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Hydro Assist Steering Problem

DirtRidinz71

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I just did a hydro assist on my 92 GMC 1500 with a ford dana 60 swapped under it and 38" boggers.

I'm using the stock Saginaw pump and box. I drilled and tapped the box the same as in the tech area here: Pirate4x4.Com - Extreme Four Wheel Drive


Using a 1-1/2"x8" cylinder, that I had to cut the fixed end off and rotate so that the fittings pointed up. I had the ram fully extended to keep the inner seals away from the heat of rewelding.


The hydraulic lines are 1/4" diameter

I also have a 4"x12" cooler that I have laying on the front bumper to keep it lower then the reservoir but its still close to being level with the center of the pump.


The reservoir is extended around 5" with a piece of rad hose and a top cut off of an old steering pump I had.


I hooked everything up and have tried bleeding it for hours with trying all different ways of doing it and it is still not working. The factory power steering is working as without the ram attached on one end the steering is easy, attach the ram and it feels stiffer. Raising the rpm does not seem to help and it never feels like the ram is helping with the steering but yet at full lock you can see it pushing out on the tie rod so it is getting decent pressure then.

The whole time the ram has been extending on its own after turning to the left to retract it. It only does this with the end unhooked and with it hooked up there is not enough pressure pushing it out to move the tires. Here is a video showing what it is doing, I just have the ram mounted on the bottom of the tab so it is easier to see in the video.



I'm at a loss, is it still air in the system? Or the seals in the ram allowing the pressure to leak by? The pump not having enough pressure? I did take the parts out of the old junk pump I had to do the "redneck ram mods" to it but haven't installed it yet.
Thanks for any help or directions to go with next.
 

Kay86K5

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I would try doing the pump mod first. Then see if it makes a difference. Usually air in the system is pretty easy to identify. When you turn the rig off you usually can hear a "bubbling" noise coming from the pump.
 

ktmoutfront

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I'm going to say that you have an issue with the way the box was tapped. When I have added hydraulic assist to trucks, the ram is static if the box is not being turned.
 

DirtRidinz71

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I would try doing the pump mod first. Then see if it makes a difference. Usually air in the system is pretty easy to identify. When you turn the rig off you usually can hear a "bubbling" noise coming from the pump.

I will do the pump mod tomorrow.
Defintly not getting any bubbling noise or fluid puking out when shutting the truck off

I'm going to say that you have an issue with the way the box was tapped. When I have added hydraulic assist to trucks, the ram is static if the box is not being turned.

Any idea what the issue could be. I drilled and tapped it just like the link from pirate showed?



Any thoughts on the 1/4" hydraulic lines being to small? I had thought in my research that is what some where using but I could easily be wrong :dunno:
 

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The line size is 1/4" all around? That would affect the slow ram going one way and fast the other. It does take more fluid to push out than to push in.

The ram is 1.5" but what is the shaft size?
 

big dan

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I'm going to say that you have an issue with the way the box was tapped. When I have added hydraulic assist to trucks, the ram is static if the box is not being turned.


Ill second this. Im no expert so I cant really tell you what is wrong but it seems like something in the box.

First one I did would turn all the way to the left on its own without me touching the steering wheel. It was a wrestling match to get it to go straight and right turns were out of the question.

Ever since then every box Ive done the ram doesn't move unless you turn the wheel.
 

AR_K5

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How long has it been since your pump was rebuilt? Is it squeeling at all? If so alway try either rebuilding or replacing the pump before modifying a weak pump that might just need fresh o rings. I was about to add hydro assist, rebuilt the pump for $14, no longer needed hydro assist.
 

DirtRidinz71

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The line size is 1/4" all around? That would affect the slow ram going one way and fast the other. It does take more fluid to push out than to push in.

The ram is 1.5" but what is the shaft size?

Yes both lines going from the steering box to the ram are 1/4". I think when I checked the shaft size it was around 7/8"

How long has it been since your pump was rebuilt? Is it squeeling at all? If so alway try either rebuilding or replacing the pump before modifying a weak pump that might just need fresh o rings. I was about to add hydro assist, rebuilt the pump for $14, no longer needed hydro assist.

The pump is old, been on the truck for quite some time but has never really shown any size of being weak turning the 38's, except for when in the deep mud/snow
I was just hoping to weld the front diff and not have to completely fight the truck to turn it
 

AR_K5

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Then dump the steering box, get an "orbital valve" aka steering control valve and go full hydo steering. IMO hydro assist is just 2 systems that overwork the power steering pump.

I was running 37"s on a 10 bolt, couldn't turn unless moving. I rebuilt the pump, then I could turn stop to stop on dry concrete no problem.
 
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colbystephens

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I don't think that modifying your pump should be your next step. You need to figure out what's wrong before you increase the pressure.

While I agree that it's probably not related to air in the system, what's been your process for bleeding your system? Mine was bled out and fully functional in about 15 minutes - maybe less. It wasn't a challenging part of the process.
 

DirtRidinz71

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Then dump the steering box, get an "orbital valve" aka steering control valve and go full hydo steering. IMO hydro assist is just 2 systems that overwork the power steering pump.

