No Power Assist on Steering

Tim_D

Active Member
Yeah, I saw those two instructional links as well. I performed the "stuck pressure valve" procedure on the first pump, but then I had the same symptoms on the second pump as well.

The Lares part number is 2309, which lists applications only for '86-'87 TR and '89 TTA, so the part number is right. It would be a major coincidence if two pumps, bought 8 weeks apart, were both mis-boxed as CCW rotation.

To me, the symptoms of zero power assist and no obvious flow (as observed in the reservoir) point towards either pump rotation wrong, a stuck pressure valve, air pocket, or blockage... But like I said, I've checked all those items at some point during troubleshooting. That's why I'm extremely frustrated. This is a simple system that I can't get to work!

I guess I have to start over with the stuck pressure valve procedure (AGAIN), bleed the system (AGAIN), and see where I'm at. Time to make another gigantic mess (AGAIN).
 

No disintegrations

Well-Known Member
Since the pulley runs opposite crankshaft rotation that makes it turn counter clockwise when running. (Viewed from front bumper) So, when the belt is off with pressure hose off, do you get oil flow manually turning pulley? Sorry if you know this but just to make sure. (There can be a ton of them boxed wrong, still looking that way to me.)
 

Tim_D

Active Member
Speaking with Lares directly, they are convinced that the pressure valve is stuck again due to incomplete bleeding prior to firing up the engine. They said that they field similar calls often.

The air bleeding, according to Lares, is very touchy and must involve:

1. Complete air removal prior to starting the engine. As it was described to me, the pressure valve clearance is very tight (0.005”), and can easily get stuck if the full whoosh of fluid hits prior to air evacuation.
2. The bleeding has to happen with the pump turning at or near starting speed. The procedure calls for disabling the ignition and using the starter motor to turn the pump. Too fast, and the check valve will get stuck. Too slow, and the bleed will be incomplete.
3. You have to do this VERY slowly. You start by only turning the wheel 1/2” or so side-to-side while the starter is cranking the pump, for about 10-15 seconds. After a short rest, perform the same operation again, increasing the wheel turning by another 1/2” or so.
4. Repeat this until your steering has been increased to full lock in each direction.
5. If at any point you see foaming in the reservoir, walk away and let the system “rest”. Then go back and continue the process.

This seems like a really slow, meticulous, tedious, and touchy system. Have others who replaced their pumps experienced anything similar?
 

No disintegrations

Well-Known Member
I work on hydraulic pumps often and it sounds bogus to me. Air bubbles alone should not be able to lock the valve. unless it has dirt or grit in it or other foreign material. I'm still in the wrong direction camp.
 

No disintegrations

Well-Known Member
I rewatched the video from earlier and something is troubling me. I'm not sure we are on the same page as far as pressure line etc. In video I'm not sure what I'm seeing and hearing. I can try on a bigger screen and check back later.
 

Tim_D

Active Member
On the first pump (which includes the video), I can't say that I am seeing flow whatsoever, in either direction of rotation. I only see what I perceive to be the fluid level on the pressure port rising when rotated CW, and falling when rotated CCW. Which seems to indicate to me that no pumping is actually occurring. And that is backed up by not observing any perceptible flow in the reservoir when the engine is running.
 

RmvBfrFlght

Well-Known Member
The direction of the pump ring affects whether it is a CW or CCW pump. Install it wrong and the pump won't pump. Here is the FSM directions on the pump ring, which is actually easy to check. Along with the factory bleeding procedure.

PS_PumpRing.jpg


PS_Bleed.jpg


RemoveBeforeFlight
 

captndave737

Well-Known Member
I’ve had my PS pump off and drained a few times and replaced once. Never had a problem bleeding using the factory procedure both before and after converting to hydro boost.
 

Tim_D

Active Member
The direction of the pump ring affects whether it is a CW or CCW pump. Install it wrong and the pump won't pump. Here is the FSM directions on the pump ring, which is actually easy to check. Along with the factory bleeding procedure.

View attachment 328253
RemoveBeforeFlight
So is the pump ring orientation the only thing that is different between a CW and CCW pump? If so, and my pump's ring is oriented upside down, I should be able to invert it and re-assemble, correct?
 

