Power Steering Moaning When Offroading

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LFD2037

LFD2037

TEXAS LEXUS!
10 Year
Joined
Oct 22, 2013
Threads
183
Messages
3,889
Location
Wax., TEXAS
@ the LSTJ a week ago my PS starting moaning. It would happen w/truck fully warmed up & only when going slow in rutted muddy trails or rock crawling. Once I'd get going or on the main road it'd stop. It never acted like it was stiffer/harder to steer. It's never done this before this trip. I decided it was probably due to old fluid. Got home & checked it & it was as black as black could be. I've been doing the easy method of flushing the fluid ie. suck the resevoir dry w/a syringe, fill back up w/ATF synthetic fluid, drive a day or 2 & repeat. I've sucked out & replaced a full qt. already & it's still very black, not pink @ all. I'm thinking the fluid has never been replaced. Will old fluid cause my symptoms?
 
LFD2037 said:
@ the LSTJ a week ago my PS starting moaning. It would happen w/truck fully warmed up & only when going slow in rutted muddy trails or rock crawling. Once I'd get going or on the main road it'd stop. It never acted like it was stiffer/harder to steer. It's never done this before this trip. I decided it was probably due to old fluid. Got home & checked it & it was as black as black could be. I've been doing the easy method of flushing the fluid ie. suck the resevoir dry w/a syringe, fill back up w/ATF synthetic fluid, drive a day or 2 & repeat. I've sucked out & replaced a full qt. already & it's still very black, not pink @ all. I'm thinking the fluid has never been replaced. Will old fluid cause my symptoms?
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Mine did that when I got it. I did the same thing and ended up having to change the pump. Been good as new since. If you do end up changing the pump, make sure you put the drive gear on at the same depth on the shaft as it came off. Otherwise you'll get some good gear wine noise. Lol and have to do it over. I measured with a set of calipers.
 
Mine was very black too, just as I was going to change the fluid, it started making a bit more noise, moaning might be the term or whining too. Then the return broke and I was able to flush it with anything we had on the trail. 10-40w to shock oil and GM LS fluid too.

You could disconnect the low pressure return line under the rez and start it up to dump it all out. Won't hurt it to run 'dry'. There is a good amount of fluid in there, the lil cooler plus old residue. You may never get it all out. Mine did sound a bit quieter with new fluid, but still there for the long haul, I believe.

Once you get it a bit cleaner, think about going with hydraulic fluid. I read a recent post here on Mud about more benefits and will be doing that next time soon.
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the main reason behind the moaning it's heat .. :D

so yes, old oil it's a part of the game, I would also check the paper clip cooler and if possible and upgrade, finally last but not least I will clean the mesh filter in to the reservoir and good wash / clean ..
 
Tapage said:
the main reason behind the moaning it's heat .. :D

so yes, old oil it's a part of the game, I would also check the paper clip cooler and if possible and upgrade, finally last but not least I will clean the mesh filter in to the reservoir and good wash / clean ..
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How do I get to the filter to clean it?
 
LFD2037 said:
How do I get to the filter to clean it?
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I un mount the filter and just wash it with some pressure .. from the bottom out.
 
Good chance your 3 low pressure lines are hard s a rock. Ought as well just pull and replace them while you are there. That will mean the majority of the fluid is replaced. Much better to do it at home instead of on the trail!
 
inkpot said:
Good chance your 3 low pressure lines are hard s a rock. Ought as well just pull and replace them while you are there. That will mean the majority of the fluid is replaced. Much better to do it at home instead of on the trail!
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Yeah, I need to do that. I'm halfass in the middle of Monstaliner the bottom half of my rig. When I finish that I'll do the low pressure lines and extend my breathers. Thanks.
 
No more PS fluid for me I have been running Mobile 1 hydraulic fluid in everything (cars, LC, Trucks, boat) for several years with not even a squeak. I do purge the reservoir several time once a year when I change my engine oil. Never boils over in the extreme AZ heat no matter how hard its pushed.
 
LandCruiserPhil said:
No more PS fluid for me I have been running Mobile 1 hydraulic fluid in everything (cars, LC, Trucks, boat) for several years with not even a squeak. I do purge the reservoir several time once a year when I change my engine oil. Never boils over in the extreme AZ heat no matter how hard its pushed.
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Same here. Been very happy with it.
http://www.amazon.com/gp/product/B009OXGFMG/?tag=ihco-20
31mcwRcn7JL.jpg
 
LandCruiserPhil said:
No more PS fluid for me I have been running Mobile 1 hydraulic fluid in everything (cars, LC, Trucks, boat) for several years with not even a squeak. I do purge the reservoir several time once a year when I change my engine oil. Never boils over in the extreme AZ heat no matter how hard its pushed.
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You and @NLXTACY are going to kill a bus load of nuns...
Seriously though, this is probably much better to use than ATF. The reason ATF is used is because it works just fine and its 1 less chemical to keep on hand at the plant.
 
LandCruiserPhil said:
No more PS fluid for me I have been running Mobile 1 hydraulic fluid in everything (cars, LC, Trucks, boat) for several years with not even a squeak. I do purge the reservoir several time once a year when I change my engine oil. Never boils over in the extreme AZ heat no matter how hard its pushed.
Click to expand...
Hows that stuff price wise? Mine started groaning today in the heat while in the rocks, and couple times it wouldn't budge without a slight rev if the engine. I'm going to upgrade the cooler to the finned model, new hoses and look into this oil a bit more. From past rigs, just seems like its too hot working the 37's
 
Psssh. You guys aren't stepping up if you're only using hydraulic oil.

I take roses and squeeze the essential oils out, filter with a centrifuge, and then process. Sure, it might end up costing $200/oz, but my truck is worth it.
 
Phildoh said:
Hows that stuff price wise? Mine started groaning today in the heat while in the rocks, and couple times it wouldn't budge without a slight rev if the engine. I'm going to upgrade the cooler to the finned model, new hoses and look into this oil a bit more. From past rigs, just seems like its too hot working the 37's
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About $25 gal
Several guys in AZ use it some with 37's
 
@Dragos80 I was waiting for someone to make that joke...

So the issue IS heat... @NLXTACY are you working on a system to monitor PS Temps yet? How about flow rates?

Basically what happens here is when you're not steering, the fluid recirculation in the vane pump. This causes the fluid to heat up. It eventually gets hot enough that it loses its lubricity and the pump might as well be running dry. This causes the moaning noise which is eventually followed by pump seizure.

Mr. T knows this is a problem, so he added a cooling loop in the system. It isn't the best way to do it, but it is the most economical and meets the performance requirements. After 20 years, and with old, broken down fluids, the system doesn't work so well and needs to be serviced and the hoses/Cooler need to be replaced.
 
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