MCS and LCS PRIMING PUMP Instruction

Perform priming pump procedure as follows when you turn on the MCS or LSC during Installation, Replacement, or PM to prevent from damage of pump section of the MCS or LCS.

Priming Pump

It is critical to ensure the coolant has filled the pump housing before starting the pump.

  1. Confirm that all hoses are connected as described in Service Methods.

  2. Fill the reservoir. Check the float in the reservoir sight tube on the front of the unit to see the coolant level in the tank as you are filling. Fill the coolant so that the float reaches near the upper limit. Then, close the cap of the reservoir.

    Figure 1. FILL COOLANT

    Notice Image
    • notice
    • IF PUMP AND FAN MOTORS START, IMMEDIATELY DISCONNECT POWER.
    • RUNNING THE SYSTEM DRY FOR EVEN A SHORT TIME WILL DAMAGE THE PUMP!

  3. It is time to apply power and to quickly "jog" the pump "ON-and-OFF". The pump should be turned on for less than 1 second each time.The fan will also turn "on-and-off" simultaneously. This is normal. We are now "priming" the pump. Continue to do this several times, while watching the air from the system hoses purge back to the reservoir. If the coolant level drops half way between the top and bottom of the site tube, turn off the system and fill the reservoir.

  4. Repeat this ‘jogging’ and refilling process until the system is totally full and coolant begins to return back into the reservoir. This will be confirmed when the decrease in coolant level stops. The coolant level will eventually become stable when all the liquid passages have become full, and as much coolant is being pumped out of the reservoir as being returned to it. The reason for the slow filling procedure is to prime the pump and slowly push the air out of the system, back into the reservoir and out the filler opening. The slower the better, so that the pump seal is not damaged and air won’t become entrained in the coolant causing it to become ‘frothy’.