Cat Hydraulic oil.

[vtfireman85]

I need to add hydraulic fluid to my skid steer, a  2004 236B, last time I changed it I had gone to Milton and got oil, I don’t remember what specifically it was, and I don’t have a day to go get more from Milton. I have lots of Hytran, and I have AW-68. I’ve been searching for the manual, but I am worried it got misplaced when I moved houses several years ago. 
what is safe to use? 
@Cattech

@DirtBoyz07

[Cattech]

The Cat specified lube is 10 wt. Hyd unless over 105f ambient. IIRC, the Cat Advanced 10 HDO is supposed to flow like an ISO 32 but has the sheer/load characteristics of an ISO 68. It also is rated for a 6000+ hour change cycle with regular oil sampling.

95% certain the Operation & Maintenance Manual lists Cat Multipurpose Tractor Oil (MTO) as an acceptable substitute for Adv 10 with a 1000 hour change cycle. MTO is Cat's version of Hytran.

[vtfireman85]

24 minutes ago, Cattech said:

95% certain the Operation & Maintenance Manual lists Cat Multipurpose Tractor Oil (MTO) as an acceptable substitute for Adv 10 with a 1000 hour change cycle. MTO is Cat's version of Hytran.

So if I understand you correctly, as long as I change on regular intervals HyTran would work with what’s in it? 

[mike newman]

...had a hydraulic pump failure in the (my )   Caterpillar   930   wheel loader....this at very modest hours...and despite using the Ghee Whiz Caterpillar branded oil...

...new pump, and regular BP oil of the correct grade....never had another problem...

I reckon that those ''branded oils '' that some manufacturers advocate....are only more expensive because the container has a lot more art work thereon......

...the truly dedicated CAT owners.....the dyed in the wool believers..... the blokes that prior going to sleep, read a few select passages from their  operators manuals...its like an aphrodisiac to them...and they would be appalled at the ''non believers ''  who brought regular lubricants....

Had a Mate with a D6C, who ran the prescribed 30 wt oil in one final drive and used a totally different product , from the Clarke engineered earth moving equipment...in t'other side...it was very black looking, smelled odd., far heavier viscosity..(we had it in a 55B  Loader)....and it functioned ,trouble free for the life of his machine, whist he owned it.....

Mike

[just Dave]

12 minutes ago, mike newman said:

...had a hydraulic pump failure in the (my )   Caterpillar   930   wheel loader....this at very modest hours...and despite using the Ghee Whiz Caterpillar branded oil...

...new pump, and regular BP oil of the correct grade....never had another problem...

I reckon that those ''branded oils '' that some manufacturers advocate....are only more expensive because the container has a lot more art work thereon......

...the truly dedicated CAT owners.....the dyed in the wool believers..... the blokes that prior going to sleep, read a few select passages from their  operators manuals...its like an aphrodisiac to them...and they would be appalled at the ''non believers ''  who brought regular lubricants....

Had a Mate with a D6C, who ran the prescribed 30 wt oil in one final drive and used a totally different product , from the Clarke engineered earth moving equipment...in t'other side...it was very black looking, smelled odd., far heavier viscosity..(we had it in a 55B  Loader)....and it functioned ,trouble free for the life of his machine, whist he owned it.....

Mike

Hi Mike .  Nobody knows like you, the voice of experience. I hope you all are feeling well!

[mjcolemn]

85505 Napa T0-4 10 weight. I have put Hytran in them at the customers request so everything is using the same oil, no issues yet.

[vtfireman85]

52 minutes ago, mjcolemn said:

85505 Napa T0-4 10 weight. I have put Hytran in them at the customers request so everything is using the same oil, no issues yet.

I’ve had TO-4 before, I don’t know what took it. 

[Dirt_Floor_Poor]

The last two Cat loaders we had, we put Deere Hy-Guard in them. We had a 277 and 279. They are both gone now. 

[supermechanic]

 I run cheap oil in machines that rarely get used. Changing out for water contamination hurts a lot less at 12 bucks a gallon vs 40.

 If you are putting 1000 hours a year or more on the machine, pony up for the fancy stuff.

 Oil analysis every 250 hours will tell if the machine is in harmony with your choice of fluid.

[Cattech]

12 hours ago, vtfireman85 said:

So if I understand you correctly, as long as I change on regular intervals HyTran would work with what’s in it? 

I never got a chance to check my memory to the specs while at work last night, but yes, Hytran, especially the newest latest version should be fine.

[yellowrosefarm]

10 hours ago, Dirt_Floor_Poor said:

The last two Cat loaders we had, we put Deere Hy-Guard in them. We had a 277 and 279. They are both gone now. 

We use Hyguard in our 259D and 914M at work.

[1586 Jeff]

PLEASE do not put your Uncle MTO into your skidsteer!!!

Would someone please make sure that Sethro understands the difference between Caterpillar MTO and his Uncle MTO?

Thank you!

