Hydro Steering Assist

...I picked up the PSC dual cooler kit but only ordered one radiator style cooler since I don't need the 2nd one for the transmission. Also, the advice Drew@Offroad Evolution gave me, as well as SaddleTramp was to avoid the Derale inline fin style cooler. They don't cool as well, and can have the potential to trap air, making it difficult to fully bleed. FYI heat is the #1 killer of hydraulic systems.

I wasn't given this advice about the fin style coolers when I bought one and installed it, it was obvious that it trapped air and I couldn't bleed the system properly. I replaced it with the dual cooler bracket/single radiator from PSC and added a fan for when off-roading! I went to a local club event and the owner of redneck ram was there and asked why I had a cooler, I told him my reasoning, he went on and said that hydro assist systems run hot and that a cooler usually isn't necessary
 
Very good thread,

This is my next mod, have a PSC ram brand new in the box waiting to get fab up to go on the jeep. I purchased the fin type cooler also to run with the setup, but seems to be a lot mixed reviews on running. Now I need to pickup a PSC pump, tapped gear box and have all the lines made up.
 
I wasn't given this advice about the fin style coolers when I bought one and installed it, it was obvious that it trapped air and I couldn't bleed the system properly.

That's good to know ahead of time. Being that I have the finned cooler already I think I'll drill & tap a small bleeder hole on the top of it before I install to help bleed the air out of it. Maybe even mount it with a couple washers on one end that the bleeder is on to help it purge a little better.
 
Sorry, I beg to differ my good man. Mine was howling pretty good without it. Once off the trails and back onto paved roads it cooled back down & was fine. These systems run really hot and the cooler can't do anything but good. Using the proper fittings one shouldn't have any issues with leaks.

So I did some research on Hydraulic systems and this is one of many resources:

http://www.machinerylubrication.com/Read/531/hydraulic-root-causes

The howling you hear is cavitation and has little to do with heat and really is coming from your pump. Read "Cavitation occurs when the volume of fluid demanded by any part of a hydraulic circuit exceeds the volume of fluid being supplied. This causes the absolute pressure in that part of the circuit to fall below the vapor pressure of the hydraulic fluid. This results in the formation of vapor cavities within the fluid, which implode when compressed, causing a characteristic knocking noise."

Meanwhile, further in the article is states: "High fluid temperature can be caused by anything that either reduces the system’s capacity to dissipate heat or increases its heat load. Hydraulic systems dissipate heat through the reservoir. Therefore, the reservoir fluid level should be monitored and maintained at the correct level. Check that there are no obstructions to airflow around the reservoir, such as a build up of dirt or debris." The PSC extreme kit comes with a large reservoir. ORE mounted this on the MORE dual battery tray by repositioning the battery against the firewall and then mounting the reservoir where the 2nd battery would normally go. This then allows a lot of air flow for the entire system to cool.

So it would seem there might some other issue with your situation. Is your reservoir mounted in front of the pump, requiring cutting into the stock airbox? This might explain your apparent need for a cooler because the reservoir does not have enough air moving over it.
 
Last edited:
So I did some research on Hydraulic systems and this is one of many resources:
So it would seem there might some other issue with your situation. Is your reservoir mounted in front of the pump, requiring cutting into the stock airbox? This might explain your apparent need for a cooler because the reservoir does not have enough air moving over it.


Yeah, that makes sense and this could be the case - here is where my reservoir is mounted. (disregard the red arrows - they don't mean anything in this context) There is little airflow around it. In fact, there is none. I was extremely conscientious of all of the fluid levels on my trip so I know that wasn't an issue. In fact I had to wait til evening to even be able to touch the reservoir cap to check the level. In my particular situation I think the cooler makes sense. With the reservoir mounted somewhere that is exposed to some airflow I would think maybe you wouldn't need one.

Thanks for doing that research!

ps res.jpg
 
Yeah, that makes sense and this could be the case - here is where my reservoir is mounted. (disregard the red arrows - they don't mean anything in this context) There is little airflow around it. In fact, there is none. I was extremely conscientious of all of the fluid levels on my trip so I know that wasn't an issue. In fact I had to wait til evening to even be able to touch the reservoir cap to check the level. In my particular situation I think the cooler makes sense. With the reservoir mounted somewhere that is exposed to some airflow I would think maybe you wouldn't need one.

Thanks for doing that research!

View attachment 221490

I agree, in that install, a cooler would be perfect. In fact, I like that setup if I was ever going to run a dual battery configuration. Looks very clean and well done.

Speaking of checking levels, I learned later on after install was how high the level should be. I was overfilling it and wondered why I would get fluid out of the breather tube. JeepFan recommended that I fill only to the top of the bolt. This solved the fluid coming out of the breather tube.
 
So I did some research on Hydraulic systems and this is one of many resources:

http://www.machinerylubrication.com/Read/531/hydraulic-root-causes

The howling you hear is cavitation and has little to do with heat and really is coming from your pump. Read "Cavitation occurs when the volume of fluid demanded by any part of a hydraulic circuit exceeds the volume of fluid being supplied. This causes the absolute pressure in that part of the circuit to fall below the vapor pressure of the hydraulic fluid. This results in the formation of vapor cavities within the fluid, which implode when compressed, causing a characteristic knocking noise."

