20,000 Posts & Climbing
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Re: 455 Transaxle Temperature
You're at the limit for max operating temperature. For hydros, and hydraulic systems in general, normal recommended max operating temp is 180°. Max temp is 192-195°. Above this temp, the fluid begins to lose its ability to transmit power due to reduced viscosity. At 225°, the fluid begins to carbonize (burn) and the carbon particles cause accelerated wear. This is where the killer for the much maligned K46 resides.
Periodic 'rest' times are indicated to keep the temperature under control for that particular task. A 'rest' of a few minutes at high idle with the drive in neutral should lower the temp to a safer level if it gets any higher.
Ensure that your radiator fins are clear and the fan is in good condition for maximum cooling. There may be debris build-up in the fins or the rad prescreen inhibiting air flow. My understanding from previous threads is that the normal fluid temperature is about 177° +/- for the liquid cooled tractors with an oil cooler in the rad. Work that is harder will, of course, raise the temperature of the coolant with a corresponding rise of the hydro fluid temperature. If the hydro is at 196°, you can be assured that the engine temperature is even higher.
Keep in mind that only the fluid from the 4.6 gpm auxiliary pump goes through the cooler. The hydro pump recirculates up to 3 times as much fluid and that is where most of the heat is made. High hydro pressure is what develops heat in quantity.
WOT will help keep the temperature in check with sustained heavy load work. That delivers max flow from the auxiliary pump to the oil cooler, and max engine coolant and air flow to the rad.
Click for The Hydraulics Forum!
Sometimes you get on a roll, sometimes the roll gets on you.
MF GC2310, Husqvarna YTH20B42T
Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.
Last edited by TUDOR; 06-10-2019 at 05:36 AM.