Table 5-3. Direct and General Support Maintenance Troubleshooting (Continued)
TEST OR INSPECTION
FORMULATION TANK WILL NOT HOLD PRESSURE
Determine if the problem is in the formulation tank or the compressor.
BE SURE the formulation tank is empty of any liquid before testing it.
BE SURE to turn the solenoid valve switch OFF before pressurizing the formulation tank.
BE SURE there are no personnel in front of the nozzle before starting the engine.
DO NOT walk in front of the nozzle when the engine is running.
Turn the solenoid valve switch OFF and start the engine.
Check the control panel pressure gage.
If the pressure is 90-100 psi, the compressor is ok. Go to Step 1c.
If the pressure is less than 90 psi, go to Page 5-171 symptom 12.
When the tank pressure reaches 11-14 psi, shut the engine OFF and go to Step 2.
Check all fittings and joints for air leaks. See figure for fitting and joint locations.
Listen for air leaks.
If they can be located, correct them and then go to Step 2d.
If there are no apparent leaks, go to Step 2b.
If the safety valve opens before the tank pressure reaches 11-14 psi, go to Step 3.
Test the fittings and joints for air leaks.
Prepare a thick lather with soap and water.
Spread the lather around all the fittings and joints in figure 1.
If there is a leak, it will blow bubbles through the lather. Go to Step 2c.
If there are no leaks, go to Step 3.
If the filler cap leaks, go to Step 4.