Bobcat 753 dumped its hudraulic oil.

[Antoekneel]

I have owned this bobcat for about 14 years and it has never given me any trouble other than once I had a condensation build up in the fuel tank.
Yesterday I lent to a friend in a neighbouring village so he could shift some soil. After about 1 hours work he said the bucket movement slowed down considerably and then shortly after he lost drive as well. After climbing out the machine he saw that he had left a trail of fluid along the 30 metre track. Now the machine is stuck and will not move.
If I put some hydraulic fluid in it will I be able to start it up and drive it straight on to a trailer?
Do I need to bleed anything?
How much fluid do they hold?
I have just changed the hyd fluid in my Kubota tractor so I have the old 10 litres I can use to hopefully get the bobcat moved.
Any helped really appreciated as its stuck in a really awkward place.
Cheers.

 

[ZekeSkyree]

I would try to determine the leak first. Might be as easy as swapping a hose.

 

[KyMadMan]

If you can get the trailer to the bobcat you can move the bobcat by pushing the controls in the direction of the trailer and use another vehicle or winch to get it loaded. You have to hold the control levers or it will not move.

 

[mrbb]

I agree, you need to find leak first, or you will just be wasting more hydraulic fluid

 

[Antoekneel]

Thanks for the replies, how is the best way to find the leak, everything is so oily & dirty.
It seems to be to the right hand side of the engine, looking from the rear door. I thought I would need to use a power washer to clean everything first. Please let me know if this is a bad idea.
Is it then best to put some Hyd fluid in and then run the machine to hopefully spot the leak?
Sorry if these are dumb questions, but I really hope I can fix this myself.

 

[mrbb]

I would start with trying to wipe up and remove as much fluid and such, to clean things, WITHOUT using water or for sure a pressure washer
as if you have an exposed opening some place you do not want to be pushing water into it!
I would suggest using a bunch of old rags, towels, and such to clean as best you can
from doing this alone you may find the leak, as in finding a blown hose, or likes!
if you gone 14 yrs without replacing a hose, this is a high probability of the leak some place, as hoses go bad from time passing alone, as they do dry rot and then when used(all the more so if used hard) they will fail on you
I would also be suspect to the person you had running the machine,a s to NOT seeing any lights pop on showing there was low fluid levels, as most machine have these

there to prevent you from running the machine when things get too low and doing damage to pumps and other parts! that get costly really fast!


After you clean best you can, if you still have NOT found the leak
then I would suggest adding some fluid, enough to fill pumps and drives
you can also, BUY DYE you add to hydraulic fluid, that helps find leaks too!
so adding some of that is not a bad idea, if you wanted too , its cheap and typically easy to find at shops that sell parts for machines! and even at many auto parts stores too!


from there you want enough fluid in system to run things, without doing damage to things

from there I would have someone start the machine, and have them be ready to shut it off REALLY fast
as hydraulic leaks can have serious pressure behind then that can harm or even KILL a person
I would then stand in a safe spot where you can se things,(i'd wear safety glasses too and or other protective gear hydraulic fluid can be toxic if it gets into your body!

SO< again once fluid levels are up to safe starting level
have a person start while YOU or others watch(or set up a video camera of some sorts)
start machine, look for leak
and shut down FAST, so not to waste more fluid, and or run pumps dry again! if they were !


YES there will be air in the system most likely, but that can be resolved after you find major leak

as if it dumped all its fluid in a BIG trail, its likely a BIG leak some place

so you should be able to see it leaking once started
and from there, fix, what is wrong!

be careful and please update as you find out what is wrong and the fix needed to resolve it


ALSO< once you do fix leak and get things running right
its NEVER a bad idea to THEN do a GOOD cleaning, starting with a cold , add some good de greaser, to clean and remove built up gunk, let soak a while, , and then use a good garden hose to rinse things, or a mild pressure washer, or some good old elbow grease using a what ever needed, brushes, scrapers and so on!

having a clean machine, will add life to any machine and make any future repairs easier! , not to mention, less of a fire hazard!


Good luck!

 

[mrbb]

also I did a quick search on amount of fluid and found this

also be aware that some of these older bobcats, use motor oil and NOT hydraulic fluid, and then many BOBCAT models use special BOBCAT hydraulic fluid and not a universal fluid
that is your your going to follow what BOBCAT tells its owners to use!
I know many folks do Not always follow the OEM"S specific fluids they suggest to be used, and just use what they feel is better or, ??? just use what they want,.have, can get and so on!

but just so you know, to maybe look into things before just filling with"X brand make fluids!

also, a link to some info for you on your model(will don't know your exact model, as they make several 753 models over the yrs from what I know!
using your VIN will get you exact spec's from any BOBCAT dealer too in case you didn;t know that!

