Hello,

1975 C3: Swapped out the PS control valve (was leaking at adjuster) and it wound up overheating and blew the PS pump outlet line after 30 min drive. I have not been able to get my PS system working properly since. The valve was centered per the instructions.

I replaced the hoses and another new valve and still was over heating. I replaced the pump (it was leaking after overheating) and still overheats (>300°F tank wall temp using IR gun after 10 min drive). I replaced the cylinder and still overheating. Any ideas? Do I need a lower flow pump from a <1973 year?

Note: adjusting the valve was very "touchy" didn't have hardly any wiggle room between going in/out, only slight nudges were used to keep it centered. Maybe this is an indicator something is wrong with the valve or installation method? Both valves I received from CC were like this.

The valve: https://www.corvettecentral.com/c3-6...lve-new-562336
The hoses: https://www.corvettecentral.com/c3-6...h-clamp-562340
The cylinder: https://www.fullthrottlecorvette.com...er_p_3044.html
The pump: https://shop.advanceautoparts.com/p/cardone-power-steering-pump-20-6886/10393039-P

 

Can you post some photos? Could something else be going on under the hood that is causing those temperatures? Do you have a 5.3L LS with a turbo mounted right next to the pump, and no airflow, for example? Or a comically undersized steering pump pulley?

I can't explain your overheating, but I think @leigh1322 found a way to limit or regulate the pump pressure. I'll include a link if I can find it.

I converted both of my cars away from stock power steering, but used this pump with my Borgeson converted 79, which included the reservoir. I still had to swap the pulley, though.
https://www.rockauto.com/en/moreinfo...t=7380&jsn=910

 

Nothing special going on under hood. Stock 350 block w/top end kit. I am using factory size pulley that was on the original pump that was not over heating originally.

That is the exact pump I'm using.

 

Just looking at this from the outside. It's been working fine for 47 years and you change something and all heck breaks loose. I would tend to say that you didn't do something right.

I just rebuild my power steering control valve because it was leaking. The adjuster nut on the end actually took multi turns when reassembling with the front tires off the ground to keep it from turning the wheels to the left. I just ran it in until the wheels stayed stationary. I had the whole thing apart in a pile of pieces and a little phony diagram of what it looked like all stacked together on the central adjusting rod.

Is it possible that you have the pressure and return to the opposite spot? Or with the tires off the ground , engine off, can you grab the tire and manually move it lock to lock without binding. Or sitting in the driver seat, engine off, turn it lock to lock without great effort? If something is bound up, you will overheat the pump.

 

They cannot be backwards as the fittings are different sizes into the valve.

I wonder what kind of mistakes could be made with valve installation? The hoses are correct, everything else went by the books. The only thing that was off to me was that the adjustment between the cylinder going in/out was fractions of a turn. This occurred with the first and second valve I got from CC.

 

Might your drive belt be too tight? Or maybe the pump's bearing is beginning to seize and causing the heat? Other wise, the rest of the system has extremely little friction or close proximity to heat sources and it's hanging out with full air flow all around.

 

gkull brings up a good point. When new replacement parts fail that soon look outside the box.

There are several places that could be taxing not only the C.V. but the pump too. If the system is binding those two can not overcome binding issues.
The outer / inner tie rods could be binding, pitman arm, four ball joints and maybe even an idler arm that hasn't been greased in 40 yrs.
As mentioned, test the steering components to see how much labor is involved to move the front tires lock to lock.

 

I think he means the ram lines could be backwards. They have to crisscross.

 

The castle nut does Not suck up the tapered shaft. I use a big C Clamp to press them tight first and then run down the castle nut and cotter pin. End joints spin, so you have to seat them first to ensure that you are not changing the rod angles.

Something has to be binding to over work the pump. You have to position the hard line hoses tightening down the flare fittings before, so they are not dragging during steering arms travel. It all changes also from wheels off the ground to compressed with weight

 

I'd be willing to bet the pump is running hot because its working to hard. As in the pressure is high because the Oil doesn't have anywhere to go. Something up stream is blocking the flow. And since You just replaced the Valve that controls the flow of Oil its easy to point at it. Do You still have the old one for a drive around the block ?

 

Clog in the line? Bent, twisted..the high pressure side? Orifice clogged?
pic?

 

Check the return line in ALL steering positions. sometimes this is overlooked. Straight ahead all may be good. But at right lock or left lock return line could get crimped shut by the movement of the draglink.

 

I will check for this. I know the cylinder lines to valve have clearance lock to lock, never checked the return line.

I do still have the original valve, I loath putting it back on, what a mess!

 

Were all the parts specific for your model of Vette? Corvette PS pumps run a different line pressure than other Chevy's

 

Look at first post

 

Does the new Pump have the same diameter Pully as the last one ? I'm a bit concerned that the Autozone Pump is a one size fits all GM.

 

They come WO a pulley. You have to swap yours on. IMO even is you spin the pump faster it's not a big deal. I have run my motor over 6000 rpm for long periods of time and never had PS problems

 

The return hose was dressed properly to not kink when I started looking at it today. I checked the fluid, hoses, and valve install again, no issues found. Started it up in the air and seemed like it was ok. Dropped in on the ground to see how it felt with some resistance. The system had very little performance near idle (was not providing assist)

To make my day it popped the brand new (from CC) return hose somehow at the fitting between rubber/metal at the exit of the valve. How did it pop there and not the fittings you could remove with you hand I will not understand. Also caught fire when it dumped the power steering reservoir content on the header, hurrray! It was quickly put out. No harm done.

No debris was found in the filter you see in the photo. You can easily blow through it w/o any restrictions. To me something had to be backing up in the pump return??? I have no idea, this is the dumbest, easiest thing I thought to simply repair and I am failing. I am not an idiot, I work on my GenV V8 car all the time w/o issue and this is WAY easier mechanically.

I think my path forward is go with a <1973 pump with lower flow and a new return nose and see how that pans out... I have already swapped in a replacement valve so two in a row creating the same issue doesn't seem likely. The hoses should not be a contributor. The cylinder I cannot see having any impact here.

 

I actually have a 8 X 11 auto tranny cooler on the return line to the pump res. RPM and big front tires would ruin the pump to res O-ring and it would start leaking

 

Hello, I just came across your post about power steering overheat. I have had the same problem. My Control Valve was leaking leaving a small puddle. I purchased a New Valve, installed it , bled system as per directions. Ran car on lift for awhile and topped off fluid. All seemed good. Took car out 10 miles run and P/S pump overheated and was damaged. I have never had this fialure and am at a loss. What was the outcome of your parts failure? What was the solution? Thank you in advance for any suggestions.