[Pukeko]

I use Chevron "TorqForce" 10 W in my Cat 257B2 Skid steer.It has the specs for Cat and is 2/3 the price . Especially when you blow a hose or bust a line and its pissing on the ground. Exxon /Mobil makes the oil for Cat since 1987.Prior to that it was Chevron I think? Some "dyed-in - the - wool" Cat guys think Cat makes their own oil, but it is made  to their spec by outsiders. Same as JD owners  buying JD branded oil,batteries ,tools etc at twice the price .Nothing wrong with it  if you insist on paying more I guess!

[Gearclash]

Before using AW oils, check the anti wear additive levels.  Oil guy I spoke with once said AW oils tend to be 900-1000 PPM of ZDDP and top shelf hydraulic oils were more like 1200 PPM.  A skidsteer is not a place for inferior hydraulic oils; I would recommend a premium hydraulic oil for them. AW is more mid level as I understand it. 

[Binderoid]

22 hours ago, mike newman said:

...had a hydraulic pump failure in the (my )   Caterpillar   930   wheel loader....this at very modest hours...and despite using the Ghee Whiz Caterpillar branded oil...

...new pump, and regular BP oil of the correct grade....never had another problem...

I reckon that those ''branded oils '' that some manufacturers advocate....are only more expensive because the container has a lot more art work thereon......

...the truly dedicated CAT owners.....the dyed in the wool believers..... the blokes that prior going to sleep, read a few select passages from their  operators manuals...its like an aphrodisiac to them...and they would be appalled at the ''non believers ''  who brought regular lubricants....

Had a Mate with a D6C, who ran the prescribed 30 wt oil in one final drive and used a totally different product , from the Clarke engineered earth moving equipment...in t'other side...it was very black looking, smelled odd., far heavier viscosity..(we had it in a 55B  Loader)....and it functioned ,trouble free for the life of his machine, whist he owned it.....

Mike

My dad bought our D6C new in '76... ran it for 15 years  before we learned that we weren't supposed to be adding 90W to the finals. Discovered this  error when some wire got wound around  the sprocket and took out the seal. Other than that, no troubles. 

The whole machine was either  10W or 30W . 

[Pukeko]

I worked for a guy back in late 70,s for several winters in the oil fields, and he had 6,s,7,s and 8K,s .Everything used Mobil XD 30 weight in engine ,trans ,finals, trans(stick and powershift),hydraulics .All with no problem. It simplified maintenance with the 40 odd cats he ran.At the low temps we worked in northern Alberta ,sometimes down to minus 55 C, the lighter viscosity helped. Note ,back then ,no fancy cabs,just a ROPS with lots of tarp.

[Cattech]

Here's the chart for a B series Cat SSL.

 

More Cat Hydraulic oil information.

Hydraulic Systems

Refer to the “Lubricant Information” section in the latest revision of the Special Publication, SEBU6250  , "Caterpillar Machine Fluids Recommendations" for detailed information. This manual may be found on the web at Safety.Cat.com.

The following are the preferred oils for use in most Cat machine hydraulic systems:

• Cat HYDO Advanced 10 SAE 10W
• Cat HYDO Advanced 30 SAE 30W
• Cat BIO HYDO Advanced

Cat HYDO Advanced oils allow 6000 hours or higher oil drain intervals for most applications. S·O·S Services oil analysis is recommended when the oil drain interval is increased to 6000 hours or higher. In comparison, non-Cat commercial hydraulic oils (second choice oils) allow 2000 hours oil drain interval. Itis recommended to followthe maintenance interval schedule for oil filter changes and for oil sampling that is stated in the Operation and Maintenance Manual for your particular machine. Consult your Cat dealer for details. When switching to Cat HYDO Advanced fluids, cross contamination with the previous oil should be kept to less than 10%.

Second choice oils are listed below.

Cat MTO

• Cat DEO
• Cat DEO-ULS
• Cat TDTO
• Cat TDTO Cold Weather
• Cat TDTO-TMS
• Cat DEO-ULS SYN
• Cat DEO SYN
• Cat DEO-ULS Cold Weather

Note: Oil drain intervals of the oils listed above are less than those of Cat HYDO Advanced oils. The oil drain interval of these oils is typically 2000 hours and up to a maximum of 4000 hours. An exception is Cat TDTO Cold Weather oil which allows 6000 hours or higher oil drain interval. S·O·S Services oil analysis is required when the oils listed above are used in Cat hydraulic system components and hydrostatic transmissions.

Table 2

Lubricant Viscosities for Ambient Temperatures
Compartment or System	Oil Type and Performance Requirements	Oil Viscosities	°C		°F
			Min	Max	Min	Max
Hydraulic System	CatHYDO Advanced 10 Cat TDTO	SAE 10W	−20	40	−4	104
	Cat HYDO Advanced 30 Cat TDTO	SAE 30	10	50	50	122
	Cat BIO HYDO Advanced	"ISO 46" Multi-Grade	−30	50	−22	122
	Cat MTO Cat DEO-ULS Cat DEO	SAE10W-30	−20	40	−4	104
	Cat DEO-ULS Cat DEO	SAE15W-40	−15	50	5	122
	Cat TDTO-TMS	Multi-Grade	−15	50	5	122
	Cat DEO-ULS SYN Cat DEO SYN	SAE 5W-40	−30	40	−22	104
	Cat DEO-ULS Cold Weather	SAE0W-40	−40	40	−40	104
	Cat TDTO Cold Weather	SAE 0W-20	−40	40	−40	104

[vtfireman85]

54 minutes ago, Cattech said:

Here's the chart for a B series Cat SSL.

