tim_briz

Just wondered if anyone had any insight into my newest problem. The return line keeps blowing off the back of my power steering pump. This should be a low pressure line, but even with two hose clamps on the rubber line it will sometimes blow off the pump and empty all the fluid. It has happend three times and I have put two new hoses on it but no luck. It seems to happen when you turn the wheels all the way in one direction. Like when it turns all the way a back pressure is sent back through the system and blows the line off. All the componets are new or rebuilt, but that dosen't really mean anything. Any ideas or insight would be helpful. I checked the archives and didn't see anything so I assume it is a weird problem.

Tim

Jim Shea

For the most part, I think that the hose would rupture and leak before it would actually blow off of the pipe on the pump if somehow there were excessive pressures. It must be something else.

Do you have the production return pipe at the valve? Is it oriented so that the short straight length angles slightly forward when the pipe is tightened on the valve? Are you using the right length rubber hose? It should be roughly 14.5 inches long. Are you using the production pump reservoir? The return hose tube on the reservoir should be pointing down.

If you have an AIM book it has a description (not really clear however) of the hose routing and how the pipe(s) are to be angled on the valve. If you need one, I can scan it and have Terry Rudy post it at http://www.corvettefaq.com in the Steering section.




[Modified by Jim Shea, 11:41 AM 10/20/2003]

tim_briz

I do not have the production return pip on there I made one to match the original after the first one blew off. It may not be accurate though. The hose length was also matched to the orginal. I would have to measure to get the exact length but I believe it to be close. The pump is correct and pointing downward. I have an AIM and will compare the setup to what I have. I am not sure that a change in angle of the return pipe is going to keep it from back flowing. I like you would think that hose would burst before it comes off but apparently the connection is weaker than the burst strength of the hose.

Is there something inside the valve that could be causing the back flow when the cylinder is at full extension? Is there a pressure relief valve that is not working? I am not very familiar with the internal workings of the system so any comments are appreciated. Maybe if I bought another factory hose it would fix the problem but I am skeptical?

Tim

Jim Shea

The fluid is dumping directly back into the pump where it connects to the spout that is brazed on the back of the reservoir. The is virtually no way that you can create pressure in the return hose at that point.

This assumes that your system has worked correctly in the past.

For example, when the pump and reservoir were manufactured almost 30 years ago, it was rare but I had heard that brazing material could block the entry where the steel spout joined the back of the reservoir. If this was the case, you would have been having 30 years worth of problems, pumps making noise, pumps failing to flow oil, hoses rupturing, hoses blowing off, power steering oil black and smelling burnt, etc.

Put your front end up on jack stands. Have someone turn the steering wheel lock to lock. No need to turn the engine on. Look closely at your pressure and return line hoses as the linkage moves from side to side. Is there any position where the hose(s) seem to stretch? They should have a generous arc from the valve to the back of the pump. They should not be stressed by the motion of your valve and linkage.

Sandeep_19

Sorry to bring back an old thread but did you figure out why the return line keeps blowing off? I am having the same problem

Jim Shea

You will note that in the PM to you, I added the comment on the location of the magnet inside the pump. Make sure that the magnet is not somehow trapped between the reservoir spout and the pump housing. Not that the drawing says that Magnet (Z) should be located at about the 4 o'clock position just above the stud inside the reservoir. That is the only additional thing that I have to offer.

Jim