Power steering.....sometimes

damoroso

damoroso

Well-known member
Joined
Aug 7, 2008
Messages
409
Location
Middleburg, FL
I've been getting the odds and ends of my project sorted out and now that everything is running and working well, it's on the power steering. I think I know what's going on; I just don't know how to fix it. I adapted a serpentine set up to the front of my big block from a 91 S-10 V6 pick up and used all the pulleys that came with it. I rebuilt the original power steering pump from the car, using the original housing as well and installed the serpentine pulley I got with the set up on it.

Here's the issue. Sometimes the power steering works, some times not so much. Most of the time it's not working is at idle (like when parking) but always after higher RPMs, the steering is like a belt is off and you've got no hydraulic assist. If the car sits for a bit, or if you just cruise easy, the steering is fine. I know there are actually two control valves in the system. There's one in the pump, and the other, infamous power steering control valve on the linkage.

The only thing I changed on the steering is the pump pulley and the rebuild of the pump. My thought is the flow control valve inside the pump is causing this problem perhaps because the pulley is spinning the pump it at a different speed than the original v-belt pulley would :confused:?? I compared the flow control valve inside both the original pump and the one that came with the set up, and the original vale has the end screwed in all the way, the other one is out about ¼ inch. Is this the problem?

Any thoughts or suggestions are appreciated!!
 
Sounds to me like the pulley size is the culprit. Spinning to slow. Are they different diameters?
 
I put a 89 camaro serpentine drive on my 82 vette pretty much like what you used with no issues. Have you checked the tensioner to make sure the belt is in the proper wear range?
 
pump catch is what you are having, too little flow. Pulley too large.
 
Dave, here is a thought.....take your timing light and put aim it to the p/s pump pulley, rev the engine through any reasonable rpm range....wonder what you see, relative to say the crank pulley....

since they are nearly 1-1 typically.....

check the position of the belt tensioner, belt too long, ? not enough tension, and barely makes traction for most of it, but slips on the pump??

:gurney::drink:
 
Thanks for the comments guys, Gene, Jeff, the belt is good, it works the A/C compressor fine, I'd think that has more drag on it than the PSP.

Steve, TT this makes sense the serp pulley is a bit larger than the V belt pully, and explains why the flow control valve in the oringinal pump has a different setting from the original. I'd think with the adjustment on it out 1/4 it would take less pressure to start the flow from the pump.

I'll start with swapping the flow control valve, I don't have clue where to get a smaller pulley or how small to go. Any suggestions??
 
damoroso said:
I don't have clue where to get a smaller pulley or how small to go. Any suggestions??
Click to expand...

The mid 90's Grand Am uses a smaller pulley. About an inch smaller. The problem is that the offset is not the same. You would have to space the pump back about 1/2 inch to pull this off.
 
Thanks Larry,

I was just reading Jim Shea's papers on power steering, and I'm now thinking the problem really is the flow control valve/relief spring. I understand how the larger pulley could cause issue at idle, i.e. when parking, but how does that cause the problem at higer RPM? After running higher RPM, the steering is like the belt is off when your at slow speeds, like in a parking lot. It comes back after a bit, but still. In reading how the pump actually works, I think I'm going to try the flow control valve/spring before I look at how I'd have to change that pulley and move the pump. I have the spring and valve out of the "donor" pump, and my understanding is the donor pump used a bit higher pressure. Since the flow control valve is what controls the pressure, I'll swap those out first. Otherwise, you know the challanges there are in moving that pump!! :suicide:
 
I'm not at all familiar with the stock C3 linkage assist sytem but the design pressure was 960psi (IIRC). The new pump you have is probably 1300-1500psi. I can see where that might cause some problems with the stock system.
 
BBShark said:
I'm not at all familiar with the stock C3 linkage assist sytem but the design pressure was 960psi (IIRC). The new pump you have is probably 1300-1500psi. I can see where that might cause some problems with the stock system.
Click to expand...

Dave, the above is why I commented on the phone about my lucking out with using the lower pressure setup from my '72 in the serp pump....done for no other reason than wanting the flare fitting....had no clue about pressures/flows changing...never a second thought....

so I wonder if that flow valve needs BE the shark setup, and one way or another it has to be in there, or the pump goes into bypass?? maybe?? Jim Shea is the guy to know....

still wonder if maybe just maybe....the belt is one size too large and not enough tension.....screw that 240* wrap on the a/c comp...the belt on the typical p/s pump is much less....and without enough tension?? so see that you have about 1/2 the total available deflection of the tensioner pulley with the belt ON as opposed to off, as in relaxed.....:bonkers:
 
JeffP1167 said:
I should have mentioned I used my stock flow control valve from my 82 pump.
Click to expand...

Thanks Guys,

Gene, the belt tension is good, the tensioner is right where it's supposed to be. The only part in the system currently that isn't from the original power steering system is the pulley. That's why I'm stumped. I can see why the larger pulley would cause the pump to turn slower and would cause problems at an idle, but the high RPM's causing the thing to act like it doesn't have a belt on it, I don't get that. I can't believe I screwed it up so badly doing the rebuild, but hey, I've screwed up before!! I think the right thing to do here is to pull it off and apart and see what's not right. It was working fine before I "rebuilt" it! :cry:
 
damoroso said:
JeffP1167 said:
I should have mentioned I used my stock flow control valve from my 82 pump.
Click to expand...