 

More Cat Hydraulic oil information.

Hydraulic Systems

Refer to the “Lubricant Information” section in the latest revision of the Special Publication, SEBU6250  , "Caterpillar Machine Fluids Recommendations" for detailed information. This manual may be found on the web at Safety.Cat.com.

The following are the preferred oils for use in most Cat machine hydraulic systems:

• Cat HYDO Advanced 10 SAE 10W
• Cat HYDO Advanced 30 SAE 30W
• Cat BIO HYDO Advanced

Cat HYDO Advanced oils allow 6000 hours or higher oil drain intervals for most applications. S·O·S Services oil analysis is recommended when the oil drain interval is increased to 6000 hours or higher. In comparison, non-Cat commercial hydraulic oils (second choice oils) allow 2000 hours oil drain interval. Itis recommended to followthe maintenance interval schedule for oil filter changes and for oil sampling that is stated in the Operation and Maintenance Manual for your particular machine. Consult your Cat dealer for details. When switching to Cat HYDO Advanced fluids, cross contamination with the previous oil should be kept to less than 10%.

Second choice oils are listed below.

Cat MTO

• Cat DEO
• Cat DEO-ULS
• Cat TDTO
• Cat TDTO Cold Weather
• Cat TDTO-TMS
• Cat DEO-ULS SYN
• Cat DEO SYN
• Cat DEO-ULS Cold Weather

Note: Oil drain intervals of the oils listed above are less than those of Cat HYDO Advanced oils. The oil drain interval of these oils is typically 2000 hours and up to a maximum of 4000 hours. An exception is Cat TDTO Cold Weather oil which allows 6000 hours or higher oil drain interval. S·O·S Services oil analysis is required when the oils listed above are used in Cat hydraulic system components and hydrostatic transmissions.

Table 2

Lubricant Viscosities for Ambient Temperatures
Compartment or System	Oil Type and Performance Requirements	Oil Viscosities	°C		°F
			Min	Max	Min	Max
Hydraulic System	CatHYDO Advanced 10 Cat TDTO	SAE 10W	−20	40	−4	104
	Cat HYDO Advanced 30 Cat TDTO	SAE 30	10	50	50	122
	Cat BIO HYDO Advanced	"ISO 46" Multi-Grade	−30	50	−22	122
	Cat MTO Cat DEO-ULS Cat DEO	SAE10W-30	−20	40	−4	104
	Cat DEO-ULS Cat DEO	SAE15W-40	−15	50	5	122
	Cat TDTO-TMS	Multi-Grade	−15	50	5	122
	Cat DEO-ULS SYN Cat DEO SYN	SAE 5W-40	−30	40	−22	104
	Cat DEO-ULS Cold Weather	SAE0W-40	−40	40	−40	104
	Cat TDTO Cold Weather	SAE 0W-20	−40	40	−40	104

Thank you! I ordered T-O4 today, it probably needs a gallon currently, I will give it a full change later this summer. As far as I know it had only had top up additions and no full change, but it wasn’t new when the PO bought it. It has around 1,100 hours on it. 

[DirtBoyz07]

I run the IH/ Viscosity Hy Tran in my Caterpillar D 6 N LGP dozer and it works great . It is the oil for just the hyd functions. I’m sure the IH / Viscosity oil would be just fine in a Cat skidloader as IH and Case IH run this in all the hydrostatic driven machines I’m guessing it would be just fine but the last thing is you don’t want to mess anything up on a hydrostatic transmission over the wrong oil 😳$$  I do run the Cat oil in my D 6 transmission just to be safe and with close to 11,000 hours on it now it’s been good and I only use Cat filters on on my cat stuff . We do stock the Viscosity 10 w hyd oil for the Cat skidloaders .

Danny

[Cattech]

On 5/14/2026 at 6:32 PM, vtfireman85 said:

Thank you! I ordered T-O4 today, it probably needs a gallon currently, I will give it a full change later this summer. As far as I know it had only had top up additions and no full change, but it wasn’t new when the PO bought it. It has around 1,100 hours on it. 

Being a "B" series 236, at least if it's an earlier HEN serial number, it probably has changed the hydraulic oil by itself (out the belly pan) a few times at 1100 hrs. Don't get me wrong, the HEN is a very good machine, but hose routing and retention under the cab was not their strong point. Some hose wrap and a bag of zip ties with a couple hours of effort under there is well worth it.

[vtfireman85]

6 hours ago, Cattech said:

Being a "B" series 236, at least if it's an earlier HEN serial number, it probably has changed the hydraulic oil by itself (out the belly pan) a few times at 1100 hrs. Don't get me wrong, the HEN is a very good machine, but hose routing and retention under the cab was not their strong point. Some hose wrap and a bag of zip ties with a couple hours of effort under there is well worth it.

I will check it out, but so far, no leakage issues.