After steering failure it keeps a grinding feeling when turning?

[Peer81]

Hello everbody,

Today a great day overhere, the first parking lot trackday!
So in short, started the track without any problems most in 1st and sometimes 2nd gear. I think somewhere at 3/4 of the track there was a 180 degrees turn. Well, my turn stopped at 360 but that is were the fun is. After that I feld my p/s steering was gone but with "manual" steering I finished the track. Checking the fluid it was at the bottom of the stick (a few mm under the add point). Added about 1 theacup with fluid (to get it past full) and drove some tight turns to get all the air out. Most of the power steering assistance came back but also has a grinding feeling in the steeringwheel when turning the wheel.

I didn't continue the trackday and at the end of the day I drove home. At home got the front of the vette up in the air. Got the lid off the steeringpump, started the car and starting steering from all the way left to all the way right and back, did that for 5 to 6 time and all seemed to be nice again. When going from left to right almost at the limits the steeringpump seems to make a light short peeping noice but its just short.

Lowered the car and took her for a spin. Powersteering is all the way back but the grinding feeling is still in the steeringwheel when I turn into a corner. So what could this be. I already checked the shopmanual but I can't find the same problem symptoms.

Btw. No leaking from the system (also don't know why there was not enough fluid in the pump. Pump is a new or rebuild one from Rock, installed I think 6 months ago. The belt tension is good, powervalve was rebuild a long time ago but is centered nicely also no leaking. Power cylinder is new and hoses are new. Steering house rebuild by me and adjusted with proper dial torque wrench.

I'm thinking the pump is the problem and needs a rebuild but maybe I'm thinking into the wrong direction?
Thank you,

Greetings Peter

 

[Hib Halverson]

Do you feel/hear this grinding when turning the steering wheel back and forth when the car is not moving.

When you feel/hear it as the car turns, to you feel it during turns in either direction or just one direction?

 

[Peer81]

When I tried turning the wheels when standing still on the parking lot that wasn't possible. But at that moment powersteering was somewhere in between manual to p/s. As I never turn the wheels when standing still I didn't try it when I was at home.

I could hear some kind of rattle comming from the driversside enginebay, almost like something has come loose but I couldn't find it with a hot engine and inside there wasn't enough light. When driving I feel it in both directions, it's not something that is overwhelming but it's there "midway" or in the background. I also hear something comming from the enginebay sounds like a rattle with sometimes the sound of a loose bearing.

As I the wheelbearings don't have 2000 miles on them and I set them to the better then factory spec's I don't think there are the problem for the sometimes squeeking sound.

Greetings Peter

 

[Hib Halverson]

Is the power steering hardware original? If so, how many miles are on the car?

 

[Peer81]

Ow yes I forgot, everything is still original!
Vette has been body off restored from 2003/2004 till about 1 year ago. From then till now it has driven about (max) 1500 miles. Steeringpump has about 500 miles on it and the powervalve has been rebuild before the body off (9 years ago) and has max 2500 miles on it.

Greetings Peter

 

[Peer81]

Anybody?

Greetings Peter

 

[Vettehead Mikey]

For clarity, is the grinding noise constant while the car is in a turn, or only when the steering wheel is being turned at the beginning and end of a turn? Just for a test, remove the drive belt and go for a drive to see if the grinding is still there.

 

[Peer81]

I think I found the problem. As I still have my old steeringpump laying around I remove the new one. It's turning very heavy, the steeringpulley wasn't exactly solidly locked around the pumpshaft to begin with but now I could remove the pulley by hand and it even has space between the pulley and the shaft! :ugh So for a while the pump was turning slower then the pulley was...

I'm going to buy a rebuild set for the pump and a new pulley. I'll let you know when I'm ready. It's only ashame its happening right when the temp is in the mid 80's overhere!

Greetings Peter

 

[Hib Halverson]

Sounds like the pump failed.

