753 Oil Leak

mitchash · Jul 20, 2011

I just bought a Bobcat 753 that I knew it would need some work but for the price I couldn't pass it up. It runs and works well. The owner said it had a axle seal leaking. I did notice a small leak towards the back but all the levels were in the safe part on the dip stick. Last night I went out to the garage to look at something and noticed a big puddle of hydrulic oil under and on the right side of the skid steer. I didn't have time to see where it was exactly comming from. Could it be the axle leaking that bad? What would be involved with replacing seals on this machine? I can do most of the work on it myself and I have a friend that's good at working with this stuff. Where can I get a service and parts manual?

mitchash · Jul 22, 2011

I finally got a better look at it, the axles seem ok not much oil there. The hydraulic oil seemed to be coming from under the engine in the back. I tipped up the caged and the pump in the back (the one that the levers go to that control the speed) is wet with oil, I can't tell if its the seals or a hose. How big and expensive of a job is this going to be to fix?

mitchash · Jul 24, 2011

Where is the best place to get a service manual for my 753?

mitchash · Aug 3, 2011

My 753 seems to have leaked most of it's hydrulic oil out just sitting in the garage. I haven't ran it in a couple of weeks and the oil level was good then. Now the tank is about empty and there is a huge puddle of oil that seems to be comming from under the engine in the back or between the seat and engine). If it was the tandem pump (which is wet with oil) it would need to be running to leak like that wouldn't it? Thanks, Ash

SSdoxie · Aug 3, 2011

The hydraulic tank is just above the gear pump. So any leak in the tank or lines and fittings into will drip on the gear pumps. Check for leaks in tank itself, suction hose from tank to gear pump, and case drain line (small hose going into bottom of the tank).

mitchash · Aug 5, 2011

The tank and bracket on top of the drive pump are dry. I need a steam genny to clean this thing!

mitchash · Aug 21, 2011

My 753 has leaked most of it's hydraulic oil out. I need to move it to clean and repair. Can these be moved with a tractor or winch without running?

SSdoxie · Aug 21, 2011

If it is a slow leak, better to put some oil in it and drive it then drain oil back inot a clean container and reuse it. Brakes are locked with engine off, so you can drag it but no good way to tow and allow wheels to turn.

SAPP99 · Aug 22, 2011

I WAS READING YOUR PROBLEM ABOUT A HYDRAULIC LEAK AND I HAVE A COUPLE OF SUGGESTIONS. MY FIRST SUGGESTION WOULD BE TO CHECK
AROUND THE ALUMINUM TRIANGLE LEVERS THAT ARE BOLTED TO SHAVES ON THE HYDROSTATIC PUMP AND ARE HOOKED UP TO THE BLACK STEERING LEVERS. IF THERE IS HYDRAULIC OIL AROUND THERE THEN YOUR SEAL AROUND THE SHAVES ARE FLAT OR WORN. BOBCAT CALLS THESE SEALS PINTLE SEALS.
SECOND SUGGESTION WOULD BE TO CHECK THE HYDRAULIC HOSE THAT RUNS FROM THE BACKSIDE OF HYDROSTATIC PUMP TO THE HYDRAULIC FILTER HOUSING TO SEE IF IT IS LEAKING.
MY FINAL SUGGESTION WOULD BE TO CHECK BETWEEN THE TWO HALVES OF THE HYDROSTATIC PUMP. THE HYDROSTATIC PUMP HAS TWO SECTIONS ONE FOR THE LEFT SIDE DRIVE AND ONE FOR THE RIGHT SIDE DRIVE AND THE TWO ARE BOLTED TOGETHER WITH A METAL GASKET IN BETWEEN THEM.
LET ME KNOW WHAT YOU FIND GOOD LUCK.

mitchash · Aug 24, 2011

I haven't had a chance to take it apart yet but I do notice that the left steering pump is wet with oil. If it was the pump seals leaking would it still drain the oil tank without running? The tank went from full to low in a few days. I'm hoping it's just the hoses in the rear of the pump.

