Strange BX 24 Hyd Fluid Leak

[DickS]

Hadn't started the tractor in about three weeks. Plugged in the engine block heater for about ten minutes and started the engine. It was a little 'cranky' at first but smoothed out after two minutes of idle. Allowed to run another five minutes. Outside temp is 15*F with overnight low temp around 5*F.

I raised the ballast box and FEL then drove the tractor at 2500 rpm for 1/2 mile, turned around, and returned the tractor to the shed. I shut the tractor off but neglected to lower the ballast box. I went to the house for about 10 minutes and when I returned I noticed hyd fluid pooling between to two rear wheels, perhaps a cup full. I lowered the ballast box to find the source of the leak. It "appears" to be coming from a plastic cap; black, with a red button like center located above the PTO on the top of a rectangular protrusion, right between the BH connections. I checked the fluid level and it registered on the stick but not by much.

I know this is long winded but I wanted to give as much of the operating conditions as possible.

Any ideas about the cause of this leak?

 

[Volfandt]

Sounds like the pressure relief valve was letting off some pressure.
I'm not too familure with the BX24 but on the BX23 the PRV is in about the same position and is as you described.

Cold hydraulic fluid builds up pressure faster and higher than hydraulic fluid thats been warmed up to normal operating temp.
Couple your fluid being operated and not reaching it's normal operating temp with the 3PH bleeding down with a heavy load on it, I'd say the system pressureized to a point to where it tripped the relief valve.

I would recommend to lower all hydraulic loads when you shut down, especially in winter. i.e the 3PH & FEL.
Top the fluid off then just monitor everything for future leaks.

I've had my FEL repressurize once when it was dismounted. Ends up that I didn't fully relieve all the pressure on it before I dismounted it and the fluid that remained pressurized when the rams started to bleed down over time. It's always good policy to relieve all pressure when the tractor is shutdown.

 

[DickS]

Is that the pressure relief valve? The black plastic cap with the red button-like top?

 

[638]

On my BX23 that 'black plastic' is made of rubber and the red button in the center is the transmission vent. You can grab it with a pair of pliers and pull it out. I pull mine out and use a vaccuum pump to draw a vaccuum on the case to change the filter and clean the screen, very little oil lost that way. I don't know why you would have oil comming out of the vent.

ron

 

[rdsaustintx]

Is tranny oil level too high?

 

[DickS]

I don't believe so. As I said, the fluid level registered on the stick, but not by much. Actually, I could visually see the fluid in the resevoir.

 

[techman]

You may have been on the high end of the level, and when the implements were removed you may have been at a very full level. Add the very cold weather, which possibly could have allowed some trapped air to not escape (due to high viscosity) you hay have just had the correct combination of circumstances to cause an overflow. The red cap you described is the breather, as mentioned by others. I would not panic and just monitor the level and any future venting. If all is well, I think you may have just been high on the level.

paul

 

[DickS]

Just talked to the dealer service manager (before I read the last post) and he is of the same opinion. He indicated all sorts of funny things can happen to hydraulics when there is very cold weather. The fact that I drove the tractor for a mile and warmed it up before doing so did nothing to warm the fluid for the lift cylinder. Ergo, the possibility of fluid escaping from the vent if the level of the fluid was high to begin with.

Dang, I hate fluid leaks. Got rid of the Harley D because it wouldn't stop leaking.