Hydraulic fluid requirements

[saflyer]

My 2005 HR Ambassador manual says to use Dexron 3 transmission fluid in the leveling jacks hydraulic system. They continually upgrade these fluids over the years and are now up to Dexron 6, 3 is no longer available. Am I correct in thinking any Dexron with a number 3 or higher is OK for the hydraulic system? Also, an RV mechanic told me Mercon 5 is acceptable. Is that true?

Thanks

[Oregon04Windsor]

I recently went down this road.  Supposedly Dexron 6 is backwards compatible in transmission applications but not necessarily in hydraulic applications.  I didn't want to risk it and found that Dexron III is still readily available at most parts houses and tractor supply companies.  I found mine at Carquest for $80/5 gal of Dexron III/Mercon.  Walmart also carries Dexron III in gallon jugs.

 

Edited February 19, 2022 by Oregon04Windsor

[saflyer]

Thanks, I’ll look around. 
 

Interesting thing I noticed shopping for Dexron 3 on Amazon. Some of the brands just say Dex/Merc. Probably the latest spec but not sure. Might say in the fine print of the label what the number is.

Edited February 19, 2022 by saflyer

[vito.a]

I used Valvoline Dex/Merc.  

Valvoline DEX/MERC Automatic Transmission Fluid (ATF) 1 GA - Walmart.com

 Recommended for use in the following applications: MERCON*, DEXRON*-III, Ford M2C138-CJ and M2C166-H, Allison C-4 and TES-389, and Caterpillar TO-2.

• Formulated with premium base stocks and advanced additive technology to meet the challenging demands of automatic transmissions
• Engineered with a proprietary blend of base oils and advanced additives to provide better oil flow at low temperatures and greater film protection at higher temperatures
• Formulated with advanced additives to resist fluid breakdown and thickening at high temperatures
• Flows easily at low temperatures providing good cold-start shifting
• Greater friction stability to help maintain consistent shift performance
• Enhanced anti-shudder protection for smooth shifting and maximum power transfer
• Developed with anti-wear technology to help improve transmission durability
• Minimizes sludge and varnish deposits
• For use where DEXRON*-III or a MERCON* fluid is specified

If you want synthetic, then this will work:  Valvoline MaxLife Multi-Vehicle Full Synthetic Automatic Transmission Fluid (ATF) 1 GA - Walmart.com

[Calvin Morse]

I contacted "Bob The Oil Guy" Regarding Dextron III . He said to use Transynd TES-295 in my Nelson Hydraulic Reservoir to add or replace Dextron III. Its a TES-295 synthetic transmission fluid and It's fully compatible. You can also mix it with the existing Dextron III if just topping off.

[Fasthobie16]

What Vito says. Valvoline ATF Dex/Merc .Recommend for the Liberty trans  too 

Jim

2000 Dynasty/ 2004 Liberty Toad 

[saflyer]

Thanks, I’ll look around for the Valvoline Dex/Merc. I think I saw the same label on a Fram bottle. I’ll read the fine print.

[saflyer]

9 hours ago, saflyer said:

Thanks, I’ll look around for the Valvoline Dex/Merc. I think I saw the same label on a Fram bottle. I’ll read the fine print.

I found a qt. of Ace brand at Ace Hardware. Label says Dexron-3/Mercon. Going to use it.

[96 EVO]

On 2/19/2022 at 10:14 AM, Calvin Morse said:

I contacted "Bob The Oil Guy" Regarding Dextron III . He said to use Transynd TES-295 in my Nelson Hydraulic Reservoir to add or replace Dextron III. Its a TES-295 synthetic transmission fluid and It's fully compatible. You can also mix it with the existing Dextron III if just topping off.

That's pricey fluid to use in a simple hydraulic system!

[Calvin Morse]

I agree. I had extra. My understanding is that Monaco eventually went to synthetic.

[cbr046]

My hydraulic reservoir has an amber colored fluid, like fresh motor oil, but what's dripping out of the steering box is black.  Manual calls for "TF" but doesn't provide a specification. 

 I don't know of any TF / Trans Fluids  that are amber  . . . . did PO substitute Rotella for (ATF?) spec'd hydraulic fluid? 😲

I'll need to top off before the next trip.  What would the harm be to top off with Rotella vs ATF?

- bob

[96 EVO]

Amber could also be AW-46 hydraulic fluid.

Monaco had issues with filling the hydraulic system with the fluid stated in the owners manuals, that appears to have carried on for years!

Why they didn't insist the installer hang a tag stating the fluid he / she installed over the filler neck, is beyond me!! 

Edited November 14, 2023 by 96 EVO

[Frank McElroy]

11 hours ago, cbr046 said:

My hydraulic reservoir has an amber colored fluid, like fresh motor oil, but what's dripping out of the steering box is black.  Manual calls for "TF" but doesn't provide a specification. 

 I don't know of any TF / Trans Fluids  that are amber  . . . . did PO substitute Rotella for (ATF?) spec'd hydraulic fluid? 😲

I'll need to top off before the next trip.  What would the harm be to top off with Rotella vs ATF?

- bob

You likely have AW-46 hydraulic fluid - color is amber.  That's fine as long as you don't drive the coach in temps below about 20 degrees F.

Was black moly grease used when the steering gearbox was last greased?   Hopefully the gearbox was greased by hand and not by an air grease gun.  An air grease gun pressure can blow out the internal seal causing hydraulic fluid to leak out and mix with the grease.

[cbr046]

19 hours ago, Frank McElroy said:

You likely have AW-46 hydraulic fluid - color is amber.  That's fine as long as you don't drive the coach in temps below about 20 degrees F.

Was black moly grease used when the steering gearbox was last greased?   Hopefully the gearbox was greased by hand and not by an air grease gun.  An air grease gun pressure can blow out the internal seal causing hydraulic fluid to leak out and mix with the grease.

Grease?  I don't think there's a fitting on the steering box.  Manual says no and I don't recall one. 

OK, so AW46 is amber . . . . except when I opened the stuff I bought it's GREEN!  Tractor Supply, Mystic JT9 ISO46.  NONE of the other brands specifically called out AW46 and ALL the other brands had a host of manufacturer compliances.  I never knew buying hydraulic oil could be so hard.  Hopefully mixing it won't be a problem . . . . .

- bob