Steering problem...Help

[liquid diet]

Hopefully there are some GM mechanics here. Yesterday I was leaving Home Depot and out of the blue when I turned left it felt like I had no power steering. I can turn right all day long with no problem, turn left and I'm using everytning I have to keep turning the wheel.
I have no leaks, I've flushed out the steering pump and gearbox, still have the problem.
I'm leaning towards the pump but If that was it wouldn't it be hard to turn to the right also?
Any help would be greatly appretiated.

[Moneypitt]

I agree that the pump should affect both directions. There is a relief valve in the pump, but if it were bad, I think it would be bad both ways. So, it must be in the box itself. There has to be some sort of by- pass in the box, so thats where I would start looking. Try jacking up the f/end, and turning the wheels lock to lock w/o the engine running. Same? if not, start the motor and try it again. If it is the same w/o the pump running, then its gotta be either the box, or something in the steering linkage. If it works w/o the pump, then look at the pressure relief valve just inside the pump at the high pressure hose fitting.... Kind of a mystery, one way good, other way bad... I'm sure some GM guy is going to post the real answer you're looking for.......Moneypitt

[Kachina26]

What are we working on?

[liquid diet]

99 Z71
I jacked it up and it works no problem. Whats also kinda weird is its somewhat intermitent. I'll be in a left turn then all the sudden the pump or whatever will grab and I'll have power.

[liquid diet]

I've looked on the internet and i've seen some threads about an evo sensor next to the brake pedal. Supposedly it knows which way your steering colume is moving.
Going out to look

[liquid diet]

OK, looks like I don't have this sensor.
It also looks like the power portion of the gearbox is mounted to it. Old style power steering lines would go directly into the box. This style goes into a power module (or something) mounted to the box between the colume and gearbox. I was thinking that might be the problem

[Kachina26]

You do have the sensor, and it is the most common problem we have with p/s problems. It is located at the base of the steering shaft just above the "u-joint" coupler. This is inside the truck right above the firewall. It is directly above the clear rubber boot that goes around the u-joint assembly. The connector is 6-8 inches from the sensor toward the steering wheel on the topside of the column. It is a 3 wire connector. This sensor can be a real mother to change. Mostly because you are fighting the rubber boot the whole time. Basically you are going to push the rubber boot down and remove the pinch bolt that retains the intermediate shaft, then push the intermediate shaft down and out of the way. I would have the new part in hand so you can get an idea of how it goes on and off. Anyway remove the old sensor and have fun with the connector, install the new sensor and (here comes the easy part) put the intermediate shaft back on. IMPORTANTIMPORTANT DO NOT ALLOW THE STEERING WHEEL TO ROTATE WHILE IT IS DISCONNECTED FROM THE INTERMEDIATE SHAFT. YOU WILL DAMAGE THE AIRBAG SYSTEM!!!!!! PM me if you have any questions.

[liquid diet]

Thanks for the help Kachina. I'll try it tomorrow morning

[liquid diet]

Kachina,
I don't think I have this sensor.
http://www.***boat.com/image_center/data/500/932U-joint-med.JPG
http://www.***boat.com/image_center/data/500/932Shaft-med.JPG

[Kachina26]

Sorry I didn't get to you a little sooner, I had the old body style on the brain. You are correct and I apologize for putting you through the work. Check linkages for binding and any obvious obstructions, other than that I have no words of wisdom. I will do a little research and get back to you. Just wanted to hit you real quick before you went nuts.

[liquid diet]

I appreciate the help

[Kachina26]

Sorry for the bum steer (pun intended). No bulletins or other information other than normal diagnostics. You are most likely looking at a bad gearbox, but I would recommend a real diagnosis rather than my over the net guess. Especially since you are talking to a drivability guy. Our front end man had no words of wisdom either.

[liquid diet]

I've called both chevy dealers in town and they have no clue, and of course I get out my grease gun to lube up the front end and I'm out. So with my truck up on jacks I'll be calling a friend to get a ride to the store.
I'm probably going to replace the gearbox first

[Oldsquirt]

OK, I'm not a GM tech, but I am a master tech for another manufacturer. Your problem sounds like a classic control valve assembly issue. This is incredibly common on GM front drive products with rack-and-pinion steering. I am assuming your truck has R&P, rather than the old recirculating ball gearbox(my '01 GMC 2 wheel drive has R&P). I sure hope GM isn't going to start having issues with the truck racks.:frown:
The control valve is the section that you mentioned being "between the steering box and the steering shaft" in another thread. It contains a spool valve that is sealed to the housing with Teflon rings. What happens is that the aluminum housing will wear out. When you flushed the system you probably saw dark fluid with lots of very fine metallic particles in it, right? The contol valve is not serviced separately, only comes as part of the rack.
The best long term solution for the worn out rack is to find a reman rack where the control valve housing has been fitted with a stainless steel sleeve. During my days in an independent repair shop, I replaced plenty of FWD GM racks and we always insisted on the sleeved units.
If you get one from a wrecking yard, you will be buying one that is on it's way to doing the same thing yours did.
Hope this helps.

[Kachina26]

That truck still runs a gearbox, no rack and peanut.