RmvBfrFlght

Well-Known Member
That is my understanding, although I have never verified this. I do know that on the pumps I've installed new seals on ('67 - '85) that there is a direction arrow cast into the ring. FSM states to place the ring in place so that the arrow points in the direction of rotation. This is on the earlier pumps that have the integral reservoir.

To check the '86-'87 CCW pump remove the retaining ring from the rear of the pump. Then remove the thrust plate. Can see the pump ring, if marks are up, I'd flip the ring over and try it.

RemoveBeforeFlight
 

TexasT

Texas, Where are you from
If you take the belt off and watch the reservoir while turning by hand will it be able to see the fluid move in the res? Turning it the other way make "waves" in the res? Not sure how fast the pump has to go but seems like it should move some at a slow speed.
 

Tim_D

Active Member


Ok, I’m officially pissed. I removed the pump this evening and took off the rear thrust plate (which is no easy task by the way). I found ID marks face-up on the pump ring, which means it was installed upside down according to the FSM.

I flipped it over and reassembled, but There seems to be more drag on pulley rotation in both directions, so I’m afraid I may have screwed something up in the pump.

Lares is gonna get an earful from me on Monday..
 

Boost231

What's An Intercooler
Staff member
Our pumps are reverse. You might have installed it forward. . I can't tell which way you have it now but it was probably correct before you changed it

Sent from my SM-G935T using Tapatalk
 

Tim_D

Active Member
Our pumps are reverse. You might have installed it forward. . I can't tell which way you have it now but it was probably correct before you changed it

Sent from my SM-G935T using Tapatalk
Yep I know. The reason I flipped the orientation of the pump ring was due to the excerpt from the service manual above, describing the orientation with respect to pumping direction.

I took the pump back apart one more time today and reassembled, taking care to make sure everything was right. I then put it all back together, bled per the service manual instructions above... And wouldn’t you know it, I now have power steering.

As I said, Lares is getting an unhappy call from me tomorrow. I ended up having to take the power steering system apart and reassemble four times, and I had to fix their pump. That is totally unacceptable!
 

RmvBfrFlght

Well-Known Member
...I took the pump back apart one more time today and reassembled, taking care to make sure everything was right. I then put it all back together, bled per the service manual instructions above... And wouldn’t you know it, I now have power steering...
Thank you for your feedback.

RemoveBeforeFlight
 

Tim_D

Active Member
Well, contacting Lares was very unsatisfactory. I spoke with their tech department, who pulled up the build sheet, and nowhere did that sheet specify the critical nature of the pump direction, nor the relatively easy method to ensure it's right. They claim their build instructions come directly from Saginaw, which I find had to believe based on no mention of direction of rotation, plus the fact that this specific part number is listed ONLY for 86-87 GNs and 89 TTAs.

I'm and engineer by trade. I know the value of making sure a design is sound, and methods used to ensure it. If Lares' only method to ensure robust design is a build sheet, they are missing critical design verification steps of actually trying the part on the intended application. This is a steering system, and product safety and liability are involved.

The only thing Lares said they will do is refund my money through Rock Auto, if I return the pump. Even though I have essentially helped them troubleshoot their design for the next guy.

Returning the part would mean I would have to disassemble the car again, go through another quart of power steering fluid spilled all over the lower part of the engine compartment, rent a pulley puller, box up and send the part back (at my shipping expense)... And then receive compensation for the original cost of the pump only. Then I'd still have to buy another pump, install it and bleed it etc. And the car would be down another week and a half.

I've already been through that process three times (doing it again would be a fourth). I guess what I am getting it as DO NOT BUY A GN POWER STEERING PUMP FROM THESE GUYS. It may end up being right when you get it, but only because an end-user customer provided them with information to make it right. They lacked the will to get it right themselves, which is a red flag for their other products.
 

TurboTnZ06

Go on red!
Buy an ac delco GM pump new, not some reman, no one will know that a GN/T is different and goes the other way, even if the box says so. BTDT. I run hydroboost and tried 2 remans, they didn't work, no pressure, went the wrong way. Bought a AC Delco new one and boom, worked perfectly, didn't even have to bleed anything, just dropped it in a filled it up.
 
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