I was working on my ‘71 and pushed it around without it running and steered if left and right. After completing the work and starting the car the power steering return line was leaking. I tightened the clamp and it then blew the line off. The line wasn’t flared so I flared it and made sure the clamp was past the flare and tightened again. After starting the car and revving the engine slightly it blew off again. Could I have done something to the system by steering without it running, I never had an issue with other cars. How much pressure is in the return line?

 

Over filled resivor? Blocked inlet fitting?
I'm really not certain without being there.
I can say I've blown a few return lines over the years. But because they move and flex so much.
Moving the car around not running did not affect it. That much I'm certain of.

 

Maybe an old mushy hose? I've gone away from the old worm gear hose clamps. I gone to the fuel injection style hose clamps. I think they clamp better and and look better. Just my .02.

 

I removed the original Factory Power Steering system and switched it over to a Power Rack and Pinion which has worked great for me. Now I am eyeballing the "electric" power steering systems like modern cars use. It would be "fairly easy" to swap one in to the C3 and I would love to get rid of the extra weight from the hydraulic system.

Turn One is the place to go when you have questions or problems. If it has to do with steering then they are the experts.

 

I blew through the hose and it was unrestricted to the reservoir. trimmed the end of the hose and used two clamps. Filled the reservoir to the right level. Started the car and started to drive. I noticed a slight pull to the left and what I would call a straining pump sound. Didn’t get more than a hundred yards and the pull and straining sound stopped along with a puff of smoke and a trail of fluid. This time it blew off of the reservoir. Everything worked fine prior to steering the car when not running. The replacement fluid is clear an GM approved and the original fluid was red, assuming ATF.

 

I am thinking your control valve is off a little. It possibly needs to be adjusted or just overhauled.

 

OK, your looking for help. So I will try.
first off you keep saying that somehow turning the steering wheel without the car running must somehow be the start of this.
I'm saying that this is just a coincidence.
We all turn our steering wheels without the engine running. This can not be the cause of your trouble. Just a mere coincidence.
In our C3's we do not have power steering. We have power assisted steering. The difference here is that if you look, you will see you have a manual steering gearbox. The power ram is attached to the frame and the draglink. The control valve is mounted on the end of the draglink to the pitman arm.
it's a very simple system in theory.
How it works.
When going straight, the control valve is centered. All the fluid from the pump is just heading right back to the pump resivor via the return line. No fluid is heading to the ram. (If everything is adjusted correctly).
When turning left or right the control valve sends fluid down one of the lines to the ram and allows the other side of the ram to release pressure.
So, unhook the ram from the frame bracket. With all lines correctly hooked up. And the resivor about a third full. Push the rod of the ram all the way inward. You do NOT want to have the car running. As you push the ram inward you should hear bubbles in the reservoir as you push out the air. Now, slowly pull the ram outward untill it hits its internal stop. Also while pulling the ram you should hear bubbles in the reservoir.
Now check the fluid level. It should have gone down as you pushed out the air. Top up and repeat the push pull of the ram. Listening for bubbles. Usually 3 times of this will work out all the air.
If you never hear bubbles and your not getting the air out something is wrong.
Once all the air is out. With steering wheel straight ahead. Start engine. The rod on the ram should not move. With the engine running you should be able to slowly push the rod in and pull it out. If it slams all the way in or out all by itself. The control valve is out of adjustment. Remove the cap and adjust the control valve to get a neutral rod.

 

The return line that you have blowing off should be low-pressure (thus the hose clamp instead of the flared fitting like all of the other hose connections). If the hose end is not mushy, then it's a component feeding that line that is not correct. 4-Vettes has good advice to check the neutrality of the adjustment — if your alignment is good, the leftward pulling could indicate it's not centered. I'm not sure this is the cause of the high pressure return, but at least you could check that.

What diameter pulley is on your pump and what belt configuration is driving it? (A pic may help here).

