Bobcat 753 - Pulled engine, fixing leaks and fan drive.

[colson04]

Finally pulled the Bobcat into the heated shop for some long overdue maintenance. Threw the fan belt last week, found the tensioner has failed.
While in the shop, I thought I'd address an engine oil leak. Now I'll be replacing: fan belt, drive belt, alternator belt, fan drive pulley (its bent), the fan tensioner, the main drive tensioner, the idler pulley, all filters, 2 hydraulic hoses from under the hydraulic tank, and adjusting the steering as the left side has considerably more slop than the right side. To address some of the leaks, the engine has to come out, so I started disconnecting everything so I can pull the engine and pump together. Once out, I'm also going to pull the fan drive and reseal it as it appears to be seeping gear oil too.



If it hadn't been below freezing when I started, I would have power washed it before bringing it inside. The layer of grease, grime, and oil is really heavy in the belly of this ol girl. She's a Series C with 3200 hours on it.

 

[Welder Dave]

3200 hours doesn't seem very high to be needing all that work and having to pull the engine. Hopefully it goes back together relatively easy for you.

 

[1693TA]

As tightly as crap is packed into those things, it's a lot easier at times to pull the engine than work with it in place. That scenario plays out often at the implement dealership I help out with older New Holland skid steers.

 

[colson04]

@Welder Dave it may only have 3200 hours, but the machine is a 1993 model year (30 years old). I've had to replace multiple hoses on this machine already in the few years I've had it. The belts, tensioner, and fan drive pulley, I could do with engine installed. The engine oil leak is coming from the right side of engine, and possibly back side as well. Maybe even oil pan, not 100% sure. Engine needed to come out to address that. When pulling the engine, it's easier to pull the skid and take the engine/pump assembly as one, instead of pieces. You can't hardly reach anything between the engine and pump and this gives me a chance to inspect and clean while that assembly is out of the chassis. I'm doing it myself, so an extra week on this project doesn't change my costs, aside from possibly replacing more worn out parts.

 

[1693TA]

There is a lot of silicone used in the assembly of the engine with no gaskets. These leak pretty good over time. I just installed two oil pan gaskets on Grasshopper zero turn mowers this past week for this very reason.

 

[Welder Dave]

Isn't it a Kubota engine? They aren't known as leakers and use gaskets as far as I know.

 

[colson04]

Isn't it a Kubota engine? They aren't known as leakers and use gaskets as far as I know.

Yea, Kubota V2203. It is a very easy starting, smooth running engine, but this one definitely has an engine oil leak.

 

[willie59]

3200 hrs on a C series? Damn, that thing ain't even broke in yet! While you have the assembly out replace all the o-rings on the o-ring boss fittings on the pump, and that's 900 series o-rings, if you use anything else they'll fail. And you might as well replace the control shaft seals on the drive pumps, easy task, and even easier with them removed from the machine. You most likely have the one piece aluminum pintle arms on the pump control shafts with the hardened chrome spools, those things were damn near indestructible compared to the later model neutral centering spools, but if they're worn a bit, loosen the bolt that mounts them and spin them around for a fresh contact surface. Also swap around the plates that contact the pintle arm spools if they're worn. Replace the plastic bushings for the drive centering plate, and if the rubber linkage arm bushing are worn replace them too.

 

[willie59]

Oh, forgot to mention, before you tear that thing down toss the bucket. Jack the rear up with a floor jack and set stands under it so the rear wheels are off the ground, then use the loader arms to lift the front wheels off the ground to either use stands or wood blocks under the front to lift the front wheels off the ground. Then raise the loader arms and install the safety prop. Now...tear into it.

 

[1693TA]

IIRC that engine has a sleeve on the rear crankshaft seal riding area. The rear seal is in a carrier so both are easy to change. I don't remember the engine having an oil pan gasket but rather silicone as mentioned earlier. Both D722's I did earlier in the week, and my own D902 did not have oil pan gaskets. I have a Z482 from a truck APU to do yet this week that is a leaker, but I've not looked into it yet.

 

[colson04]

Oh, forgot to mention, before you tear that thing down toss the bucket. Jack the rear up with a floor jack and set stands under it so the rear wheels are off the ground, then use the loader arms to lift the front wheels off the ground to either use stands or wood blocks under the front to lift the front wheels off the ground. Then raise the loader arms and install the safety prop. Now...tear into it.

I did drop the bucket before I parked it in the shop. I hadn't planned on doing everything we are, so I wasn't smart enough to raise and lockout the loader arms before tearing way too much stuff apart. I was just telling my brother I should have done that, would have been easier accessing stuff. I didn't jack it up either. Is that a normal process for tearing one of these apart?

I appreciate the insight on clearing up the slop in the steering. I will check out those components before it all goes back together.

 

[willie59]

I did drop the bucket before I parked it in the shop. I hadn't planned on doing everything we are, so I wasn't smart enough to raise and lockout the loader arms before tearing way too much stuff apart. I was just telling my brother I should have done that, would have been easier accessing stuff. I didn't jack it up either. Is that a normal process for tearing one of these apart?

I appreciate the insight on clearing up the slop in the steering. I will check out those components before it all goes back together.

Not a normal process for said repair, but when you get done with said repairs you will have drive creep and that's one thing that is damn near impossible to adjust with the wheels on the ground.

 

[Old Doug]

I was going to pull my case in the shop this winter .It has several things going on but i have a job this week so it will have to wait.

 

[Acoals]

@Welder Dave it may only have 3200 hours, but the machine is a 1993 model year (30 years old).

3200 hours on a yard loader that runs 16 hours at a time is a brand new machine. 3200 hours 10 minutes at a time for 30 years on a Bobcat is a tired old girl . . .

 

[Welder Dave]

Depends if the leak is from not being used enough.

 

[colson04]

This job took a backseat while I waited on a service manual to arrive. I found a used copy in excellent condition on ebay for $55. It arrived Monday, but then work got in the way.

Finally back to it late today. Read the manual, saw they recommend a lifting device.

I rummaged my scrap pile, had all the bits I needed, so I built one.

 

[hosspuller]

Ohhh.... Home made lifting device ... Beware the safety nazi. need a Certificate and tag of some sort.

My safety "professional" was satisfied with a letter signed by me as tested at 3x expected loads. With alum tags stamped with serial number and load rating. Shudda put a pic of the test load in the file. That was more than 15 years ago. All about CYA

 

[colson04]

Meh,Safety nazi can gripe all they want. My garage, my Bobcat, my hoist, my decision. I think my lifting device is in better shape than my hoist right now. Hoist has definitely seen better days.

 

[Welder Dave]

Your welds look decent which is the most important. It is apparent to me that someone not very experienced designed the lifting device. The extra plates on the side look amateurish. Why not just put standard gussets on the inside of the corners? And the piece on the 45 has no gussets. Kind of funny actually but all that matters is if it works.

 

[Old Doug]

This job took a backseat while I waited on a service manual to arrive. I found a used copy in excellent condition on ebay for $55. It arrived Monday, but then work got in the way.

Finally back to it late today. Read the manual, saw they recommend a lifting device.
View attachment 280941
I rummaged my scrap pile, had all the bits I needed, so I built one.
View attachment 280938 View attachment 280939 View attachment 280940

Very cool i will have to remember that.