump then you need to contact the people that are remanning the pumps and tell them your problem and what it took to fix it because your Buick friends are going to have the same problem and you will be the hero for fixing the problem with the other guys.
Here's an article that helped me out. When I got a new GN gear box, mine was pretty stiff so I used this page and a few others to find out I could take the shim out to increase the pressure. If you need a little more pressure at idle, you might get by with just removing a shim if it has one. It took longer to take the pump off and drain the reservoir than to actually make this change. See if any of the solutions for your issue are here: http://www.customclassictrucks.com/...rfect_power_steering/fluid_contamination.html
Great article Greg, possible might be the answer I needed to fix this issue. Possible I should check the pressure first and see how much is actually being produced. Navigating that article bit difficult. Where exactly are these "shims" located within the pump?
Try this picture: http://www.customclassictrucks.com/techarticles/1209cct_perfect_power_steering/photo_13.html The shim is the thing between the ball bearing and the plug on the right. This is where it came from, the outlet for the pressure: http://www.customclassictrucks.com/techarticles/1209cct_perfect_power_steering/photo_11.html
Thanks again Greg, Appreciate the pics. I will investigate. Again, just a PIA to deal with it full of fluid. Maybe I will pull a shim like you said if there are any. What would be the risk of too much pressure? Actually, for the hell of it, I still have the Cardone one which is the one that I just replaced on the bench. This is a new one too, the one that had the same symptom causing me to them purchase the current one. Anyhow, that one is empty on the bench. I will pull that one and look for the shim situation
Yes, if you have a spare sitting around, look at it for educational purposes. The following link shows going from 1 to no shim is good for 150PSI. I don't think an additional 150 PSI will hurt as that's about a 12% increase. Regardless, if you have one or more shims, removing one should boost pressure and allow you to diagnose if it is pressure related. Adding 100-150 PSI should make the problem better if it is low pressure related. http://www.customclassictrucks.com/techarticles/1209cct_perfect_power_steering/photo_07.html
Well thanks again for the nice detailed pics. I finally got a chance to pull the valve out of the Cardone that I swapped last week. This one is basically a new reman. Anyhow, no shims, none. So I guess it is set for highest pressure, so I assume the current one on the car is the same way since they act the same. So, I need to look elsewhere for the problem. Hmm.............If nothing else, this Skylark is never short of challenges
Now wait, now at further inspection, although there are no shims where the picture you posted shows one, the end that threads into the valve was not threaded in all the way almost acting as a shim itself. Hmm.... I was able to tighten it up all the way against the valve. There was a slight gap prior. I wonder if this alone would boost the pressure. Damn! Now my curiosity is gonna have me once again drain the pump and check the one inside. Damn! something had me looking again the gap was as if a shim was there, just none to be seen. Am I thinking about this correctly? Tightened further put more tension on the spring inside. This is gonna be a mess. Wonder if remanufacturer company does this rather than shim
I am now just plain perplexed. Being almost 50 degrees today, I decided to warm up the car and retest after I tightened the pressure relief valve nut all the way in. There is definitely no air bubbles left. At idle power steering feels good all the way left and right. But in gear break on.......at 625 rpm it is hard to turn lock to lock. Like it goes in a out of power assist. Why? Something else must be going on here
So, did tightening it change anything? If so, it may be pressure related but not enough pressure. Maybe the gear box requires more. I think they can be altered but I don't think it is for the feint of heart.
Tightening did not change a thing. I was thinking of maybe belt slip. When I reinstalled the motor month ago I resprayed all the pulleys. Maybe the belt slips because it has been painted? The pressure valve has zero shims and tightened all the way. The stupid thing was perfect before I pulled the motor. I wish I just kept the old pump and re-sealed it. If not the pulleys then maybe suspension issue. Again, was fine prior. Guess I could just increase the idle speed in gear, but I'll miss that cam chop
