HYDRAULIC PRESSURE TEST

An accurate tachometer and pressure test gauges are required. Oil Pressure Gauge C-3293-SP has a 300 psi range and is used at all locations where pressures exceed 100 psi.


Pressure Test Port Locations



Only two pressure ports are supplied on the transmission case. The torque converter clutch apply (3) and release (1) ports are located on the right side of the transmission case.



To determine the line pressure, there are two available methods. The scan tool can be used to read line pressure from the line pressure sensor. The second method is to install Line Pressure Adapter 8259 (3) into the transmission case and then install the pressure gauge and the original sensor (2) into the adapter. This will allow a comparison of the scan tool readings and the gauge reading to determine the accuracy of the line pressure sensor. The scan tool line pressure reading should match the gauge reading within +/-10 psi.



In order to access any other pressure tap locations, the transmission oil pan must be removed, the pressure port plugs removed and Valve Body Pressure Tap Adapter 8258-A (2) installed. The extensions supplied with Adapter 8258-A will allow the installation of pressure gauges to the valve body.



Refer to the Pressure Tap Locations graphic for correct pressure tap location identification.


TEST PROCEDURE

All pressure readings should be taken with the transmission fluid level full, transmission oil at the normal operating temperature, and the engine at 1500 rpm. Check the transmission for proper operation in each gear position that is in question or if a specific element is in question, check the pressure readings in at least two gear positions that employ that element. Refer to the Hydraulic Schematics at the rear of this section to determine the correct pressures for each element in a given gear position.

NOTE: The 45RFE/545RFE utilizes closed loop control of pump line pressure. The pressure readings may therefore vary greatly but should always follow line pressure.

Some common pressures that can be measured to evaluate pump and clutch performance are the upshift/downshift pressures, garage shift pressures, and TCC pressure. The upshift/downshift pressure for all shifts are shown in UPSHIFT PRESSURES and DOWNSHIFT PRESSURES. In-gear maximum pressure for each gear position is shown in IN-GEAR PRESSURES. The garage shift pressure when performing a N-R shift is 220 psi. The garage shift pressure for the R-N shift is 120 psi. The garage shift pressure for the N-1 shift is 135 psi. Torque converter lock-up pressure is 120 psi.


UPSHIFT PRESSURES

1-2
2-3
2prime-3
3-4
2prime-4
2-5
3-5
4-5
120
120
120
120
120
120
120
130


DOWNSHIFT PRESSURES

5-4
5-3
5-2
4-3
4-2prime
3-2
3-2prime
2prime-1
2-1
3-1
120
120
120
120
120
120
120
120
120
120


IN-GEAR PRESSURES

1
2
2prime
3
4
5
NEUTRAL
REVERSE
135
120
120
120
120
120
120
220