Steering Freeze Up

[bobedson]

98 issue since new, no one can figure it out. Anytime temperature falls below freezing and I have to leave my truck out in the cold I come out in the morning and can't move the steering. Locked up, serious muscle required to turn the wheel like no pressure is getting through the Hydroboost or to the steering gearbox or something in the steering box is freezing up. Never happens in warm weather. Have changed the PS pump, Hydro Boost, fluid to synthetic, running out of ideas. After a lot of muscle and a few minutes of trying to move the wheel all of the sudden it breaks loose and becomes normal. Have checked for leaks, water in the system that could be freezing, down to trying to change out the steering gear box. Any ideas would be helpful.

 

[Joe Mc]

Since it appears you think it could be fluid pressure related, when cold and before muscling the steering wheel, if safely able, pop in N and see what your brake pedal does. Is it super hard, doesn't want to budge? Don't try to force it down just see if it feels normal. If it too is hard like steering then you'll know if it's whole fluid system, if not then just in steering circuit. Cold does weird things to metal parts, check & psi regulating valves causing them to stick. I'm thinking you issue might be internal to the pump, I don't exactly recall for sure, but I think the pump discharge port has a spring that holds a ball to maintain pressure discharge. Perhaps the ball has a worn in ring on it that causes the ball to stick not allowing psi out for a period of time?
You should be able to place wrench on pump port where line connects then wrench on line nut and remove line, if you can plug hose you'll be able to reduce leakage and possibly not have to go thru entire system bleed process. Once line is free the port on the pump the fitting/port/regulator valve can be removed, careful not to damage reservoir on pump when wrenching port off, a quick firm tap on wrench should break it loose. Then you should be able to visually inspect parts. Check FSM for possible trouble shooting procedure. Some years back I saw a thread here describing stock regulator spring height and stretching the spring to a suggested height would provide more steering assist. Don't think you need "more assist" just need to figure out what is sticking. I think the brake hydro unit may have a check valve too? Check FSM before doing anything, maybe you can find an online exploded view of components that'll show check and reg valves. Hope this helps somewhat

 

[bobedson]

Since it appears you think it could be fluid pressure related, when cold and before muscling the steering wheel, if safely able, pop in N and see what your brake pedal does. Is it super hard, doesn't want to budge? Don't try to force it down just see if it feels normal. If it too is hard like steering then you'll know if it's whole fluid system, if not then just in steering circuit. Cold does weird things to metal parts, check & psi regulating valves causing them to stick. I'm thinking you issue might be internal to the pump, I don't exactly recall for sure, but I think the pump discharge port has a spring that holds a ball to maintain pressure discharge. Perhaps the ball has a worn in ring on it that causes the ball to stick not allowing psi out for a period of time?
You should be able to place wrench on pump port where line connects then wrench on line nut and remove line, if you can plug hose you'll be able to reduce leakage and possibly not have to go thru entire system bleed process. Once line is free the port on the pump the fitting/port/regulator valve can be removed, careful not to damage reservoir on pump when wrenching port off, a quick firm tap on wrench should break it loose. Then you should be able to visually inspect parts. Check FSM for possible trouble shooting procedure. Some years back I saw a thread here describing stock regulator spring height and stretching the spring to a suggested height would provide more steering assist. Don't think you need "more assist" just need to figure out what is sticking. I think the brake hydro unit may have a check valve too? Check FSM before doing anything, maybe you can find an online exploded view of components that'll show check and reg valves. Hope this helps somewhat

 

[bobedson]

