The atmospheric pressure sensor (1) is installed on the hydraulic supply pump group adapter and is vented to the atmosphere. A foam block below the sensor helps prevent the entry of dirt into the sensor. The sensor performs the following functions: Ambient pressure measurement for automatic altitude compensation and automatic air filter compensation. Absolute pressure […]
Category: Bulldozer
HEUI Hydraulic pump components
The pump control valve (1), also referred to as the “injection actuation pressure control valve,” controls the angle of the pump swashplate which varies the pump oil flow. Also mounted on the hydraulic supply pump group is the hydraulic temperature sensor (2). This sensor is used by the ECM for viscosity compensation to maintain consistent […]
HEUI system components
The principal component in the HEUI system, the Electronic Control Module (ECM, 1), is mounted on top of the right front valve cover. The ECM is the “heart” of the engine. The ECM performs engine governing, timing and fuel limiting. It also reads sensors and transmits data to the instrument display system through the CAT […]
3408E/3412E HEUI FUEL SYSTEM
The electronic components in the HEUI fuel system are very similar to those used in other EUI systems. However, in the HEUI system, the injectors are not actuated by a camshaft. A high pressure hydraulic pump, which draws oil from the pressure side of the lubrication pump, raises the pressure to a maximum of 22800 […]
HEUI fuel system components
The water separator (1), which also functions as a primary fuel filter, is an important part of the fuel system. As with any high pressure fuel system with operating pressures at approximately 150000 kPa (22000 psi), fuel quality is important. Water in the fuel can cause corrosion of the plungers and barrels. Dirt can cause […]
3408E Engine D9R
The HEUI system has many features and benefits not possible with mechanical fuel systems. These features include a very clean exhaust, improved fuel consumption and cold starting, simplified maintenance with fewer moving parts, and reduced operating costs. The HEUI system eliminates many of the mechanical components of a “pump and line” system. It also provides […]
Left side of machine D9R
The primary fuel filter (1) and the secondary fuel filter (2) are located on the left side of the machine behind an access door. Also located in the compartment are the fuel hand primer pump (3), the fuel shutoff (4) from the tank, the windshield wiper fluid reservoir and individual washer pumps (5) which are […]
3408 Engine D9R
The air supply to the 3408 Engine flows through a “bonnet-type” inlet screen (1), which is mounted on the hood. A daily inspection of the inlet screen is important to ensure that dirt or other material does not clog the screen and restrict the flow of air to the engine. Also, a tubular-type precleaner is […]
Air conditioner components D9R
For machines equipped with an optional air conditioning system, the compressor (1) is located in the front of the engine compartment. The compressor is driven by a belt which is connected to a pulley on the front of the engine. The compressor is used to change the refrigerant from a low pressure, low temperature vapor […]
Crankcase oil drain D9R
Access to the drain plug for the crankcase oil is provided by removing the crankcase drain access cover. The D9R utilizes an “ecology-type” drain valve to help prevent spills or oil loss when the system is drained. To drain the oil, remove the plug (1) and then turn the valve (2). The valve can be […]