743 new owner with questions

[Rynowb]

I recently purchased a 743 with 2.2k hours and I'm having some issues. First and foremost it's leaking hydraulic fluid like crazy after using it for a few hours and for the life of me I can't figure out where it's coming from.... I lifted the cab and searched and as it sits not running it appears to not be leaking from anywhere I can see but after running it for an hour I parked it in my shop and it has about a one quart puddle under it. I don't know where it's coming from and it's driving me crazy.
Second issue is, I ordered all new filters for it but I'm getting mixed results on searches for what engine oil I should use and which hydraulic fluid as well. If it helps I live in Washington state and we see about 10-20 days a year under freezing. I own a couple diesel trucks and run 15-40 in them without issue.
The few hours I've ran it I've been very happy with it's performance but it's quickly turning into another useless tool for me. Any help would be appreciated!!!!

 

[Junkers]

For the oil I put 10w30 in both the hydro and engine to keep it simple. For the oil leak, is everything under the cab soaked in oil? If so pressurewash/decrease it and run it for a while then double check. If it's all dry under the cab. Open up the doors on the blower shroud and check the oil cooler.

 

[Chris 8603]

I run 10w30 in my engine, but run 20w in my hydraulics. What good for your trucks should be just fine for your machine too. Mine just seems to like 20 vs 30 hydraulic fluid better. As far as the leak, do like firefighter said and if you still can't pinpoint where it's coming from, get you some uv dye and add it to your hydro tank. Run it though all the motions, even aux for a few minutes hit it with a light. Then you can see the glow and hopefully find the culprit!!! Good luck

There's no such thing as a useless skidsteer!!

 

[mrbb]

I agree, the best way to find the leak is to first clean the machine, so you can spot new oil leaking
as if not, its extremely hard to find leaks unless you see it spraying out!

or you can do as others have and add some Dye to the system to look for where it first shows up leaking/area at!(just make sure its the right type of dye and have the light and glasses to see it afterwards), do a search here, there was just a another post about this stuff and what all to use!

I however, am NOT a fan of using a pressure washer, senn to many times it push water past seals ind or into places it sghouldn;t be, and
all the more so on older machines ,
better to just scrap heavy stuff off first with something, vacuum up as much dirt and debris as possible and then

just use some good de greaser, let it soak and have time to work, then use a basic garden hose and nozzle to rinse it off,
to speed drying , you can use a leave blower, too!

as for what OIL to use,
I would think based on year of machine, it was designed to use, either 10w-30 or pure 30 weight diesel oil!
A simple call to your local bobcat dealer should get you exact what fluids to use where, if you don;'t have a owners manual or service manual!
Hydraulic fluid, I gather is the Bobcat based stuff, as seems many Bobcats all state to ONLY use that in them??
I knwo soem don't, but but I do believe it is called for there bbrand ONLY, so take that as you wish! no bash here!

 

[Chris 8603]

This is the type dye you will need. Also you will need a good uv light, and the uv glass. You don't have to have this brand specifically, just this type. Add 1oz per 1 gallon of fluid. Equipment manufacturers don't make there own oil, they have it made to there specs. Any oil that meets api specs (moat name brands) will work just fine. Everybody has there favorite go to fluid. As long as you use the proper weight for your usage (temp)you will fine.

 

[jp8775]

I bought a 843 for $6500 to turn around and sell, runs great and is a monster, but it too leaks hydraulic oil when running its around the valve and leaks when just idling but its not the valve that I can find. I too will use dye to find the leak but I also have two 743's as well to get ready to sell. I think dye is the only way to find the leak unless its obvious. Please let us know if you find the leak and how!

 

[Chris 8603]

I bought a 843 for $6500 to turn around and sell, runs great and is a monster, but it too leaks hydraulic oil when running its around the valve and leaks when just idling but its not the valve that I can find. I too will use dye to find the leak but I also have two 743's as well to get ready to sell. I think dye is the only way to find the leak unless its obvious. Please let us know if you find the leak and how!