Thanks, the brakes in fact are part of the issue, when the problem occurs the brakes don't work either, hard pedal and no boost. Thought the problem might be in the hydroboost so it is now been replaced with no change. PS/Vacuum pump assembly was replaced last year due to pump failure but that didn't fix the problem either. I suspected a bad reman pump but when we changed the pump same problem, no change. Of course could be two bad remans, never happened before right? I did check the filter screen for debris but none found. With the pump, hydroboost, master cylinder replacements the entire system has been flushed, refilled and bled multiple times, no debris found and fresh fluid each time. I am down to wondering if there is some poppet valve inside the steering gear box that is getting bound up in cold weather and not allowing the fluid to move through but I think the fluid goes from pump to hydroboost then back to steering box and return. Since the problem affects both steering and brakes not sure where else to turn except replace the pump again as well as replacing all hoses to see if there is a blockage somewhere that can happen only in cold weather. Once I can break the lock in the morning after a cold night it works fine the rest of the day so warm fluid is getting through somehow. Frustrating, this problem has been there pretty much since new but not really recognized or a problem the first several years since I lived in a warm climate.

 

[DavidC]

Someone on here went through 2 pumps before getting a good one.

 

[bobedson]

Yeah, thanks David, have given that a lot of consideration. I guess my thinking has been the problem was there before with the original factory pump that ran 230,000 before it failed. Went through 2 replacements, first one leaked like a sieve, both were remans. Replacing with factory new is hugely expensive which I would do if the original hadn't lasted for years and had the same problem. The only pieces left from original are the steering box and hoses which is why I am thinking there might be something in the steering box that is causing the problem. By the way I see your BUFF picture, you a BUFF driver?

 

[DavidC]

Aircraft Electrician B-52 and KC-135 primary but we worked on anything required, Fighters, Helo's etc.

 

[bobedson]

Cool, I was a helo driver in the army many years ago and retired flying Boeing 777 for the airlines. Always wanted to get my hands on a BUFF, serious American iron.

 

[Joe Mc]

So it does impact brake circuit as well as steering and only when cold. Is "cold" at 50° or lower, more like 30° or lower, or after sitting all night at 70° +/-? When it does the lock up before you wrench the wheel can you hear any unusual noise from the pump, like a whirring sound similar to an old Ford when low on fluid? This is perplexing and has my mind going too. Seems as if something is hampering fluid delivery and only when cold, got to be a check or something somewhere. Now you got me going, time to pull out the FSM and do some pondering. Thanks....LOL

 

[DavidC]

Thank you for your service. The BUFF is a great piece and a lot of fun to work on.

 

[Joe Mc]

I'm at a loss, sorry. FSM steering diagnosis and testing section pretty worthless = condition- difficult to turn wheel sticks or binds, possible cause #6 column shaft coupler binding (wouldn't impact brakes) of course correction replace coupler. #7 steering gear worn or out of adjustment correction repair or replace. Like I said worthless. In the steering gear disassembly and assembly section it shows balls in return guide, mentioning there are 24, 12 black 12 chrome, black smaller than chrome. States they are to be installed alternately. Since this locking has always (at least when cold) been the case perhaps when gear was being put together one ball wasn't installed alternately? Sorry not much help and a steering gear ain't cheap and not even a little bit of fun to r&r. Wonder if somehow the preload adjustment was fooled with and too tight?

 

[bobedson]

So it does impact brake circuit as well as steering and only when cold. Is "cold" at 50° or lower, more like 30° or lower, or after sitting all night at 70° +/-? When it does the lock up before you wrench the wheel can you hear any unusual noise from the pump, like a whirring sound similar to an old Ford when low on fluid? This is perplexing and has my mind going too. Seems as if something is hampering fluid delivery and only when cold, got to be a check or something somewhere. Now you got me going, time to pull out the FSM and do some pondering. Thanks....LOL

Yeah, has been frustrating. Only when cold, below freezing. If really cold, like 15-20 it will freeze up after sitting for a couple of hours, otherwise it never freezes up sitting in the garage even with sub freezing temperatures outside. Worse of course if it is sitting outside with a little wind blowing. The only thing I can come up with is possibly a really tight ball or poppet valve inside the steering box case so when the case gets really cold it squeezes the valve to not let it open. Reality is when cold fluid is not flowing freely because it also affects the hydroboost so no brake boost either. That is why I have suspected the pump or valves on the pump freezing up and not allowing fluid to flow. I'm thinking of replacing the pressure and return lines possibly one of them is restricted in flow or contracting in the cold to the point of closing off the pressure. Crazy but running out of options.

