Sudden Power Steering Problem

[saxart]

I'm having a problem with the power steering on my '70 C-10. Hoping someone has some thoughts.

The truck was recently put into service after getting a new crate engine, rebuilt power steering pump, and red-head steering box. I purged the box exactly like Red Head's website instructs. (Jack up front of truck and work steering back and forth 15 times with engine off, do it again with engine running, all while topping up the pump with fluid when needed.)

The air-purge went fine, and at the start of the maiden voyage the steering was really nice. Smooth, easy turning and linear across it's travel. About 2 miles into the trip, the steering got VERY stiff. I pulled to the side of the road to check the power steering fluid level, expecting it to be low, but it was not, so I nursed the truck home to investigate.

After getting the truck back up on jack stands and working the steering back and fourth, it's still VERY hard to turn the wheel, and the steering box pukes fluid out of the top of the reservoir. I thought maybe there was still air in the system, so we kept working the steering box back and fourth about 30 times with no improvement.

What happened here? Could the Red Head steering box be bad?

[saxart]

Bump... Could really use some help with this one.

I called Redhead today. They were very nice, but pointed to it not being fully purged yet. Told me to put it up on jackstands (non-running) and keep spinning the steering wheel back and forth between hard left and hard right. Probably did about 100 cycles back and forth, but every time we fire it up and try it, still no power steering. Something isn't right here.

Here's what I see... When you turn the steering full to the passenger side, the fluid level in the pump body will rise and overflow. When you turn the steering full to the driver's side, the fluid doesn't rise. This is what made the folks at Redhead thing it's still full of air. Any thoughts? Could the steering box be bad? Would a power steering filter cause it to have difficulty purging the air?

[saxart]

A couple hundred views, but nobody has any thoughts?

Here's an update. Maybe this will spur some ideas. Today I pulled the hoses off the pump and the steering gear to check for obstructions. There were none. (air blows through them) While I had the lines removed from the steering box, I turned the steering wheel from one side to the other. While doing this fluid shot out of the low pressure port of the steering box, but fluid wouldn't come out of the other (high pressure) port. Is that a problem? It seems as though there is a small spring loaded check-valve just inside the high pressure port. (It goes up and down in there if I gently poke at it with a thin wooden dowel) I guess that is there by design.

Since that didn't seem to help, and Redhead still says there must be air in the system somewhere, I picked up one of these:

https://www.lbusupport.com/asp/distr...0_bulletin.pdf

I used my hand held vacuum pump to apply 20 inches of vacuum. It held that vacuum overnight, so I know that air isn't still getting into the system.

I'm very perplexed. Could something be wrong with this steering box? It worked for 2 miles on the truck's maiden voyage, but then quit with the steering becoming very stiff. Redhead says there is still air somewhere in the system, but it's been like this for about 4 weeks (can't drive the truck) and I've probably cycled the steering back and forth hundreds of times now trying to purge the air that's supposedly in there. (Both with the engine running and not running.)

If you have any experience purging a power steering box, please chime in!

[Moose Monkey]

Photos of lines connected to box. Maybe backwards? Was the Box centered when pitman arm installed? Know your pain, just blow manual box in my ride

[Steeveedee]

Yeah, this is out of my area of expertise. I would say that getting stiff after the air being bled out indicates that something failed. What, I couldn't say without looking in the manual. Do you have a manual for your truck? Go here and download it for free, if not:

http://67-72chevytrucks.com/vboard/s...d.php?t=558016

There will be a troubleshooting section.

[Kw69]

I think that it should have purged itself by now. Just a quick thought...were there any caps on the connecting points or hoses to keep dirt particles out prior install? Is it a possibility that dirt got in the system or did one of those caps have a piece break off and get lodged? Again just throwing ideas your way. I’m not sure unless u have an issue with the rack.

[Boog]

'after getting a new crate engine, rebuilt power steering pump,'.
Could your problem be in that "rebuilt" power steering pump. Could the pressure valve in the pump have failed?

[suburban99]

I had a similar issue with my K10 LS swap. Thought the pump was shot as it was original to the engine. Got a junkyard replacement off a Tahoe and it didn't work. Got another replacement pump and it didn't work. It was the recently replaced steering gear...internal failure. Got it replaced under warranty.