Thanks Guys,

Gene, the belt tension is good, the tensioner is right where it's supposed to be. The only part in the system currently that isn't from the original power steering system is the pulley. That's why I'm stumped. I can see why the larger pulley would cause the pump to turn slower and would cause problems at an idle, but the high RPM's causing the thing to act like it doesn't have a belt on it, I don't get that. I can't believe I screwed it up so badly doing the rebuild, but hey, I've screwed up before!! I think the right thing to do here is to pull it off and apart and see what's not right. It was working fine before I "rebuilt" it! :cry:
Click to expand...

Wadda U? got a screw loose, ?? anyone knows if it ain't broke, don't FIX it....

jeez.....some guys are just hammerheads.....

:devil::friends::D
 
I think you still have a pulley issue. You mentioned that your steering is fine at highway speeds but when you come back down to slow speeds and parking you lack assist. One thing that could be happening is that your fluid gets hot at highway speeds and the fluid actually gets thinner with higher temperatures. When you return to slower speeds (with the hotter fluid) there is actually more leakage internal to the pump and valve because of the thinner fluid.

So the combination of a large pulley and thinner fluid causes the steering to feel like no assist.

Jim
 
JIML82 said:
I think you still have a pulley issue. You mentioned that your steering is fine at highway speeds but when you come back down to slow speeds and parking you lack assist. One thing that could be happening is that your fluid gets hot at highway speeds and the fluid actually gets thinner with higher temperatures. When you return to slower speeds (with the hotter fluid) there is actually more leakage internal to the pump and valve because of the thinner fluid.

So the combination of a large pulley and thinner fluid causes the steering to feel like no assist.

Jim
Click to expand...

Jim, could that same affect from hot fluid be the cause of a auto tranny shifting softer when hot as opposed to dead cold??

it's been my observation for decades that every one I have ever had did that.....gotta be something with fluid temp....:surrender:

but I would assume the thinner fluid would pump/pass through valving and hit clutches quicker.....which is obviously not happening, or the clutches are slipping??

any thoughts??...anyone??

:twitch:
 
damoroso said:
JeffP1167 said:
I should have mentioned I used my stock flow control valve from my 82 pump.
Click to expand...

Thanks Guys,

Gene, the belt tension is good, the tensioner is right where it's supposed to be. The only part in the system currently that isn't from the original power steering system is the pulley. That's why I'm stumped. I can see why the larger pulley would cause the pump to turn slower and would cause problems at an idle, but the high RPM's causing the thing to act like it doesn't have a belt on it, I don't get that. I can't believe I screwed it up so badly doing the rebuild, but hey, I've screwed up before!! I think the right thing to do here is to pull it off and apart and see what's not right. It was working fine before I "rebuilt" it! :cry:
Click to expand...

Hey I have an f-body pump for free. Never been rebuilt but probably work better. Seriously If you need one let me know, came from a 89 serpentine TPI car.
 
Jeff,

Thanks very much for your offer. I think I'm going to replace the current flow control valve and spring with the ones that came out of the donor pump. Those should be calibrated for the pulley size (and therefore the speed of the pump) that's on the pump in the car. I'll do that today or tomorrow. If that doesn't work, I'll be asking you what shipping is on the pump you have!
 
Well, changed the flow control valve yesterday and things seem much better. The steering is still a bit heavy at idle (I'm sure that's due to the pulley size) but it seems to be stable after hitting highway speeds and higher RPM. Thanks to everyone for their suggestions and input!!

Next is new bearings in the TA's....been chasing a noise back there and I think I found it.....The right side has a bit of movement in it, I'll have to put a dial indicator on it but I'm realatively sure it's gonna have to be done. And if you do one side....:(

The good news is once that and the front bushings and so forth are done, it's all new from the radiator to the tires!!!
 
damoroso said:
Well, changed the flow control valve yesterday and things seem much better. The steering is still a bit heavy at idle (I'm sure that's due to the pulley size) but it seems to be stable after hitting highway speeds and higher RPM. Thanks to everyone for their suggestions and input!!

Next is new bearings in the TA's....been chasing a noise back there and I think I found it.....The right side has a bit of movement in it, I'll have to put a dial indicator on it but I'm realatively sure it's gonna have to be done. And if you do one side....:(

The good news is once that and the front bushings and so forth are done, it's all new from the radiator to the tires!!!
Click to expand...

Yup, new China parts.....

just sayin'.......:devil:
 
mrvette said:
damoroso said:
Well, changed the flow control valve yesterday and things seem much better. The steering is still a bit heavy at idle (I'm sure that's due to the pulley size) but it seems to be stable after hitting highway speeds and higher RPM. Thanks to everyone for their suggestions and input!!

Next is new bearings in the TA's....been chasing a noise back there and I think I found it.....The right side has a bit of movement in it, I'll have to put a dial indicator on it but I'm realatively sure it's gonna have to be done. And if you do one side....:(

The good news is once that and the front bushings and so forth are done, it's all new from the radiator to the tires!!!
Click to expand...

Yup, new China parts.....

just sayin'.......:devil:
Click to expand...

No thanks, hey, didn't you get a free set of chop sticks with your last parts purchase??? :rofl:
 
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