I have a daily driver 2000 Corvette with 145K miles. I have never had any problem whatsoever with the steering. The harmonic balancer was coming apart, and tossing out the rubber isolator ring. I pulled it apart by the book, replaced the balancer and front seal, idler pulleys, belts, and both tensioners, then reassembled by the book. I made sure that I kept the rack as level as possible, and only dumped about a tablespoon of oil out of it in the process. After reinstalling the rack and pinion, I filled the p/s reservoir with fresh p/s fluid, and tried to use the quickie method of bleeding by turning the wheel from side-to-side without the engine running and with the wheels off the ground. When I started it, I had no assist even with the wheels off the ground.

I then went to the factory manual method of pumping the reservoir into a vacuum, rechecking the level, pumping into a vacuum, etc, etc, etc. I still have no assist, unless the engine is revved up to about 2000 rpm, and sometimes it growls like it has air stuck in the system. I struggled with it all day Sunday to no avail. Monday came around, and I had to take it to work. It drives fine on the road, but really sucks in the parking lot. (I made it into a real muscle car...)

Question. What the heck happened? How can air get trapped in a system with the reservoir on top, pump in the middle, and rack on the bottom? Power steering fluid is heavier than air, and the air should naturally work it's way to the top, right??? What are the odds that the power steering pump decided to die just at that moment? Or is it the rack and pinion that died? I even tried pumping the reservoir into a vacuum while the engine was running hoping that it would circulate the fluid, and work the air out. No such luck.

Anybody else ever have this problem? Any help would be appreciated.

Thanks,
thundertruck

 

Did you follow the FSM guidance? It includes a vacuum drop test.

 

Here's what has always worked for me, start the engine turn the wheel all the way to one side turn off engine and go have a beer or anything else.
Return and check oil level in PS start engine and turn to the other stop and shut off, go have another beer return and start engine center wheel and shut off.
Again check oil level and top off, you may have to do this several times since you introduced air into the system by the way you attempted to bleed it the first time.

 

You did remember to hook up the magnasteer connector?

 

Yes I used the factory shop manual method with the vacuum drop test. It warns to not exceed 20"HG, so I kept it down to about 15-17. I also put new O-rings on the lines on the rack.

 

I found your post, and tried it to no avail. During the week that I drove it to work, I would park it with the wheels one way, then the other way when I got home, letting it sit that way for at least 8 hours each time.

 

Yes, even clipped the connector back onto the cooler line in the same place.

 

What was the vacuum drop? And over what time?

 

When I did the vacuum drop test, I did not actually time it. I put 17 inches of vacuum on it, then went about cleaning up tools and putting stuff away, etc. It was on for at least 5-10 minutes, and was still just above 15 when I returned, and the fluid level was unchanged.

Today I decided to redo the bleed procedure again, and actually time it. Checked the fluid level, and it was just below the full cold mark. (possibly some air worked it's way out???) Added fluid to the cold full mark and put the vacuum to it. At 17", I could feel air bubbling up inside the reservoir. (finally getting the air out right?) After 30 seconds of bubbling, I decided to check the fluid level again. (Don't want to run the reservoir empty now!) The level actually went up almost to the hot level. Apparently now it's pulling air into the system, causing the fluid to move up to the reservoir. Never did that before...

Thinking that if air could get pulled into the system, fluid under pressure might just leak out at the same point, I went hunting for leakage signs. I found a slight dampness at the rack steering shaft seal lip, and a small amount of wet fluid at the large adjustment nut on top of the rack. Looks as though the rack is now starting to leak. Is this because I have been driving it for a week without steering assist???? It sure puts a lot more mechanical strain on the input shaft of the rack assembly when there is no power assisting the movement of the rack. So, is it the pump that magically stopped pumping at low rpm which caused the new leakage? Or was it the rack all along, which magically stopped functioning because I removed and reinstalled it?

What about trying Lucas power steering sealer? I know GM does not recommend that, but desperate times... Besides, you cant kill a dead horse.

thundertruck

 

Has anyone ever done a reseal on their rack assembly? Is there a reseal kit available? I have seen them for the p/s pump. I know it is not a rebuild, but $430.00 for a crappy rebuilt unit is not something I am ready to go for. Then there is still the question of why the system quit working in the first place.

thundertruck

 

I have done over 12 cam swaps in C5s and never had a problem priming the power steering system. Sounds like your pump or steering rack died.

I just replaced my leaking steering rack (recently turned over 300k miles in my '99) with a rebuilt one for $210 plus shipping from Zip Corvette. I also replaced the steering pump with a rebuild one from Oreillys after the original one started leaking days after replacing the steering rack. Mine has been working well since.

 

I would start with another rack. I would make sure the pump does not have any debri in it. If that does not do it then replace the pump.

You can try the sealer. If it works it could at least prolong the ultimate fix.

 

Here's a dumb question. Is it possible to put the lines onto the rack in the wrong positions? I don't think that I did since they went on with no problem, and I'm pretty careful about things like that, but I am human, and subject to the occasional brain fart. I'm just trying to find a reason that a perfectly functioning system quit at the very moment the rack was removed and reinstalled. I can't seem to find a picture showing which line goes to where. I have the cooler line in the bottom hole, which is closest to the outside of the vehicle. Can anyone confirm the correct positions?
thanks,
thundertruck

 

Don't have my car at home to check it. From the FSM, I show the return line has the cooler in it. This line connects to tubing that is on the front side (between rack and bumper) of the rack. I assume the pressure line connects directly into the rack, not connecting to exterior tubing.

 

Perhaps you misunderstood my question. I know which line is the pressure line, and which line is the return line (the one that goes to the cooler). What I am trying to find out for sure is which line goes into the top hole on the rack, and which line goes into the bottom hole on the rack. I believe that I have them in the correct locations, but I want to eliminate that possibility as the cause for the lack of steering assist.

 

The fittings are different size

 

I knew what you needed, I could only provide the into from the FSM pictures. It would make sense that the pressure line would be at the top and return at the bottom.

 

You should get a cap for the return line port on the reservoir and then route the return line up to the cap opening. Start it and see if fluid is flowing. That would at least show that the pump is pumping. You could also probably partially pinch the line off and see if it starts to make pressure.

I had a LT1 pump that didn't make pressure but I didn't spend much time troubleshooting it because I had a spare so I just swapped it instead. I suspected the pressure valve was blocked/stuck though. They really aren't that complex so if dirt got into it and something is sticking or blocked it's not terribly difficult to pull it apart. You'd just need the tool to pull the pulley off.

 

Thank you to everyone who responded to my request for help. I appreciate you all taking time to help a total stranger.

It appears that I have had a bit of divine intervention. Friday night I parked the car with no steering assist, and planned to dig into it again on the weekend. Saturday morning I needed to run a couple errands before I tore it apart again. As soon as I started the car, the power steering worked perfectly. The only mechanical explanation I can come up with is that the pressure relief valve was stuck open for some unknown reason, and just became unstuck. Or did one of you guys come over and fix it while I was sleeping?

I still have the slight seepage at the rack adjustment nut, but for now at least, I will live with that. The Lucas stop leak might be in my future if it starts using fluid. At this point, I'm hesitant to mess with a functioning system. Don't know how much you like power steering until you don't have it for a couple weeks.

Thanks again,
thundertruck

 

Well, I guess you are "thunderstruck" for sure.