Jeep Hydraulic Power Steering Fluid confusion.

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May 12, 2018
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Hi Guys.
According to some Jeep forums there seems to be some confusion around the power steering fluid used in the 2005-2010 Grand Cherokee. These are the systems used by the 5.7 and 3.0CRD. Namely the ones where the power steering pump also operates the cooling fan.

For years Chrysler have been saying that only MS-10838 hydraulic fluid is used and definately NOT ATF+4. It seems that the MS-10838 is becoming more difficult to source and now Chrysler are saying it is ok to use ATF+4!!!! What is going on here?

I noticed that Lubeguard steering fluid is suitable for many power steering systems requiring ATF specs but also MS-10838.

I suppose my question is this. With regard to power steering what is the difference between MS-10838 and ATF+4?

Thanks.
 
Hi Guys.
According to some Jeep forums there seems to be some confusion around the power steering fluid used in the 2005-2010 Grand Cherokee. These are the systems used by the 5.7 and 3.0CRD. Namely the ones where the power steering pump also operates the cooling fan.

For years Chrysler have been saying that only MS-10838 hydraulic fluid is used and definately NOT ATF+4. It seems that the MS-10838 is becoming more difficult to source and now Chrysler are saying it is ok to use ATF+4!!!! What is going on here?

I noticed that Lubeguard steering fluid is suitable for many power steering systems requiring ATF specs but also MS-10838.

I suppose my question is this. With regard to power steering what is the difference between MS-10838 and ATF+4?

Thanks.
Obtain a sample of each fluid and then send off the sample to Blackstone for a basic analysis and post the results here.
 
Hi
Thanks for the feedback. Postage to Blackstone may be excessive and possibly not allowed by Air.

I will try find a spec sheet for the Oils.
 
Hi Guys.
According to some Jeep forums there seems to be some confusion around the power steering fluid used in the 2005-2010 Grand Cherokee. These are the systems used by the 5.7 and 3.0CRD. Namely the ones where the power steering pump also operates the cooling fan.

For years Chrysler have been saying that only MS-10838 hydraulic fluid is used and definately NOT ATF+4. It seems that the MS-10838 is becoming more difficult to source and now Chrysler are saying it is ok to use ATF+4!!!! What is going on here?

I noticed that Lubeguard steering fluid is suitable for many power steering systems requiring ATF specs but also MS-10838.

I suppose my question is this. With regard to power steering what is the difference between MS-10838 and ATF+4?

Thanks.
Here are the results from the Nissan OEM EPSF which I assume would be similar:

Boron - 50 ppm
Calcium - 5 ppm
Sodium - 3 ppm
Magnesium - 970 ppm
Phosphorus - 650 ppm
Zinc - 700 ppm
Viscosity - 7.0 cSt@100C

Lots of AW and friction modification components.

The Nissan system uses about 6 oz. of fluid.
 
Last edited:
Here are the results from the Nissan OEM EPSF which I assume would be similar:

Boron - 50 ppm
Calcium - 5 ppm
Sodium - 3 ppm
Magnesium - 970 ppm
Phosphorus - 650 ppm
Zinc - 700 ppm
Viscosity - 7.0 cSt@100C

Lots of AW and friction modification components.

The Nissan system uses about 6 oz. of fluid.
Hi
Thank you for the help.

I have done a search of the forum but can't find a virgin uoa of atf+4. I did find mercedes mb236.12 which is for nag1 same as atf+4.

Boron - 134 ppm
Calcium - 579 ppm
Sodium - 0 ppm
Magnesium - 0 ppm
Phosphorus - 696 ppm
Zinc - 0 ppm
Viscosity - 6.27cSt@100c

I am very much a layman with these things but it seems that the PSF and Transmission fluid are like chalk and cheese.

Would you agree?
 
...For years Chrysler have been saying that only MS-10838 hydraulic fluid is used and definately NOT ATF+4. It seems that the MS-10838 is becoming more difficult to source and now Chrysler are saying it is ok to use ATF+4!!!! What is going on here?...
Is here an official statement or TSB from Chrysler that says one can use ATF+4 to replace the MS-10838 hydraulic fluid, or is this simply some internet chatter?
 
Hi MK
It is what people are allegedly being told by Jeep dealers when trying to purchase the MS-10838. I have no reason to doubt what they say, but yes i suppose it could be called internet forum chatter.

I thought i would ask people who know what they are talking about when it comes to fluids just what the difference is.
 
Hi MK
It is what people are allegedly being told by Jeep dealers when trying to purchase the MS-10838. I have no reason to doubt what they say, but yes i suppose it could be called internet forum chatter.

I thought i would ask people who know what they are talking about when it comes to fluids just what the difference is.
You could get a Blackstone VOA done on both the MS-10838 and the ATF+4 so that we could see the general chemical signature differences and viscosity and compare the two, but it won't tell us if there is special chemistry in either. A forensic's analysis will do that but it is expensive.

I do obtain fluids and do forensic's analyses on contract for various organizations, but I don't sample new or exotic fluids every day and report them on BITOG.
 
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