How to change primer valve o-rings
- 1. HOW TO CHANGE THE PRIMER VALVE O-RINGS STEP 1 When performing any inspection or maintenance on the powerplant, propeller or that requires turning on the master switch, or pulling the propeller through by hand; treat the propeller as if the ignition switch were on. DO NOT stand, nor allow anyone else to stand, within the arc of the propeller as a loose or broken wire or component malfunction could cause the propeller to rotate.
- 2. STEP 2 Turn selector valve OFF.
- 3. STEP 3 Unlock and pull primer plunger 1/2 way out.
- 4. STEP 4 Hold backside of valve assembly and loosen knurled nut on frontside of valve. BE CAREFUL to not twist or bend small copper lines on backside of valve.
- 5. STEP 5 Slide nut 1/2 way down plunger and place a cloth under the plunger. Remove plunger from the frontside of the valve. A small amount of fuel will drip out of the plunger cavity.
- 6. STEP 6 Once plunger is out, clean the plunger and remove the o-rings on the end of the plunger.
- 7. STEP 7 Install the correct fuel resistance o-rings. See “ Fuel Injection and Primer System Parts ” under Aircraft Parts By Category on our website to purchase the Primer Seal Kit which includes two MS29513-012 O-Rings and one lube capsule. Lubricate the o-rings and plunger.
- 8. STEP 8 Reinstall the plunger and tighten the knurled nut.
- 9. STEP 9 Turn ON the fuel selector valve. Exercise the primer two or three times to fill the plunger cavity with fuel. Check for leaks around the knurled nut.
- 10. PRIMER VALVE O-RINGS INSTALLATION COMPLETE Make appropriate logbook entry of the work performed. The FAA has a sample logbook entry shown in the free video on our home page at www.apex- inc .biz . This presentation contains information that is consistent with FAR 65.83 “Recent Experience Requirements.” Please visit www.apex- inc .biz to view a free video that reviews Basic Maintenance for Pilots and Technicians as part of FAR 43 and 91. Click on “Watch the video” located about half way down on the left side of the page.