[rsgt]

I replaced my box and pump and did all the purge and it was working good. About 8 miles it was making noise and got stiff. Tried to purge again with no luck. I bought a can of seafoam trans tune for power steering and transmissions. I put that in and did the purge thing again and it started to work good. Then I flushed the system and put in PS fluid and it has been good ever since.

[frank69]

I had shaft break inside pump on my 99 1500, everything looked normal just real hard to steer

[custom10nut]

Sounds like something let loose in the steering box. Troubleshoot it working from the Column.
Unbolt the rag joint, turn the wheel. If it’s free then the column is good.
Take the belt off the pump, start it up and turn the wheel. If it’s still real stiff its definitely the steering box.

[saxart]

Wow, thanks for all of the thoughts. I appreciate it!

I'll try to answer all of the thoughts & questions so far:

1) I double checked the routing of the power steering lines, they are correct. (Was actually hoping they would be wrong as that would be an easy fix, but the fittings are different sizes, so it's impossible to do.)

2) While it's possible that dirt could have gotten into the system somehow, it's highly unlikely. I did change out the fluid when I checked for blockages in any of the lines, and the fluid looked clean. (The lines are all brand new by the way)

3) I'm inclined to suspect the pump, but it's not leaking a drop. With the engine off, if we have the fluid filled to the correct level, it will purge about 1/2 cup of fluid out of the top of the pump body when I turn the wheel to the right with the wheels jacked off the ground. (For some reason, it's only when turning to the right that it does that. This is what makes me think it's the gear.)

KEEP THE THOUGHTS COMING!!

[saxart]

Double post.... Sorry

[saxart]

So, one last question as I fight with this power steering issue. It's to the point that I'm done trying to "bleed" this thing, I think it's time to figure out if it's the pump that is bad, or the steering gear. I'm leaning toward the steering gear. Here's why....

With the engine off, when I turn the wheel to the RIGHT, it will purge about 1/2 cup of fluid out of the top of the pump. The guy @ Redhead maintains that there is still some air in the system, but I've been trying to bleed this system for about 4 weeks now and it still does the same thing. I'm pretty sure it's not ingesting air through the pump or steering gear because I used my hand vacuum pump to put vacuum to the system and it will hold 20-inches of vacuum for DAYS. If it was letting air in the system, that vacuum would bleed off in a few minutes, right?

So, like I said, it's at the point where either the pump or the steering gear is bad. I think it's the steering gear. What do you think?

[Boog]

If it was me, I would try another pump. That one is a “rebuilt”

[saxart]

Originally Posted by Boog

If it was me, I would try another pump. That one is a “rebuilt”

Thanks Boog. Yes, I rebuilt it myself, so that does make me suspect my work more than the steering gear. (I’ve rebuilt garden tractor hyd pumps before, but never a power steering pump)

Having said that, I can’t figure out how an issue with the pump could show itself as an issue if the pump isn’t turning (over flowing fluid with the engine shut off).

[rsgt]

When I purged mine with the seafoam trans tune I turned the wheel super slow back and forth just barely moving the wheel. It took awhile and was I surprised when it started to have power.

[saxart]

Well..........

I found the problem. After considering everything, I came to the conclusion like many of you already have, that something was mechanically wrong. It had to be either the pump, or the steering gear. I figured the steering gear would be more difficult to swap out due to shipping in Washington state, so I started with the pump and picked up a rebuilt one from NAPA. One of the first bolts I removed on the old pump was the one that hides under the pulley. As I was trying to sneak it out between the bracket and the pulley, the pulley slid outward about 1"! While it made removing the bolt much more convenient, it wasn't supposed to do that. At that point I just yanked the pulley and shaft assembly out as it was easier to remove the pump that way.



Although I'm no expert on these things, I have rebuilt some pumps before, and this seems odd. It looks like the the pump rotor somehow came off the end of the shaft. Not sure how that's even possible??? If I remember there was a snap-ring on that. Hmmm... Probably shouldn't have used the old one I guess.



Thank GOD I had put an inline power-steering filter on this set up originally as it caught a fair amount of the grey metal dust on the magnet inside it.

The system is all back together and buttoned up. I spun the steering back and forth about 20 times (engine not running) now i'm just waiting overnight for any bubbles to settle out, then I'll do it again, and it should be good to go.

Thanks again for all of the help with this!

[Boog]

Yeah, that'll do it. I've never used an inline steering filter but I see it paid off for you in this instance.

[Moose Monkey]

Yaaaaaaaa!