CORE AS-AFTERCOOLER 3354189 - Caterpillar

Illustration 1 g02020570
Typical view
Personal injury or death can result from sudden machine movement.Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine.To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Note: Prior to performing this test, perform the test in Testing and Adjusting, "Brake System Pressure - Test and Adjust". This test will check the parking brake pressure at the rear test ports when the machine is shifted into gear.
Start the engine. Allow the brake accumulators to charge fully.
Run the engine at low idle. The pressure in the brake accumulators will decrease because of leakage in the system and lubrication. The solenoid valve controls the charge cycle for the brake accumulators. Allow the charge cycle for the brake accumulators to occur at least ten times before any measurements are made. Note: Note the pressure at the cut-in pressure and at the cutout pressure.
All of the conditions that are listed below must be met before the test can be performed:
The wheels must be chocked.
The transmission must be in the PARK position.
The engine needs to run at low idle.
The position lever for the body must be in the HOLD position.Note: The test can start when all of the conditions that are above are met.Note: Read the next step completely before performing any corrective action.
In one steady motion, while the engine is running at a low idle, fully apply the service brakes and shift the transmission into gear.
After 30 seconds, shift the transmission lever into the PARK position.
Before the brake system starts to recover the pressure, locate the lowest pressure that was reached. Also, check the time that was needed to recharge the accumulators or the cut-in to the cutout pressure. The time that is required for the accumulator to recover should not be longer than 12 seconds. The probable causes for long recovery times are a solenoid valve (unloader) or the diverter valve (unloader) is failing or system leakage. The pump may also be failing. The lowest pressure of the brake system should be 9500 kPa (1380 psi). A low brake system pressure could mean a solenoid valve (unloader) or a diverter valve (unloader) that is failing, internal leaking of the control valve (brake), or the drain back through the parking brake release pump.
Stop the engine. Note: Perform the Testing and Adjusting, "Slack Adjuster - Test and Adjust" in order to determine the pressure at each wheel.