Oil & Fuel Oil foaming in trans, Normal?

[Ralyjohn]

The oil in the trans is foaming when running tractor, doesn't seem to cause any effects to operation of FEL or BH. Only thing I hear is when moving BH side to side there is a sort of gushing sound of the oil going through the valve. Is this normal with the BX24 Hydro trans? It will fill the air space in the trans right up to the check dipstick. Seems to be doing this since first oil change at 50 hrs, at least that is when I noticed it for the first time. Can't find any leaks of oil any where that would indicate air being pulled in from any hyd. system connection. I don't run it hard, usually about 2200-2500 rpm.

 

[oldnslo]

That much foam does not sound normal. Does this only happen when using the BH or does it happen all the time?

 

[Ralyjohn]

Happens all the time, weather BH or FEL are on or not, for just mowing. Tractor has 500+ hrs on it, happens with SUDT or UDT fluid. Dealer told me they only use SUDT in warranty repairs.

 

[oldnslo]

My BX 1850 does not do this but it does not have the BH attachment either. Does the tranny seem to get hot or make any excessive noise?

 

[Ralyjohn]

Tranny is not noisy, had it to dealer to be checked, I thought the trans was getting too hot, would steam water off if washed when hot, but normal temp is 100 deg above ambient according to dealer. I checked it one time on 80 deg day and it was around 170 deg with digital thermocouple for my DMM.

 

[oldnslo]

Can you try a simple test?

I don't care which function you use but can you operate either the MM mower raise until it stops or one of the FEL controls until the cylinder stop moving. Do you here the relief valve at this point? Does the engine labor any more or change sound from when the function is moving Vs stopped?

A stuck or leaking Relief valve can cause foaming and will also cause excessive heat.

 

[Ralyjohn]

I can hear the relief valve working if I hold the up handle for the MMM. The RPM goes up when released. I requested a parts diagram for the trans from Messicks to try to see where the relief valve is so I can check for it being stuck open or such. The BX24's don't have any hyd pressure for the attachments till the RPM is above 1600, I understand that that has been changed on the newer BX25/26's that they will have HYD pressure at idle for the FEL and BH.

 

[dodge man]

Mine will be a little foamy when I check it after being used, but not very much, not enough that it has alarmed me. Could a slight air leak cause this?

 

[Peacock]

I would make sure that the vent is in good working order.

 

[kuboman]

When was the oil last changed?
Does it sit outside. I would wonder about water in the oil. Water will cause hydraulic oil to foam.