Know that when that happens there is often metal debris in the hydraulic ram, in the control valve and in the hoses. You're going to need to flush all the parts to get all that crap out of the system otherwise you'll damage the rest of the parts in the system and any new pump you install.

 

[Peer81]

Can I flush it with compressed air (not to high psi) or do I need to flush it with oil? I know (or think) there is a filter inside the pump but is there also a filter somewhere in the other parts so I need to open it somewhere else?
Thanks!

Greetings Peter

 

[Peer81]

Flushed the system both ways with compressed air. Wasn't that much oil in it any way. Put the new pulley on my old (still good) pump. Connected everything, started bleeding the system by the book, no problems there. Can also turn the weels from side to side (with wheels on the ground) without any problem, only hear the steering work but I think that is normal as I normally never turn the wheels when standing still.
Need to check for leaks and the oil level today and then she is ready to go again

Greetings Peter

 

[Peer81]

Well it looks like the devil is sitting next to me!
I put back on the old ps pump with the new correct pulley. I rebuild that pump about 5 years about but drove only one year with it because I was loosing ps steering support at low rpm's.
So took all the air out of the system like the manual said. As we don't have GM ps fluid overhere in Holland we put in automatic transmission fluid. Filled to the right level and ready to go.
After a 30 minute drive (temp in the 80's) I had to overtake some trucks, on the gas rpm to about 3000 or a little more, after that a sharp turn, low rpm and the steering assistance is gone! When getting the rpm up over 1000 I could feel the ps steering comming back. No problem except in the towns most corners are low rpm to alot of muscle work to do. After about 20 minutes driving with this in a low rpm sharp turn half way ps steering is fully back without a worning!? After 10 minutes we got to some friend of mine. Showed the car took the kids for a quick drive, some sprints getting up to 4500 rpm without a problem. In the evening getting home after 10 minutes I could feel at low rpms the power steering failing again. Drove her home that way and can't say the power steering came back.

Tomorrow I will recheck if all the air is out of the system and see if I can turn the wheels at higher rpm when standing still.

The only thing I can come up with is that the ATF fluid is more sticky then the GM PS fluid. That way at low rpm the little metal vanes will not come out compleetly so the pump is not building up enough pressure. Could this be the problem?

Of course I have done a quick google search and found some other C3 owners with the same problem normally fixed by changing the ps pump. I did that to till the new pump failed.

Greetings Peter

 

[Peer81]

Check for air in the system, none.
Started the vette with PS. After some driving PS was gone (for sure in low rpm, don't know for higher rpm) and at the end of the 30 minute drive PS was fully back.
Who has an idea?

Greetings Peter

 

[jw15870]

Hey there, two guesses:

1) Your belt isn't tight enough and the pulley stops spinning at low rpm.
2) I have just rebuilt my engine and have a new PS system. I am still working through timing issues, etc., but once I get the engine running, my next task is to balance the PS cylinder. The instructions that came with the new system state that this is important in order for the system to work properly. Last week, I had the car out of the garage and got the engine running. It started to rain, and even though the PS cylinder has not been balanced yet, I decided to turn the car around in the driveway and drive it into the garage. Long story longer, the PS system groaned and creaked and all I had was manual steering. It sounds like you may getting the same response. Since you flushed your PS cylinder, you may need to rebalance it.


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[Vettehead Mikey]

Peter-

There is a pressure relief valve somewhere in the system, I forget exactly where. Sounds like yours is intermittently sticking open.

 

[Peer81]

Thanks!

I checked the belt today and I think it is within spec, there is more play in the belt then I want so I'll tighten it a bit. But I think if the belt is slipping on the pulley I would hear it scream.
As the system failure is both ways (left and right) and when the system is working I don't have any problem with the PS balance I don't think that would be the problem.
Somebody else also pointed me to the pressure relief valve so that could be the problem. I'll look it up and check it out on the broken pump so I can see how it works

Greetings Peter