[td width="500px"]Hydraulic System[/td]

Hydraulic System Type ...................... Open center
Hydraulic Pump Type ...................... Gear
Pump Capacity, gpm (Lpm) ...................... 15.9 (60.1)
System Pressure, Bar (psi) ...................... 190 (2750)
Hydraulic Reservoir Capacity, gal (L) ...................... 3.5 (13.2)
Hydraulic System Capacity, gal (L) ...................... 6.0 (22.7)

 

[Rockin Ranger Rider]

I had a similar situation one day on my little Daewoo. I was just pulling out my side by side from a mud pit after a rain and as I rounded the corner the drive became sluggish so I had the foresight to jump out and open the rear engine compartment door . At this point the motor was shut off but the problem became obvious. The hydraulic filter had been blown out at its base probably because of a build up of moisture. Fortunately although on a Sunday it turned out to be a thirty minute $50.00 fix thanks to NAPA , good luck with your search!

 

[Antoekneel]

Thanks everyone for your help, especially Mrbb for such great detail.
It has taken me the whole day to recover the Bobcat and get it home.
I managed to tow it up onto the trailer, and once home it rolled off my beaver tail trailer with a little persuasion.
I lifted the cab and had a look around, unfortunately couldn't see anything obvious, although it's definitely the right hand side of the machine. I then took the cover plate off, from between the wheels, looking inside here I saw what looks like a green lid (looks like the lid from a shampoo bottle). It was just sat there on the bottam, about 6 inches to the left, and it was full of hydraulic fluid. You can see the green lid in the photo and that is roughly thow far back it was found, but obviously under the pump/motor or what ever that is under that bunch of electrical connectors.
So that's where I am right now.
Thanks again for all the help and any advice for my next step would be hugely appreciated.
She is a Bobcat 753 G-series 2000 serial 516220519 and has done just under 2000hours

 

[mrbb]

your machine should move when pulled .pushed, if you have someone inside it push the levers in the direction you want to move it
as to trying to just drag it/manhandle it
just so you know!
that is as long as nothing in the drive train is binding that is!`
but pushing levers in direction, tends to lower the resistance required to move a dead machine(or on MANY older ones that is, newer one and some models this will not work on, but yours it should!)

as for the green lid you found, that could be from a bottle of fluid some one once added and it fell into the machine, or, likes!

I don't think its any source of your leak!

I would look good at the hydraulic /oil tank and the hoses coming off it for your leak.
I would also be checking your motor oil level, and confirming you didn;'t loose that!

as I do believe on your make/yr/model, it used 10w30(or 40)W) for its hydraulic system!


IF again you cannot spot leak without running machine

I would buy some dye, add to hydraulic tank, and fill to a safe level, and then start machine and be careful looking for leak, with OUT running the system down too low
so you do not damage things

once running the leak should be more easy to find,as if it dumped it all so fast I
d have to think you have a BIG leak some place
just be safe,a s hydraulics leaks under pressure can be very dangerous!

 

[Ceilingwalker]

Thanks for the replies, how is the best way to find the leak, everything is so oily & dirty.
It seems to be to the right hand side of the engine, looking from the rear door. I thought I would need to use a power washer to clean everything first. Please let me know if this is a bad idea.
Is it then best to put some Hyd fluid in and then run the machine to hopefully spot the leak?
Sorry if these are dumb questions, but I really hope I can fix this myself.

I have the exact same machine, 1995. I recently had the exact same problem. I started the skidder, lifted the cab, actuated the pedals and found a cute little slit in a hose. Never would have seen it without fluid flowing and it was dumping a lot of oil. New hose, no more leak.

 

[icecheez]

I just got a 753 G series. It would dump a gallon of fluid in a few minutes. None of the hoses or fittings were wet, but the bottom of the right side was full of oil. Turned out the hose coming from the pump going to the bucket positioning valve(I think) Anyways, where all the hoses and hardlines go to on the front right under cab. The afor-mentioned hose goes down below the rear axle, along the bottom for a few inches, then up to the bottom of that valve block. I discovered it after putting a half gallon in, running a minute, then while squirming around looking for the leak, I stepped on a pedal accidentally and heard bubbling in that puddle of oil at the bottom of the case. since there was only that single hose down there... The fix was to remove the tires, the drive motor and the hoses attached(protect the ends from dirt), there's a little plate a few inches aft of that to remove that allows access for a wrench to remove the fitting of that hose. Reach through the motor hole to orient the hose on install, be sure to use a plug or something to keep dirt out. I had a plastic threaded plug. remove the hardline coming from the pump and pull it out. Mine rubbed on the bottom of the case until there was a hole in the hose. The previous guy had added oil trying to figure it out then it sat for 5+ years. I had a friend make a hose for me, now it's golden. mine takes 10w30 motor oil or tractor hydraulic fluid.

