B7500 Hydraulics

Anonymous Poster · Apr 18, 2001

I have a B7500 with an FEL that I really only started using a week or so ago to move a pile of
dirt (purchased this in January; have about 15 hours on it).

When using the FEL, I notice a steady drip of hydraulic fluid coming from the control box that the
lever is attached to and that the four hydraulic hoses from the FEL plug into. The dripping was
not coming from the hose connections, but somehow underneath the control box.

I pulled the yellow hydraulic dipstick that's next to the HST rear pedal, but the fluid is (presumably) clear
and I could not really determine the level of fluid in the tank.

I looked in the tractor manual, but there is nothing relative to the hydraulics in there; it does not even
show the dipstick in the diagrams.

Is the dripping normal? Is this some type of pressure release remedy? I wouldn't think it is, as the dripping
was pretty constant while the REL was in use.

I had a front mounted snowblower in the winter, and never noticed any fluid leaking with that use (but
there is much more use of the hydraulics with the FEL than with the blower).

What happens if the fluid level gets too low? Will the FEL simply not work as well or will I be harming
the mechanics by continuing to use the hyrdraulics with the fluid too low (ie: is it as bad as letting the
oil get too low?).

I don't know if something may be loose inside the hydraulic box; once again, there's nothing in the manual
regarding the hyrdaulics and I'm hesitant to starting pulling things apart and really screwing it up.

Thanks

skent · Apr 18, 2001

Snowman,

No, it shouldn't be dripping from the control valve. It's possible that one of the male hydraulic couplings (screwed into the valve) is not tight. I have a very similar setup (B7300HST) with over 200 hours and it doesn't drip at all.

As far as the level of the oil, It should be on the bottom inch of the yellow dip stick. If your HYD oil is clean, you might need to view the dipstick under a bright light to see it's level. If its low, better add some real soon. . . . your transmission IS basically a big pump, pumping oil (when you press the HST pedal) to a oil powered motor, that turns the rear wheels (basically). There is a device call a charge pump that provides hydraulic oil to the big pump to keep it 'lubed'. If you hydraulic oil level drops, you don't get lube oil, (or a mix of oil and air) and could damage the HST. Very similar to running your car engine when the oil light is on.

Let us know hew you make out

Steve
"Give me Anbiguity, or give me. . . . . . . .something else"

Anonymous Poster · Apr 18, 2001

Thanks - are the male hydraulic couplings all on the exterior? In other words, if I just make sure that
everything that I can see on the exterior is tight, then there's nothing inside that I would be missing (in
other words, once I've made sure all of the exteriors items are tightened, there nothing left to tighten?)

Bird · Apr 18, 2001

That's about it, snowman, just make sure all the fittings and connections are "tight". Naturally, I'd shut off the engine, move the joystick in all directions to make sure there's no pressure on any of the lines, and then check all the fittings. And you don't have to pull hard on a wrench; just good and snug should seal unless there's something wrong with one or more of them.

Bird

Charliebrn · Apr 18, 2001

IMHO, the tractor is brand new, and NO it should not be leaking fluid of ANY kind. Call the dealer and see if he'll come out and fix it. You shouldn't have to deal with it and risk causing more problems than you already have....

GlueGuy · Apr 18, 2001

Snowman,

My B7500 has 26 or 27 hours now, and there are no drips whatever. I do get a little drip when I pull the quick disconnects, but after cleanup, it all stays dry.

I check the fluid level when the machine is cold. The fluid is very clear. What I do is pull the dispstick out & dry it off completely. Then I put it back in & out to check. If you hold the dipstick under a light (or hold it under sunlight) & at an angle, you can see the shinier surface that is coated with fluid versus the dull/flat surface of the dipstick.

The GlueGuy

Anonymous Poster · Apr 20, 2001

In case anyone's interested, the cause of the hydraulic leak was that a hex cap bolt at the bottom
of the control unit was missing. Had to stick my head next to the front wheel and look up to see it.
Was the bolt between the "in" and "out" hyrdraulic lines.

These seem to be rather sturdy bolts, so it must have been loose when I received the tractor and
then, as oil probably slowly leaked out, it became "lubed" and eventually dropped out completely.

I purchased another bolt at an auto supply store and it seems to work fine. I also checked all of
the other bolts; some were a little loose.

It appears that I didn't lose too much fluid, as it seems to be above the first notch on the yellow
dipstick still. Unfortunately, the dealer that I purchased the tractor from went out of business last
month and there's nobody locally to service it or buy supplies from.

Thanks to everyone for their suggestions and advice.