When I bought my 743 it had been sitting for 5-6 years because of a blown hose and had been leaking at the valves. Thinking at first it was the valves leaking they never took time to repair it. Then a few years later that hose blew. He couldn't find anyone that would replace the hose and not wanting to take it to bobcat, he parked it. It sat for all those years when I bought it for a song. NOW let me tell you that hose was something to change!!! I had to make a wrench to get it off and my then 10yr son was the only 1 of 4 of us that could get 2 hands in there to remove it or install it. I don't know how bobcat does it except by removing the pumps. I don't remember what the other part was it connected to, but it made it look like the valve was leaking. After the repair the valves weren't leaking after all. It's a short hose about 16" long that makes a u down from 1 to the other. Look close at it when you are searching for your leak.

 

[harold duren]

Back in 1985 when I bought my 743. I asked Bobcat what oil to use for drive box and they told me to use 10W40. Been working good all these years.
Does anyone have any pointers for changing starter?
Thanks

 

[GeorgeG]

The hose that feeds the control valve is a common failure on these older machines. There's an access door behind the right rear wheel that allows access. As for oil choice, today's 15w40 name brand diesel oils are all good. Do not use engine oil in your Bobcat hydraulics. Danfoss Sauer hydrostatic have specific antiwear requirements. Either use Bobcat brand or have your lubricant supplier cross reference to a good hydrostatic fluid. I use Cenex ISO46 hydrostatic fluid.

 

[Chris 8603]

What machine are you referring to that has the access door. Just curious

The hose that feeds the control valve is a common failure on these older machines. There's an access door behind the right rear wheel that allows access. As for oil choice, today's 15w40 name brand diesel oils are all good. Do not use engine oil in your Bobcat hydraulics. Danfoss Sauer hydrostatic have specific antiwear requirements. Either use Bobcat brand or have your lubricant supplier cross reference to a good hydrostatic fluid. I use Cenex ISO46 hydrostatic fluid.

 

[mdstihl]

The hose that feeds the control valve is a common failure on these older machines. There's an access door behind the right rear wheel that allows access. As for oil choice, today's 15w40 name brand diesel oils are all good. Do not use engine oil in your Bobcat hydraulics. Danfoss Sauer hydrostatic have specific antiwear requirements. Either use Bobcat brand or have your lubricant supplier cross reference to a good hydrostatic fluid. I use Cenex ISO46 hydrostatic fluid.

There's no access door on the 743.
The OP can google "nightmare hose bobcat" and it should lead to the thread here. My post tells how I tackled it. Halfway thru I was thinking about torching an access door tho. Lol

 

[Chris 8603]

That's why is was asking GeorgeG which machine he was referring to. I've done 4 of those since I first did mine is was just curious what he was talking about. Because like you said there is no door though the chain case on a 743 and the valve sits between the tires not in the behind the rear. I think he meant some other brand. I've not seen a access door though the chain case on any bobcat. May be wrong ????

There's no access door on the 743.
The OP can google "nightmare hose bobcat" and it should lead to the thread here. My post tells how I tackled it. Halfway thru I was thinking about torching an access door tho. Lol

 

[mdstihl]

Maybe a 753 or 843? Not familiar with any but my own. And if you've done 4 of those hoses, my hats off to you!!

 

[Chris 8603]

I won't do another one!!!
And won't take a $100 for the wrench I made. Time for someone else to do them!!!

 

[Dave1234]

I won't do another one!!!
And won't take a $100 for the wrench I made. Time for someone else to do them!!!

Can you post a picture of that wrench?

 

[Chris 8603]

It's not much to look at!!! But yeah, the next time I'm at the shop I sure will

 

[laurencen]

when we repaired the old 743 we had to make several wrenches and sockets, seems every time we tried to fix a peak we needed a special wrench, most we cut a standard wrench and bent it to get in the space, not sure how the dealer does it but in some cases it was easier to remove the motor

 

[Chris 8603]

Your right there. I quess they have magic!! Lol!!

 

[wwb]

Are you sure it is hydraulic oil? I have a 1986 843 that had an oil leak when I bought it. I finally found out that the rear seal to the motor was leaking and making a mess of oil. It also shot oil all over the radiator which caused overheating on the motor when the rad got plugged up.

 

[Chris 8603]