Hydraulic Oil Type for 743

[onepoket]

I know this has been covered in other places but there is still a lot of debate.

I got my machine recently and drained most of the fluids, for hydraulic oil I used Valvoline VV41 which is AW 32 hydraulic oil.

The ride has still been rough and change of direction jerky. I read somewhere that AW 32 was too thin for the older bobcat machines. The bobcat parts guy told me "any 30 weight oil". So, does this mean that AW 32 is too thin? ISO 32 = SAE 10 weight oil. If the bobcat guy meant SAE 30 that would be ISO 100. I tried to get clarification from him but he wasn't sure, and he basically was telling me to not buy bobcat oil because it was over priced so I didn't want to press him for an answer.

I have 15 gallons of Primex AW ISO 100 but I'm not sure wether to drain my ISO 32 or not. I literally just got done plowing 30 minutes ago and the machine ran OK, I'm not sure if it would run smoother with thicker oil or not. It does tend to moan and whine a bit and I know I still need to redo the lift cylinder seals, also there is another small leak near the valve or port block. Maybe its sucking air and that is making the controls rough.

Oh, BTW, I am in northwest NJ and we get some cold weather here unlike the rest of the state because of our elevation, not uncommon to get days below 0F if that factors in oil choice.

Thanks for any info! (let the debate begin)

 

[foton]

The book I believe says to use 10-30 engine oil, I do not have a 743 I have a 500 and I used universal tractor fluid and have had no issues , and that was my thinking in cold weather the hydros would work easier on cold start-up . Plus the utf has anti foaming agents.

 

[Tazza]

The book I believe says to use 10-30 engine oil, I do not have a 743 I have a 500 and I used universal tractor fluid and have had no issues , and that was my thinking in cold weather the hydros would work easier on cold start-up . Plus the utf has anti foaming agents.

I run 20w50, but i do live in an area that never gets below freezing.

 

[onepoket]

I run 20w50, but i do live in an area that never gets below freezing.

I wanted to come back and update this. I have a friend in CA and apparently he works for Bobcat, so I asked him to ask the mechanics there what ISO they suggest for my machine. I am currently running ISO 32. The bobcat guys in CA said I should run ISO 46, my guess is, that is the rating on the bobcat fluid that you pay an arm and a leg for. I figure when it gets warm I will replace my oil with what they suggest. I have some leaks to fix and will most likely drain it all anyway, maybe use the iso 100 or 32 i have on hand for the chain case when I drain that. Hope this info helps someone else, there are so many conflicting posts on the internet about what oil to use and it makes it even more confusing with some people using SAE and some ISO.

 

[HanSolo]

I have a 743 and use non-detergent 30W motor oil. That is pretty much the same as the Bobcat hydraulic fluid at $75 for 5 gal. I get mine at tractor supply for about $45 for 5 gal.

 

[tinknal]

I have a 743 and use non-detergent 30W motor oil. That is pretty much the same as the Bobcat hydraulic fluid at $75 for 5 gal. I get mine at tractor supply for about $45 for 5 gal.

I just bought a 743. The guy I got it from told me that the Bobcat dealership that he bought it from told him to use 10W30. This is in Minnesota where it gets bitter cold. He used it in the winter cutting firewood and reported no issues.

 

[foton]

I just bought a 743. The guy I got it from told me that the Bobcat dealership that he bought it from told him to use 10W30. This is in Minnesota where it gets bitter cold. He used it in the winter cutting firewood and reported no issues.

maybe in a heated barn ,at below freezing temps. out in the open maybe not. the 743 is cold natured as the glow plugs go. the battery won't work as well .there are quite a few things that will work against you at below 0 and colder. a battery blanket a block heater would be on my wish list.

 

[tinknal]

maybe in a heated barn ,at below freezing temps. out in the open maybe not. the 743 is cold natured as the glow plugs go. the battery won't work as well .there are quite a few things that will work against you at below 0 and colder. a battery blanket a block heater would be on my wish list.

Guy I got it from claimed no starting issues al long as it gets a good 90 seconds of glowplug. It has a block heater and It will be stored in an unheated shed.

 

[reaperman]

Guy I got it from claimed no starting issues al long as it gets a good 90 seconds of glowplug. It has a block heater and It will be stored in an unheated shed.

