Odd problem with bleeding hydro-assist

[miniwally]

Well the ram is the last thing in the system that is giving you probs and I have seen and heard of issues with getting them to fully bleed.

Remember when the truck is running it doesn't take much to foam the fluid.

 

[mrk5]

Yeah, I had switched to synthetic hoping it would give me a little more leeway in the foaming department. By now after having to switch so many things out and bleed different fittings it's only about half synthetic.

 

[Mike D]

Can you by pass the heat sink? The large surface area could hide a lot of air. Remove it from the system and bleed the ram as you mentioned. If everything starts to work correct then you found your culprit. If this is the case, tape one end and place the heat sink verticle ( in a bucket ) and manually fill. Tape that end and invert. continue topping off, taping, and inverting until no bubbles are observed. Make sure both ends are taped shut, now quickly unhook bypass ( use your finger to minimize fluid loss ) and reconnect heat exchanger. Tighten fittings and bleed ram. Good luck.

 

[mrk5]

Do you think the heat sink style would have that much trouble with air? Or are you thinking of a stacked plate cooler?

The heat sink cooler is straight through with find protruding into the passage. I have read that I should hold it vertical while bleeding because the internal passage is larger diameter than the fittings at the center of each end.

 

[BGKYK5]

I am no help at all, but I do have a question. Why is the heat sink style of cooler preferable to the stacked plate for PS fluid?

 

[mrk5]

It's not necessarily the heat sink style that's preferable so much as it is the flow through design. So the tube and fin style is supposed to be good, too.

All my knowledge on the subject is based on reading through forums. It is believed the stacked plate style creates more turbulence in the fluid as it returns back to the reservoir and this can aerate the fluid and maybe cause other issues too. FWIW, if you look at the websites for the companies selling hydraulic steering components, none of them sell stacked plate coolers.

All that being said, of course there are tons of people that run stacked plate coolers without any issues.

 

[Mudstud]

Couple things- I can't see your pics here at work so going blindly.

First off- is your remote reservoir mounted higher then the the factory res? If so, the air can get trapped inside the factory res. I have a friend who has a set up simular to this and he ended up brazing some sort of T valve onto the neck of the factory res so he could crack it and let it bleed out the air. You could also add a length of radiator hose to yours to get it above the level of the remote res and try it out.

Secondly, are the nipples on the ram facing straight up or back? If back then I could see where air may forever get trapped inside the ram. You amy have to remove one side of teh ram, spin the body up so the fittings are straight up and then cycle the steering.

Yea, the full syn fluid or straight hydro fluid I hear is best.

 

[mrk5]

The remote reservoir is higher than the factory reservoir on the pump. However, technically the highest point in my system is the hydroboost. I think I could see where the air could get trapped as you mention if the returns were still down on the pump, however they are plumbed to the remote reservoir in mine.

Actually, way back when I started this process I had the fittings on the ram clocked to about 10 o'clock and was told I needed to have them directly on top. So now they are right on top. The funny thing is that my initial successful run with only the ram installed the fittings were at 10 o'clock.

Thanks for the comments.

 

[mrk5]

Couple things- I can't see your pics here at work so going blindly.

First off- is your remote reservoir mounted higher then the the factory res? If so, the air can get trapped inside the factory res. I have a friend who has a set up simular to this and he ended up brazing some sort of T valve onto the neck of the factory res so he could crack it and let it bleed out the air. You could also add a length of radiator hose to yours to get it above the level of the remote res and try it out.

Secondly, are the nipples on the ram facing straight up or back? If back then I could see where air may forever get trapped inside the ram. You amy have to remove one side of teh ram, spin the body up so the fittings are straight up and then cycle the steering.

Yea, the full syn fluid or straight hydro fluid I hear is best.

After thinking about it some more, I would be curious to see some pictures of your buddy's setup if you can get them. Even if it doesn't help me, it still might be useful for someone else in the future.

 

[miniwally]

In a normal stock setup the hydro boost unit is the highest point anyways.

I think the problem is lieing with the ram and possible something with the box. I am only sort of joking about the 5,000 turns lock to lock thing to get it bled.