 

I tried 4vettes suggestion and filled reservoir 1/3 full and disconnected assist cylinder from A mount. I bled cylinder cycling in and out until no bubbles heard and keeping reservoir at a 1/3. Started car and the cylinder did extend. Adjusted nut until finding a neutral setting. I could manually push rod in and out although with a lot of resistance. I noticed the lines getting very warm, car hadn’t been running five minutes and then the line blew off the pump again. Getting really tired of the mess this creates. I’ve only had the car a few weeks but have driven it about three hundred miles prior to this and the steering was fine no pull or pump straining noise. Surprised the control valve needed adjusting because it tracked true. Not knowing the valving of the control valve I don’t know if an internal failure is causing the high pressure in the return line or some kind of pump failure is causing internal pressure to blow return line. It seems to me that even if high pressure was being diverted to return line it should have almost no resistance dumping back to the reservoir. It almost has to be pressure building in the reservoir. Thoughts? Someone suggested posting a picture of pump and pulley arrangement.

 

Sounds like you may have to pull the pump at this point.
Check this old thread...
https://www.corvetteforum.com/forums...blows-off.html

 

That looks right as far as pulley and belts. If the inlet to the reservoir is restricted then the return fluid will build pressure at the hose - I believe 4-vettes first mentioned the inlet fitting. Can you easily blow air into the reservoir through the tube?

In your 2nd post you commented that there was a slight pull to the left.

 

This is definitely a strange one. When going straight ahead the fluid should just be cycling in a circle. Not going into the ram. Why it isn't just dumping into the resivor is strange.
I have blown a couple power steering return lines over the years, but they flex a lot from lock to lock. They just don't last forever. But this issue is ridiculous.
something is kinked, blocked or restricted somehow.
Never seen this.
I run a Tuff Stuff brand pump on my car. Works great.

 

You can convert to stock-style manual steering or Borgeson, though you'll need to get your power steering pump squared away in the later case.

I've done one of each. Ask, and I can post links/instructions.

 

Yes bench testing might be in order at this point.
The return line fitting is only a connection to the reservoir there should be no pressure there ever. Weird.
You can test it with an air hose to see if it is open or blocked.
You can bench test the output hose. Hold the output hose at the reservoir opening and spin the pulley, There will be no pressure if there is no restriction. The faster you spin the pulley the more flow should come out.
Most importantly there should be no flow inside the reservoir or bubbling, etc. from an internal pump leak.


But before you go down that road, let's keep it simple:
Did you change any parts on this system lately?
Or did the leak just start "by itself"?

If no other parts have been changed lately, it could just be the hose got too hard. Try a new & more flexible one.

 

Since the thread is getting lengthy I’ll recap what happened. I’ve had the car a few weeks and other than chasing down some vacuum issues the car ran really well. Steering tracked true with no issues. I was working on the interior and had the steering column lowered to remove dash. I needed to reposition the car so I pushed and steered manually. Once the work was complete I started the car and noticed the return line leaking. I tightened the clamp and started again and it blew off. I put a flare on the steel line and used two clamps and it blew off at the reservoir this time. Before it blew off I was able to drive the car about a hundred yards and it was now pulling left and the pump seemed to be straining until it blew off again. While trying to calibrate the control valve it blew off the reservoir again. It’s coming off with some real force/pressure. After the second blow off I blew through the return line. It took some effort but I attributed that to blowing the fluid through the line. While calibrating the control valve and bleeding the power cylinder I could hear the air gurgling in the reservoir so I don’t think the return port is obstructed. The return line seems relatively new, not hard or mushy. No recent work done on the steering system. I have the pump off and the pulley rotates freely. I haven’t tried spinning it with speed or blown air through it yet. I have another one on order.

 

Not that I can imagine this being related to your problem, but did you loosen the firewall connection when you lowered the steering column? If not, that's a great way to deform your lower steering column bushing.

Perhaps no one asked. Do you have stock steering components? Can you post pictures?

 

As far as I know everything is stock

 

What a clean looking car!

You didn't buy that from a man named Alan, did you?

 

Hank in Phoenix

 

I installed a new power steering pump, calibrated the control valve and drove the car for about fifteen minutes (didn’t want to get too far from home) and everything is back to normal. Old pump gave no indication of impending failure and I had my doubts that a new pump would resolve this. Thanks for all the input and help, I’ll update if something changes.