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Power Steering Fluid Question - Mixing red and green?

496 Views 14 Replies 4 Participants Last post by  jeep_lover_brazil
Greetings :)

New Jeep owner here from the UK but currently living in Brazil.

I recently bought a a 2011 WK2 Limited(3.6 Pentastar) with fairly low miles of 60,000 so I wanted to replace all the fluids and noticed that for power steering fluid the manual calls for MS-1165 or Fuchs EG ZH 3044 or Pentosin CHF 11s which are green.

My problem is there is red dirty fluid already in the steering system so I believe someone at some point replaced with ATF or where I am in Brazil they possibly initially filled with the Mopar ATF+4(MS 9602) as the climate is warmer here as the green MS 1165 spec fluid is better for cold weather apparently.

I have read it could be bad to mix the colors 🤷‍♂️?

Either way I would love anybody's recommendation for what to do.

regards ;)
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What does the reservoir cap say?

It's very bad to mix fluids if you have the electro-hydraulic power steering system, which takes only green fluid, but that was not standard equipment on early WK2s.
Hey, cap says "Use approved Power Steering fluid" (seriously - where do they find these industrial designers lol) manual is in Portugueses but definitely states the 3.6 engine needs the MS-1165/FUCHS EG ZH 3044/CHF 11S green fluid so I can only assume it has the electro-hydraulic system.

I don't want to have a failure deep in Brazil driving so I think I am going to have to completely flush out and replace with green fluid with engine off, drive for a bit then totally flush a second time as the additives in the red and green fluids do not mix well, heck I may even need a total third flush lol.
The owners manual says the 2011 V6 has the electro-hydraulic power steering system. And that it needs MOPAR Hydraulic Fluid or equivalent meeting MS-1165, such as Fuchs EG ZH 3044 or Pentosin CHF 11s.

The V8 has the belt driven pump which uses ATF.

Somewhere along the way the fluids got switched.

You should not mix fluids. I don't know if flushing out the ATF and replacing with the green stuff does more harm than good. The service manual references MS-11655. Perhaps a typo.
I know this is obviously somewhat frustrating, as leaving it may be causing damage and also flushing it may cause damage only thing I can think of that may be the potentially least damaging option of all is to flush with a universal hydraulic fluid that will do the job of lubricating the system but not react with whatever the hell is in there. :unsure:
This says that, although compatible, mixing should be avoided and that a complete oil change is recomended whan converting.

Looks like its been talked about on bobistheoilguy forums since the mid 90s. Seem that ATF can be hard on the rack seals and that its low temperature capability leaves a lot to be desired. MS-11655 works well at very low temperatures and is better for seals at that temperature. Doesn't seem to be an emergency do not drive situation, especially in warm weather, but MS-11655 is better for electrical/electronic power steering.

For example

Thanks for the info, I think I'm going to attempt the complete flush (with the engine off and front tyres off the ground is best IMO) as the vast majority of current oil will be replaced quite quickly hopefully not giving a very long chemical reaction time between red and green additives(I hope lol). Then there will be the residual old oil coating that will mix in with the new green fluid which ideally I would have to do a second time. 🤞
I have the green stuff Pentosin CHF-11S in my Mercedes power steering and hydraulic suspension “ABC” system. I also have it in my audi power steering (Volkswagen-Audi branded fluid). It is a hydraulic oil with “less flammable” properties than other hydraulic oils. Very spendy stuff.

You will need to buy more than the official capacity for when you do a flush. Maybe you can tap the line coming back to the steering fluid reservoir and dump that while refilling the Rez with the clean supply, while turning the steering wheel lock to lock.
I have 3 litres arriving today hopefully, and yes you are right I think the top line in the reservoir is the return line so I will attach a tube to this to catch the old/red/wrong fluid and I may even atttach the supply line from the reservoir to the whole 3 so I don't have to constantly top up the reservoir. Engine will be off but should ignition be on?
Any idea what the capacity is?
Quick update, I think there may be an error in the manual as it says the 3.6 needs MS-1165 or Fuchs EG ZH 3044 or Pentosin CHF 11s but it looks like I do not have (AFAICT) an electric hydraulic pump??? So the red fluid which I thought was wrong looks to be correct after all. This is cool as I do not have to worry about mixing red and green fluids hopefully. (Damn that Jeep clown manual - errors are costing me a fortune) 😅

My engine bay:

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There are a few differences between so called domestic and export models. I didn't think early 2011s got the electric pumps, it was a running change, but its been awhile. Could be one of those planned changes that did not get implemented right away due to parts shortages.
Cheers for all the info ColdCase, you really are super helpful on here 👍

Its a bummer as I already bought 6 quarts of green fluid lol.

But now I don't trust anything written in the manual so I need to check if the stated gear fluid for the 3.6(with Quadra-trac II) front+rear differentials is correctly stated as 75w-140.

Incorrect info in the manual is seriously lame 🤡
The factory service manual describes both pumps, but don't differentiate the engine.

The service manual specifies Mopar® Gear and Axle Lubricant 75W-85 for all axles (GL-5 Synthetic). 1 Liter more or less front, 1 to 1.5 Liters for the rear depending on axle. A modifier is needed for QD rear diffs. This is consistent with the 2012 owner's manual and the 2011 manual rev 7. Rev 4 had higher weight oil that varies with engine/axle. Perhaps they changed from 140w to 85w for fuel mileage or perhaps to reduce confusion? When you reference owner's manuals, there are revisions. The 2011 manual has 8 revisions I think.

MOPAR® ATF+4 for transmissions and transfer case.
The way I read things in an english version manual was the 5.7 was explicitly stated to use 75w-90 or 75w-85 (depending on ELSD) so I thought this meant that all other engine models including my 3.6 would need 75w-140 for both the front and rear differentials.

My Brazilian manual which came with the car says the same thing in Portuguese. I don't know which revision the manual is as it is missing its first pages.

If anybody has had a bad experience using 75w-140 on an early wk2 I would love to know ;)

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