I'm a bit confused, a battery blanket and glow plugs are referring to the engine oil. Your question is about the 10w-30 used as hydraulic oil in older machines. Yes, 10w-30 was and is still used my many machines of that era even in the cold. I too, live in Minn and my 753 is stored in a unheated shed and is used for snow plowing etc in the winter. About two years ago I was going to make the switch to the new bobcat hyd fluid. I went to the dealer to purchase the fluid and the mechanic there said to me. Unless my hydraulics were contaminated with water leave it alone, it would be hard to drain out the old fluid and would most likely break a fitting trying. Someday when you blow a hose, then make the switch.

 

[onepoket]

I'm a bit confused, a battery blanket and glow plugs are referring to the engine oil. Your question is about the 10w-30 used as hydraulic oil in older machines. Yes, 10w-30 was and is still used my many machines of that era even in the cold. I too, live in Minn and my 753 is stored in a unheated shed and is used for snow plowing etc in the winter. About two years ago I was going to make the switch to the new bobcat hyd fluid. I went to the dealer to purchase the fluid and the mechanic there said to me. Unless my hydraulics were contaminated with water leave it alone, it would be hard to drain out the old fluid and would most likely break a fitting trying. Someday when you blow a hose, then make the switch.

I should have responded earlier to this. I have a friend in California who works at bobcat there. I had him ask the techs what oil I should be running in my 743 they told him iso 46 was the correct viscosity.

 

[[email protected]]

I should have responded earlier to this. I have a friend in California who works at bobcat there. I had him ask the techs what oil I should be running in my 743 they told him iso 46 was the correct viscosity.

i use the one NAPA has in 5 gallon buckets, i think its AW32 but i can confirm that

 

[gyzmo]

i use the one NAPA has in 5 gallon buckets, i think its AW32 but i can confirm that

I had a 743, now I have a 753. Every time I ask the local Bobcat dealer, he says just use the same as you put in the engine. So standard Diesel engine oil they get. No problems at all And I live in an area that gets below freezing and up to 40 degrees centigrade

 

[Tazza]

I had a 743, now I have a 753. Every time I ask the local Bobcat dealer, he says just use the same as you put in the engine. So standard Diesel engine oil they get. No problems at all And I live in an area that gets below freezing and up to 40 degrees centigrade

That's what my dealer told me years ago, he was there for when the 743s first came out. They used the same oil in the engine as hydraulics, before bobcat started selling their own fluid.
I run 15W40 in my engine, i run 20W50 in my hydraulics because i got a good deal on it. Now the next deal rolled around for 15W40 (a little over 2 bucks a litre), next oil change, is't being changed to that

 

[mikko]

That's what my dealer told me years ago, he was there for when the 743s first came out. They used the same oil in the engine as hydraulics, before bobcat started selling their own fluid.
I run 15W40 in my engine, i run 20W50 in my hydraulics because i got a good deal on it. Now the next deal rolled around for 15W40 (a little over 2 bucks a litre), next oil change, is't being changed to that

vane pump and that`s why you should use a motor oil in your hydraulics because better lubrication...

 

[willett]

I have been running 46 in mine and it seems to.do alright. It gets pretty chilly in my neck of the woods.

 

[dcrobinson]

I'm a bit confused, a battery blanket and glow plugs are referring to the engine oil. Your question is about the 10w-30 used as hydraulic oil in older machines. Yes, 10w-30 was and is still used my many machines of that era even in the cold. I too, live in Minn and my 753 is stored in a unheated shed and is used for snow plowing etc in the winter. About two years ago I was going to make the switch to the new bobcat hyd fluid. I went to the dealer to purchase the fluid and the mechanic there said to me. Unless my hydraulics were contaminated with water leave it alone, it would be hard to drain out the old fluid and would most likely break a fitting trying. Someday when you blow a hose, then make the switch.

Hello
Brand new owner of my 80s bobcat 743. Question: Where do you check the transmission fluid?

 

[brdgbldr]

Hello
Brand new owner of my 80s bobcat 743. Question: Where do you check the transmission fluid?

There is a plug on the front of the chain case. If you can touch oil with your finger I the hole to the first knuckle, the oil is high enough.

Since you just got this machine, you should pump some of the oil out to check if it has water in it.

You can also remove the front inspection plate that is on the top of the chain case. However, you will probably have to replace the gasket if you do that.

 

[laurencen]

on our 2 743s we run 10-30 motor oil in hydraulics, have done for years I believe service manual also says motor oil, it gets to -40C here during winter, never a issue