20 20 · Aug 24, 2011

mitchash said:
My 753 has leaked most of it's hydraulic oil out. I need to move it to clean and repair. Can these be moved with a tractor or winch without running?

My case SS STRONGLY warns against moving the machine...........unless the relief bolts are turned to allow slow towing/pushing SHORT distances. I would bet yours would be the same, there may not be a relief bolt/valve but you'd probably need to unhook a line or.......?????

20 20 · Aug 24, 2011

mitchash said:
I just bought a Bobcat 753 that I knew it would need some work but for the price I couldn't pass it up. It runs and works well. The owner said it had a axle seal leaking. I did notice a small leak towards the back but all the levels were in the safe part on the dip stick. Last night I went out to the garage to look at something and noticed a big puddle of hydrulic oil under and on the right side of the skid steer. I didn't have time to see where it was exactly comming from. Could it be the axle leaking that bad? What would be involved with replacing seals on this machine? I can do most of the work on it myself and I have a friend that's good at working with this stuff. Where can I get a service and parts manual?

Manual= dealer, or check out heavy equipment forum, or the skidsteer forum.

You'll have to trace the oil leak back until you can find the problem it may be a pain or it may be in plain sight???? There are countless places it could be leaking from and with the design of the machine it may be in a completely different area as to where it is dripping on the ground. Sorry I can't be of more help check out the sites I suggested above, those folks know their stuff when it comes to machines like this.

SSdoxie · Aug 24, 2011

mitchash said:
I haven't had a chance to take it apart yet but I do notice that the left steering pump is wet with oil. If it was the pump seals leaking would it still drain the oil tank without running? The tank went from full to low in a few days. I'm hoping it's just the hoses in the rear of the pump.

If there is a seal around shaft to pump leaking, it can drain down without running. The tank is above the pumps and has a vent cap on it, so if oil can get out air will come in the top and eventually drain the tank.

SAPP99 · Aug 25, 2011

If the pintle seals around the shafts are leaking then yes because your hyd. tank sits up above the hydrostatic pump and it will gravity feed into the hydrostatic pump. Of course anytime you run the machine it will leak more.

mitchash · Sep 6, 2011

Looks like a combination of stuff leaking. There are a couple of hoses that need to be replaced, also the Pintle seals are leaking (seals on top of the hyd. pump where the steering valves are). Anyone ever replace those seals? How big of a job is it and how much are the seals? Anything else I sould replace while the pump is apart? Thanks

SSdoxie · Sep 6, 2011

You do not have to take the pump apart to replace the pintle shaft seals. Remove the return to centering plate and the pintle arms where they clamp on the shaft. Drill a small hole towards outside of the seal, screw in a sheet metal screw and pull old seal out and replace it. Hardest part is reinstalling the centering plate and getting it adjusted. Make sure the machine is jacked and blocked off the ground when you start it. If you have the cast aluminum style pintle arms it is a good idea to replace these and new cam blocks while you have it apart, these are the most frequent wear items in that sterring system.

mitchash · Sep 13, 2011

I ordered the pintle seals and o rings that are under the pintle seal covers today. I am hoping I can mark the steering linkage before I take it apart, then take the pintle covers off, replace the seals and o rings and be back in business again. At least thats what it looks like I can do from what I see in the service manual.

SSdoxie · Sep 14, 2011

marking location of all the linkage is best way to do it, get it close. You will still have some fine tuning to the neutral so be sure to have it raised and block off the ground when you first start it up.

mitchash · Aug 24, 2012

I had to take the cab off my 753 because the plate where the seat bolts too was rusted out and needs to be rebuilt or the whole cab could stand to be replaced or rebuilt. While I have the cab off I am finally going to replace the pintle seals. Do I need to take the hyd tank or anythig else off (besides the steering linkages) to get to the seals?