I was running 37"s on a 10 bolt, couldn't turn unless moving. I rebuilt the pump, then I could turn stop to stop on dry concrete no problem.

Full hydro is out of the question, rig still gets drove on the road and needs to pass a safety inspection

As it sits right now I can turn my 38's on pavement lock to lock easily too, just doesn't go so well when they are buried in slop.

I don't think that modifying your pump should be your next step. You need to figure out what's wrong before you increase the pressure.

While I agree that it's probably not related to air in the system, what's been your process for bleeding your system? Mine was bled out and fully functional in about 15 minutes - maybe less. It wasn't a challenging part of the process.

For bleeding, I hooked everything up, filled up the reservoir and with the truck off and on jackstands went lock to lock until the fluid stopped dropping and bubbling. Then started truck up, checked fluid level, and then went lock to lock many times
 

DirtRidinz71

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I tore everything back apart today to double check and see if anything appears to be wrong, nothing caught my eye. Measured the outlets in the fittings and hoses and they are 5/32" if that makes much of a difference?




I also pulled the cylinder apart no signs of a bad seal or blow by in it.



I did the pump mods and reinstalled everything, bled the system taking much more time then the first round. Started the truck up and got the ram moving and it is still acting the same way. The pump mods did seem to make an improvement in the factory steering atleast.

I ran out of time and wasn't able to spend a lot of time working it back and forth with the truck running but with no change in how it worked I lost motivation to keep going.

As soon as the ram retracts and I stop steering input it extends on its own, it isn't extending with much pressure since with it hooked up it doesn't try to turn the steering wheel any. Raising rpms is no help. With it hooked up and tires on the ground it just feels like the ram is getting no pressure until it reaches full lock then it seems to have enough pressue. I still have to adjust my stops, one side is hitting and you can see the ram flexing the tie rod so it acts as it is getting decent pressure then.

Anybody know what kind of pressure I should be seeing in the lines at the cylinder if I was to hook up a gauge to it?
 

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I am leaning towards a seal or something inside the box leaking internally and allowing fluid to move the ram and not seal enough to build pressure. I have to say I have never had a steering gear apart, so I would not know where to look.
 

DirtRidinz71

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I am leaning towards a seal or something inside the box leaking internally and allowing fluid to move the ram and not seal enough to build pressure. I have to say I have never had a steering gear apart, so I would not know where to look.

That is where I am thinking the problem is at too. There's not much else to it really. The only strange part is that with the ram unbolted the steering is good, I would think that if an internal issue with the box then the it would show in the steering?
I think I'll take the box off again this weekend and pull it apart.
 

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The stearing box is still mechanical, so it would work. Just not maybe the best it can.
 

colbystephens

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If you end up having to bleed it again, next time do it this way with a helper. :

1. Turn the wheels all the way one direction with the front end on jack stands.
2. Put a funnel in the end of the line that goes into the currently-closed side of the ram.
3. Fill the funnel with PS fluid.
4. Have a friend SLOWLY push the wheels the other direction to suck the fluid down while continuing the pour PS fluid into it.
5. When you reach the locked position in the other direction, attach the hose to the box and repeat going the other direction.

This will get almost all of the system primed before you even turn the truck on. You should be fully topped off within a few minutes afterwards.

You can also "prime" your PS cooler if you think it'll help.
 

6.2Blazer

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Are you basing all of this on only sitting in the driveway and turning the wheels a couple of times? Have you actually driven the truck or tried putting some load on the tires before trying to turn them, like maybe pull up against a curb and turn them? This comes from your comment that you could easily turn the tires lock to lock sitting still prior to the hydro-assist. If that is the case I wouldn't expect it to be any easier, and might actually feel a little stiffer based on the ram being a little on the slow side. On mine if you try to turn the wheel too fast you feel resistance because the ram can't react fast enough.
 

AR_K5

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This is an honest question since my state doesn't do inspections.

Some cars are made with factory full hydraulic and even drive by wire steering systems. Orbital valves will still push fluid even if your pump stops turning. Tractors use hydraulic steering, most construction equipment has hydraulic steering. It's not unsafe when properly installed so why can't it pass an inspection. I would think it would be safer and more likely to pass inspection than "hydraulic assist" which sounds more dangerous because of the drag mentioned in previous posts due to an overtaxed pump trying to run 2 systems that don't always get along. Personally I would think using the right control valve to push a double ended ram with two short drag links connected firmly to the axle and the knuckles would be more of an upgrade than a safety issue when compared to the modified gear box method. But thats just me.
 

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I had Howe full hydro matched dual end ram system. Was excelent wheeling. Driving the freeway at 65mph was flat out exhausting. And the constant thought of a line busrting and the going across the freeway was stressful. My 2c.
 

AR_K5

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I had Howe full hydro matched dual end ram system. Was excelent wheeling. Driving the freeway at 65mph was flat out exhausting. And the constant thought of a line busrting and the going across the freeway was stressful. My 2c.

Thats why the DOT requires high pressure lines be tested, to insure against spontaneous line failure. You have soft rubber lines on your brakes, do you worry about that every time you hit the brakes? Use reliable parts and proper installation and you won't have anything to worry about.
 
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