 

[bobedson]

I'm at a loss, sorry. FSM steering diagnosis and testing section pretty worthless = condition- difficult to turn wheel sticks or binds, possible cause #6 column shaft coupler binding (wouldn't impact brakes) of course correction replace coupler. #7 steering gear worn or out of adjustment correction repair or replace. Like I said worthless. In the steering gear disassembly and assembly section it shows balls in return guide, mentioning there are 24, 12 black 12 chrome, black smaller than chrome. States they are to be installed alternately. Since this locking has always (at least when cold) been the case perhaps when gear was being put together one ball wasn't installed alternately? Sorry not much help and a steering gear ain't cheap and not even a little bit of fun to r&r. Wonder if somehow the preload adjustment was fooled with and too tight?

Yeah, I looked through my manuals and came up with the same conclusion. Nothing fits the problem and you are right, replacing a steering box is expensive and a pain, sure hate to try it and find out that wasn't the problem. Of course I guess I can always hope it never freezes in Texas again

 

[BigPapa]

I guess it's possible, but if the issue affects the brakes AND the steering, I doubt it's the steering gear.

 

[bobedson]

I guess it's possible, but if the issue affects the brakes AND the steering, I doubt it's the steering gear.

Yeah me too. Just really strange that replacing all the pressure components didn't help. Doesn't seem to be a fluid flow issue since each time a component was changed everything was bled and got the air out. Simple description would be somehow water was getting in and freezing somewhere but everything is tight and no leaks. Not too many other parts to change at this point. Winter is about over so probably can't track it down until next year.

 

[fbuchynski]

I am not familiar with the hydroboost system so this may not be a valid idea. Can you isolate the steering from the braking functions to see which one is causing the problem?

 

[bobedson]

I am not familiar with the hydroboost system so this may not be a valid idea. Can you isolate the steering from the braking functions to see which one is causing the problem?

No, the power steering pump/vacuum pump is an assembly. PS pump shoots pressure up to the hydroboost valves which provide pressure for power brakes and a return line to the steering system. Can't isolate the two.

 

[fbuchynski]

Ok, forget that idea

 

[pdfiddler]

complete fluid flush maybe?

 

[Tuesdak]

I suspect you are using reman parts. For the PS pumps either get NEW or pull one from a wreck in a junkyard. The junkyard one was likely working at impact. Reman is something that was ruined and maybe repaired properly or not. If not the debris from a possible pump burn up will dust the entire system. Last reman pump I will ever use was a snow globe in the oil and the shaft quit touching the seal. So in 30 min it had dusted the system and started leaking from grinding new clearances. I had to replace the HB, PS pump, steering box, hoses, flush the cooler, and added a in line filter.

Off the cuff fluid flow goes from pump to the HB unit: then to the steering gearbox. This means the brakes get dibs on pressure and can take it all leaving nothing for steering.

IF the brakes worked you could look at the steering box, but, they don't. Pump or HB...

So something like a kinked return hose off the hydro booster keeping the brakes applied is possible. So is a leaking accumulator in the HB. Are the brakes soft or firm to apply before engine start after sitting overnight?

If the accumulator is leaking down it's going to want to be charged up as soon as the engine starts. A weak pump may not be able to generate enough pressure and they sit fighting each other. Pump can't get any flow and accumulator has the flow blocked waiting on pressure.

The internal pressure relief valve on the pump may be wrong: for a gasser with PS only and set too low. Rebuild outfits don't take the time to care about special diesel settings in the PS pump for the HB. So the pump may be bypassing through a weak gasser relief valve until the HB accumulator can charge up and release the pressure to the rest of the system.

What oil you running in the system? Had a GM that had a TSB to use a revised synthetic fluid due to stiff steering.

Some outfits can put a pressure gauge on the pump. IMO start with verifying proper oil then replace the PS relief valve to make sure it's the proper diesel pressure part. If it's a reman pump odds are good it's just a junker with a poor paint job: replace it with better.