 

[Antoekneel]

I just got a 753 G series. It would dump a gallon of fluid in a few minutes. None of the hoses or fittings were wet, but the bottom of the right side was full of oil. Turned out the hose coming from the pump going to the bucket positioning valve(I think) Anyways, where all the hoses and hardlines go to on the front right under cab. The afor-mentioned hose goes down below the rear axle, along the bottom for a few inches, then up to the bottom of that valve block. I discovered it after putting a half gallon in, running a minute, then while squirming around looking for the leak, I stepped on a pedal accidentally and heard bubbling in that puddle of oil at the bottom of the case. since there was only that single hose down there... The fix was to remove the tires, the drive motor and the hoses attached(protect the ends from dirt), there's a little plate a few inches aft of that to remove that allows access for a wrench to remove the fitting of that hose. Reach through the motor hole to orient the hose on install, be sure to use a plug or something to keep dirt out. I had a plastic threaded plug. remove the hardline coming from the pump and pull it out. Mine rubbed on the bottom of the case until there was a hole in the hose. The previous guy had added oil trying to figure it out then it sat for 5+ years. I had a friend make a hose for me, now it's golden. mine takes 10w30 motor oil or tractor hydraulic fluid.

Thanks Icecheez,
That sounds very helpful.
Is the bucket positioning valve what you can see in my third photo above? in line with the screwdriver handle?
Many thanks

 

[Antoekneel]

I still have not managed to find the leak. I have been cleaning and doing some electrical wiring repairs until I can get to the shop to buy some more fluid. How much would be a safe amount of hydraulic fluid to put in to help find the leak, I know that I will loose it fairly quickly, so don't want to waste too much.
Having studied my ow photo above I noticed that there was something that stood out as being so much cleaner than everything else, and sure enough that green cap fitted it perfectly, and was obviously on it until fairly recently.

 

[mrbb]

IF you have any removable skid plates, that may allow you to see things better from the bottom, to help find your leak(plus removing them tends to help with cleaning things)
I would suggest doing so!

as for a safe amount of fluid
honestly , safe level is normally at the low? MIN mark on your tank
when you run low , you rick damaging costly pumps, and getting air into system

SO< its better to be safe than sorry, or that;s MY opinion

IF your machine uses 10w/30(or 10w/40) there are some cheaper options, to use to find the leak and then once resolved, maybe drain and refill with better brand of oil!
, and replace filters too

or that's whats I'd suggest doing!

 

[sunnyboy]

Sounds exactly like what happened to me a few years ago. Long story short, you've blown one of the larger hoses.

Tilt up the cab and look down both sides and you should see a nice deep pool of hydraulic oil on one side (mine was on the right from driver's position). The hose connections on the back are miserable to get a wrench on - I had to buy stubby 1" and 1-1/4" ones to get the fittings off and to put the new line on. I'll see if I have photos of it...

 

[sunnyboy]

Sorry, no photos of the leak or work. Only a photo of the blown hose - the leak is subtle - hose was totally intact but the outer case was worn thru from long hours working.

 

[Antoekneel]

5 months later I finally found some time to try again to find the leak. As Mrbb suggested I put in 7 litres of 10w/30 oil, lifted the cab, I then started her up and after about 30 seconds the leak was very easily spotted. It gushed out with such force. I think it's the valve that controls the tilt and lifts the arms. It is where the green lid was fitted in the above photos which I posted in July. Here are some photos of the oil leaking through the small hole that is in this end cap. Im hoping someone will be able to tell me exactly what part this is and what seals or O rings I will need.
TIA

 

[brdgbldr]

Here is a link to the parts catalog:

https://partscatalog.bobcat.com/

 

[Rockin Ranger Rider]

Thanks for the replies, how is the best way to find the leak, everything is so oily & dirty.
It seems to be to the right hand side of the engine, looking from the rear door. I thought I would need to use a power washer to clean everything first. Please let me know if this is a bad idea.
Is it then best to put some Hyd fluid in and then run the machine to hopefully spot the leak?
Sorry if these are dumb questions, but I really hope I can fix this myself.

I was fortunate enough to see my leak occur otherwise I would have been in the same predicament, mine was a blowout at the very bottom of the hydraulic filter. I’m thinking some water made the bottom of the can rust out over time. A possibility for you?