Bobcat 753 hydraulic oil suddenly low?

[dieselfuelonly]

With the hydraulic fluid level low would I be OK to start the machine for about 2-3 minutes and drive it from the barn to the inside of my garage? I don't have any extra oil and the nearest dealer is about an hour away.

[EDIT]

Also, if/when I get it in the garage, are there any special measures I should take before going to work? (i.e. leave the boom up, etc).

[ANOTHER EDIT, SORRY ]

I realize I'm going to need to purchase a service manual for this... Not cheap, but, I don't see any other way. However, I probably won't be able to get one tomorrow. Lets say the chain case is overfull and its pretty apparent that a seal is bad. Are there some simple things I can start doing tomorrow until I get a service manual just to get things moving along?

 

[AKfish]

You won't hurt anything to drive it that far.. it's not "dry"; it's just low.

Better be lookin' for a bunch of old rags and floor dry! You're gonna need 'em!

I think I'd visit with the local Bobcat guys and pick their brains a bit, too. You're likely gonna be talkin' with them about parts and maybe hyd fluid in a short time as well..

Best of luck and let us know how things turn out.

AKfish

 

[gatractorman]

You'll be ok to drive a little ways, boom arms up and locked and cab flipped back is how it always starts when you do almost anything to a Bobcat. I think I have a service manual for a 753 at the shop, let me look today at the setup it has, the more I think of it the more I think you may have one you can change seals with just a drive motor removal.

 

[dieselfuelonly]

Man I love this forum. Everyone is so helpful - thanks.

When I raise the boom, is there a way to "lock" it in place? I know the cab tilt has a little clip that locks into place when you lift it up to a certain height. I guess I'll take the bucket off too.

 

[gatractorman]

Bucket off is a good idea, there is supposed to be an orange safety lock bar above the right boom arm cylinder (as viewed from the operators position) thats held up with a pin and may have a spring hooked to the pin as well if everythings there. Anyway pull the pin, raise the boom arms and the bar will fall down over the rod and will keep the boom up.

Your in luck, it is possible to change motor carrier seals on your machine by removing the drive motor. It's not easy but is possible.

Take the access panel off that is between the tires, you will see the end of the drive motor. There are 2 large hoses that need to be marked as to which fitting they came from, I have a hydraulic plug and cap assortment that thread in the hose and over the fitting with numbers stamped in them to identify position as well as stopping fluid leaks and dirt contamination. Then you will have 1 smaller hose to remove. 4 bolts hold the motor to the carrier then off comes the motor.

You will see the seal in the carrier once the motor is out of the way, its a quite large seal mabye 4" across and it seals around the shaft in the middle. Those small slide hammers with what looks like coarse screw threads on the end that screw directly in a hole that you would drill in the old seal should pop it out, may have to drill in 2 or 3 places. Careful dont let the drill bit go far thru the seal there is a set of bearings close behind the seal. If you haven't drained the chaincase you will start getting oil now. Bobcat says to use a special driver tool to install the new seal but a pipe or something that fits the O.D. of the seal works fine if you are careful.

Check the bearings in the carrier while the motor is off, pry up,down,back,forward also in and out motion of shaft.

To drain the case, under the back of the machine is a small plate held on with 2 bolts after it is off find a small rubber plug with an aluminum plug in the middle of it at the back bottom corner of the chaincase. There is another plug just like this one under that plate that drains the fuel tank but it is positioned in a way that you can tell it wont drain the chaincase. The aluminum plug is what comes out with some kind of forked tool, just pry it out, alot of times the rubber bushing comes with it but no big deal. Depending on how full the case is be prepared to catch 20+ gallons.

Anything else just ask.

 

[dieselfuelonly]

OK - heres the update. I took a video of my discoveries, but I can't find my cable to hook the camera to the computer - I'll pick up another cable tonight, I think I left it down at my college over spring break. Oops. Anyway, heres what I found:

Machine started up like it was running yesterday. At least the engine runs good! No weird noises, drove it from the barn to my garage and everything seemed normal. Since I didn't want to hit the ceiling of my garage with the bucket, I went ahead and took it off and then drove the machine in the garage.

It took me a few minutes to figure out how that boom saftey lock things work. I didn't realize it would work automatically, so I did get out of the machine with the boom raised to manually pull the boom lock out. Since you said it will work automtically if you pull the spring off, next time I will do it the right, and safe way.

Next I removed the plug from the front of the machine, right above the metal loop that chains can be run through. Nothing came out. I stuck my finger in there and still didn't touch any fluid other than some gunk around the plug threads. That doesn't sound right, I think I remember reading that when filled correctly you can just stick your finger in there and you should touch fluid just below the fill port, correct?

I tipped up the cab and took a somewhat closer look around. The hose with the white "filter looking" thing (not sure if its a filter, water separator, or what) directly under the hydraulic tank was somewhat damp with what appeared to be hydraulic fluid.

The video will probably explain a lot more than I can, so I'm going to run and go get a cable now and upload the video.

gatractorman - I owe you big time for all the help.

 

[dieselfuelonly]

Here is a link to the video:

YouTube - Bobcat 753 Troubleshooting Part 1

 

[radman1]

Watched your video. One thing noticeably missing was any cursing. The chaincase certainly wasn't overfilled. You have to be losing it through a valve, fitting or hose. My 873 was losing it from an O ring in the valve and leaking. 36 cent part with $300 labor. However, on my 873, I was having problems with the boom cylinders leaking down too fast. The hydraulic fluid you noticed on the hose may be the location. You will just have to clean everything off, then run the unit and recheck.

 

[dieselfuelonly]

One thing noticeably missing was any cursing.

Oh don't worry, I edited it out so it would be suitable for this site. There was plenty "off camera"! You will notice the pause when I put my finger in the hole and it came out dry, I had to edit that out...

Thanks for watching the video, I hope it wasn't too long, I wanted to provide as much info as possible.

The chaincase should normally be filled with fluid up to the plug that I removed, correct? Should I just buy the cheapest weight oil that is suitable and fill it up and see what happens, along with topping the hydraulic tank back off?

 

[irwin]

I'm following this Dennis.

I'd fill all fluids to spec and thoroughly clean/degrease everything I could get at, dry it off, then start her up, work all the controls and see if there's any new leakage. But lets hear what gatractorman has to say.