Ronski, thank you for your business and the nice call out. Our shock also uses a quad ring. Replace the backer ring when you change the seal and make sure everything is clean. Lube the quad ring well. Look closely at the old leaking quad ring. Look for nicks. Sometimes the rings can stick to the shaft and roll over, you can usually spot this as it will still be twisted in the groove ore the wear patten shows what happened. Take care with the source of the quad rings cause some non metric sizes are close but a little smaller than the actual metric size. Nicks, gouges or other tool marks in the groove WILL cause trouble.
Cogent Dynamics Inc.