 

[70jimmy]

Shot in the dark here, bear with me.

So you only have one of the lines hooked up on the power steering pump and the other is blocked off so when you turn the wheel there could be a little lag time from when fluid is sucked out of the pump and new fluid fills from either the pumps reservior or the remote res??

Did you do any mods to the pump to increase fluid flow? A search on Kid Jethro Power steering pump mods will get you there. This was a huge help for mine.

Next stupid question are you 100% sure you have the lines hooked up correctly from pump to ram. I had mine backwards initially and it still kind of worked.

When I bled mine I put it on jackstands and with engine running went back and forth slightly keeping fluid full then slowly increased how much I turned the wheel about every 20 turns. If it bubbled a bunch I let it sit then refilled fluid if needed and continued. It finally didn't take anymore fluid and was bled out but it took forever. I don't have a remote res, or cooler, 2 wheel drive box factory with crossover and single ended ram.

Now you can try this stuff or say shut up noob.

 

[mrk5]

Shot in the dark here, bear with me.

So you only have one of the lines hooked up on the power steering pump and the other is blocked off so when you turn the wheel there could be a little lag time from when fluid is sucked out of the pump and new fluid fills from either the pumps reservior or the remote res??

There are 2 return lines, one for hydroboost and the other steering gear. Is that what you are referring to? Both returns go to the remote reservoir. The hydroboost return only flows when you depress the brakes.

Otherwise, the pressure side of the system is in series. It flows out of the pump to the hydroboost then down to the steering gear.

Did you do any mods to the pump to increase fluid flow? A search on Kid Jethro Power steering pump mods will get you there. This was a huge help for mine.

I actually have a high performance pump from PSC.

Next stupid question are you 100% sure you have the lines hooked up correctly from pump to ram. I had mine backwards initially and it still kind of worked.

Yeah, because I first installed the ram without changing the pump or reservoir. It worked fine on a trail run and 100+ miles of driving.

When I bled mine I put it on jackstands and with engine running went back and forth slightly keeping fluid full then slowly increased how much I turned the wheel about every 20 turns. If it bubbled a bunch I let it sit then refilled fluid if needed and continued. It finally didn't take anymore fluid and was bled out but it took forever. I don't have a remote res, or cooler, 2 wheel drive box factory with crossover and single ended ram.

I haven't even been able to get to the point of running the motor yet with the ram hooked up.

Now you can try this stuff or say shut up noob.

Nah, I appreciate all input.

 

[mrk5]

Solved

I finally succeeded in getting the system working.

I ended up using a procedure I found on Pirate4x4.com and modifying it a little.

1. Disconnect lines feeding ram from gear box
   • Cap fittings on the box
   • Place hose ends in jugs of p/s fluid deep enough to provide fluid to fill ram at full stroke.
2. Cycle steering approx 10 times with motor off.
3. Bleed hydroboost.
   • Diconnect ignition wire
   • Crank motor 5-10sec.
   • Depress pedal 5 times.
   • Repeat until air no longer comes out of return line
     • I pulled the return line off the reservior and put it in a can of p/s fluid. This makes it easier to see air bubbles.
4. Start motor cycle steering & brakes to make sure air is out of system.
5. Reconnect lines feeding ram.
   • Keep lines as full of fluid as possible - I used a turkey baster to top them off before connecting.
   • Make sure you monitor reservoir level to make sure level doesn't drop too low.
   • Crack fittings on ram to make sure air removed.
6. Start truck and let idle for about 2min without moving steering or depressing brakes.
7. If all is good for 2min, turn truck off and check reservoir level.
8. Start truck and cycle steering and brakes.
9. The end.

One thing I did additional, was between steps 5 & 6 I let the truck sit for 3 days to let gravity do its work to help me a little. Then before starting the truck I bled the hydroboost one more time because any air that gravity did push out will end up in the hydroboost since it's the highest point in the system. I figured I'd been trying to hurry the process the whole time, I might as well take a different tact and let things sit for a while.

I also removed the steering stops to make sure the ram was cycling fully.

 

[BGKYK5]

Saved for future reference. Glad you got it working.