Meanwhile, further in the article is states: "High fluid temperature can be caused by anything that either reduces the system’s capacity to dissipate heat or increases its heat load. Hydraulic systems dissipate heat through the reservoir. Therefore, the reservoir fluid level should be monitored and maintained at the correct level. Check that there are no obstructions to airflow around the reservoir, such as a build up of dirt or debris." The PSC extreme kit comes with a large reservoir. ORE mounted this on the MORE dual battery tray by repositioning the battery against the firewall and then mounting the reservoir where the 2nd battery would normally go. This then allows a lot of air flow for the entire system to cool.

So it would seem there might some other issue with your situation. Is your reservoir mounted in front of the pump, requiring cutting into the stock airbox? This might explain your apparent need for a cooler because the reservoir does not have enough air moving over it.

You nailed it with Cavitation. Anyone who deals with hydraulic systems knows the sound well. It is almost always caused by a restriction on the suction side of the pump that causes a vacuum against the low side while trying to pressurize the high side. Pumps won't last very long in this condition, and the cavitation its self induced heat to the system as the oil can't flow freely.
 
You nailed it with Cavitation. Anyone who deals with hydraulic systems knows the sound well. It is almost always caused by a restriction on the suction side of the pump that causes a vacuum against the low side while trying to pressurize the high side. Pumps won't last very long in this condition, and the cavitation its self induced heat to the system as the oil can't flow freely.

I am highly considering going in this route so maybe I missed it but how do you prevent/ fix this problem?
 
The flow to the suction side of the pump needs to be unobstructed. This includes adding filters and routing a hose so that its I.D. Narrows or kinks. You can also get similar symptoms from a suction side hose that is not tight enough ( suction can pull air into system without ever visibly leaking oil out ) Use the proper fluid for the pump. Any add on items filters, coolers, etc are usually best installed on the return line to the reservoir.
 
I am highly considering going in this route so maybe I missed it but how do you prevent/ fix this problem?

If you're considering going hydro steer, you'll save your self a lot of headaches by investing in a full system , properly ported steering box, pump with correct size pulley, reservoir and cooler.

The reservoir to the pump is gravity fed so you want to make sure the line is a little higher than the pump's intake port.

make sure the system is fully bled, doesn't take much air to cause cavitation (I fought this with mine and turns out the installer used a different type fitting that was allowing a non-visible leak on the hose and air in.)

PSC make a good system and what I've been using for 2 yrs...maybe 3, I've got friends who use Redneck ram with good results.
 
If you're considering going hydro steer, you'll save your self a lot of headaches by investing in a full system , properly ported steering box, pump with correct size pulley, reservoir and cooler.

The reservoir to the pump is gravity fed so you want to make sure the line is a little higher than the pump's intake port.

make sure the system is fully bled, doesn't take much air to cause cavitation (I fought this with mine and turns out the installer used a different type fitting that was allowing a non-visible leak on the hose and air in.)

PSC make a good system and what I've been using for 2 yrs...maybe 3, I've got friends who use Redneck ram with good results.

I ordered the PSC complete system from Trail Jeeps but did not get the cooler. To be fair, the only time I had the cavitation happen was in Moab when it was 105*. I'm tempted to leave system as-is & see how it does at Rausch Creek in a couple weeks.
If it happens again in goes the cooler.

I just wonder how many other guys out there running this setup have had heat issues?
 
I wasn't given this advice about the fin style coolers when I bought one and installed it, it was obvious that it trapped air and I couldn't bleed the system properly. I replaced it with the dual cooler bracket/single radiator from PSC and added a fan for when off-roading! I went to a local club event and the owner of redneck ram was there and asked why I had a cooler, I told him my reasoning, he went on and said that hydro assist systems run hot and that a cooler usually isn't necessary

Mine runs hot enough to feel a change in steering feel, and to also like out the overflow on the PSC reservoir cap vent line.
 
I've been running the redneck ram for almost 4 years, it would boil the fluid under hard use on the trails at first.
Added a big can style cooler and it helped alot, plus I had a small 6.5 inch helper fan blowing across it.
Never had any problems with it ever since.
 
How high do you fill your reservoir? Is it located by the battery or by the rad?

It's next to the radiator. Fluid level looks fine. It's got plenty of room left for expansion. Offroad Evolution installed it and filled it. It's fine until I get into areas where I am really working the steering, such as crawling through rocks.
 
It's next to the radiator. Fluid level looks fine. It's got plenty of room left for expansion. Offroad Evolution installed it and filled it. It's fine until I get into areas where I am really working the steering, such as crawling through rocks.

Same exact scenario as mine. on road & on trails - no issue. Working the steering/low speed is where I had issues.
Wonder if the reservoir installed by the rad has something to do with it. IDK, seems like a cooler can't hurt anything.

OP, don't let any of this cooler stuff scare you away from this system. It's well worth it and you'll be very happy with it. This is a side issue/very specific scenario where this cavitation occurs.
 
Top Bottom