[Oldsquirt]

Hmmm, that means same basic problem(control valve) but different cause. Hardly ever see control valve problems in cast iron gearboxes...
Kachina, he mentioned plumbing going to a valve above the gearbox. Got some kind of variable assist device on there? I'm going to have to check one of my buddy's trucks tomorrow. Curiosity is getting the better of me....:D

[Kachina26]

I do mostly drivability so I have to check one or a manual. My online password isn't working so I'll have to wait until tommorow. But I don't think so, the variable one used the sensor I mentioned earlier that he doesn't have. Most likely a gear box, I checked the diagnostics earlier but it calls for a pressure check and I'm sure he doesn't have that kind of eqpt on hand.

[liquid diet]

I agree. Tomorrow morning I'm going to take off that control valve and see if its FUBAR'd. I priced gearboxes today and their around $300. So I'd like to check out htis valve thing first.

[Oldsquirt]

Liquid Diet, can you be more specific about the "valve and plumbing" above the gear box? The control valve I spoke of is generally built-in and not serviced separately.
A picture would be quite helpful.:)

[liquid diet]

Also Kachina, since your a drivability guy.
My wifes truck is a 98 S-10 Blazer. She's getting bad gas mileage and the exhaust pipe is a little wet. Obviously running rich, probably an o2 sensor. But of course she has 4 and their 90 bucks a piece.
Can't I ohm each one out to figure out the bad one or ones?
I've been told the ones before the cat usually go bad first.
I also bought a new air filter and fuel filter to change.

[liquid diet]

Squirt,
On old vehicles the power steering lines would go directly into the gearbox. My lines go into that valve before the gearbox. I think the valve probably has certain holes or something used for when you turn left or right. My guess is its slightly clogged or there's some metal floating around in there, which would explain why its somewhat intermitent.
I would post a pic, but I'm at work.

[Oldsquirt]

L D, don't test an O2 sensor with an ohmmeter! (unless you are testing just the heater circuit).
It's the ones AHEAD of the cat that are used for fuel control. The post-cat sensors are there primarily to monitor catytic convertor efficiency.
Putting a scan tool on the vehicle and viewing the data stream would save you guessing at what might be wrong and save you time and money in the long run.
As far as the steering gearbox goes, I'm plenty familiar, just haven't seen any late model GM stuff. The symptoms you describe are of a classic control valve problem. I'm concerned that GM may have added an extra valve assembly ahead of the control valve. Am I correct in my assumption that there are lines running from the valve you describe into the gearbox?
Boy, I really want to know that looks like. You've really got me curious.:D

[liquid diet]

No, there's no lines running from the valve to the box.
The pressure line comes from the pump into the top of the valve and the return line is right next to it going back to the pump. It has two bolts holding it onto the front of the gearbox

[Oldsquirt]

OK, that's just a slight revamp of the standard design. That would be the control valve, but I still doubt it is serviced separately. I know none of our older boxes were serviced any way but complete, even when the valve appeared to be removable. All we have on our stuff now is R&P. GM may just surprise you though.
Curious. Is that valve assembly aluminum or cast iron?
Keep us posted.

[Kachina26]

Originally posted by liquid diet
Also Kachina, since your a drivability guy.
My wifes truck is a 98 S-10 Blazer. She's getting bad gas mileage and the exhaust pipe is a little wet. Obviously running rich, probably an o2 sensor. But of course she has 4 and their 90 bucks a piece.
Can't I ohm each one out to figure out the bad one or ones?
I've been told the ones before the cat usually go bad first.
I also bought a new air filter and fuel filter to change. What engine do you have? Better yet what is the 8th digit in your vin # ? One more thing what is the mileage? I have a few things you can check if it is the motor I think it is.

[liquid diet]

I'll post a pic of the box in the morning and find out what its made of.
I know its a 4.3 not sure of the 8th digit, I'll check when I get home. I think it has around 75,000.

[liquid diet]

8th digit is a W and it has 86,000
Its 1:30 in the morning, time to go to bed and start over in the morning with my truck:sleeping:

[liquid diet]

http://www.***boat.com/image_center/data/520/932P1270003-med.JPG
http://www.***boat.com/image_center/data/520/932P1270001-med.JPG

[liquid diet]

http://www.***boat.com/image_center/data/500/932power_valve-med.JPG
Now I need to find out if i can get those nylon o-rings. If not guess its a new gearbox

[Oldsquirt]

Glad you found it! Hope you can get those rings. Wonder why they went bad?

[liquid diet]

Well, new gearbox is in and everything works fine.
Thanks for all the help and info Kachina, Squirt and everyone else good to have the truck back on the road
:D :D :D :D

[Kachina26]

Sweet, too bad it cost a chunk of change:( Lemme know how the s-10 turns out.
Hey Oldsquirt, what manufacturer do you work for?

[DORIGHT]

I take it this is not a common problem, was a rebuild kit for the box available?

[JetBoatRich]

Nice job, I never seen one go bad:confused: what caused it:yuk:

[liquid diet]

No rebuild kit available, tried Autozone, Checkers, Pep Boys, Mom & Pop stores, GM, no one could get the o-rings.
New gearbox was $311.00
Couldn't tell you how this happen, out of the blue leaving Home Depot the p/s to the left quit.:confused:
Works like a champ now:D