The brake cooling system for the tractor utilizes oil from the transmission. The oil is cooled and filtered via the transmission oil cooling system. The oil is then circulated around the front brakes via a gear pump located on the transfer case.
(1) Transmission oil filter
(2) Brake cooling pump
(3) Transfer case
(4) Line to the brakes
The brake cooling pump (2) services the front brakes only. The brake cooling pump is located on the transmission on the rear of the tractor. The brake cooling pump is run off the transmission and constantly circulates oil though the two front brake housings. The oil flows out of pump (2) and into the front brake housings through hose (1). The oil then flows from the brake housing (4) to transmission. The cooling oil is part of the transmission oil system and will be cooled by the transmission oil cooler. The brake cooling oil is filtered through the transmission oil filter (9). Refer to Illustration.3 for a picture.
Oil Filter (Brake Cooling Oil)
The brake cooling oil filter is mounted on the right side of the machine frame under the platform. This filter is used to filter the power train oil.
(1) Transmission oil filter
(2) Oil flow from transmission pump
(3) Transmission oil filter bypass valve and switch
(4) Oil flow to transmission control valve
(5) Transmission ECM
The brake cooling oil filter (1) is mounted on the right side of the machine frame under the platform. This filter is used to filter the power train oil.
The brake cooling oil filter is an externally mounted oil filter (1) that has a bypass valve. Restriction in the oil filter or if the oil viscosity is high, will cause bypass valve (3) to open. A block of the filter can result in a greater hydraulic oil temperature than the limit programmed into the ECM for each component.
The pressure switch (3) contains a plunger that closes the contacts with an acceptable pressure drop across the filter. The pressure switch grounds the signal circuit during normal operation. The plunger of the pressure switch moves to allow the pressure switch contacts to close. The pressure switch contacts open when pressure across the filter is greater than the specified value. If the filter is restricted the open pressure switch sends a signal to the Transmission/Chassis ECM. The ECM informs the operator that the filter is restricted or dirty. With a maximum PSI is present, the switch will remain closed. When the PSI is at a minimum, the switch is open. The circuit for the switch is normally closed. The bypass valve opens to protect the system if the filter is restricted. The bypass switch provides an input signal to the Transmission/Chassis ECM. The Transmission/Chassis ECM determines if the filter is restricted. The status of the system can be observed by use of the Cat ET program.
If the inlet pressure to the oil filter is greater than the outlet pressure, the bypass valve will open. When the oil does not flow through the filter element, the debris in the oil could damage other components in the hydraulic system.
Correct maintenance recommendations must be followed in order to ensure that the element does not fill with debris. If the element is full of debris, the flow of clean oil to the hydraulic system stops.
View of the transmission and brake cooling oil cooler.|
The brake cooling oil for the tractor is shared with the transmission. For information regarding the flow of the transmission oil see the Power Train portion of this book.