TM 9-2320-209-10-1 e. Checking Condition of Filter. Filter should be checked as follows once a day during pumping operation. FRAME 1 1. Start engine. (Refer to para 4-6b. ) 2. Transfer power to the pump. (Refer to para 4-9d, frame 2 for procedures). 3. Open rear compartment doors and hook up ground wires. (Refer to para 4-9d, frame 3 for procedures). 4. Take a pressure reading on inlet side of filter. (a) Turn pressure gage control handle (1) right, to position NO. 1. (b) Write reading down. GO TO FRAME 2 4-139