Tue Apr 22, 2014 10:01 pm
No, they are basically a pain in the rear to get in. All I use is a blunt rod like a wooden Qtip. That particular oring needs to be lubricated, a little more than most do.
Unfortunately not on most regs including this one. As a general rule the higher the differential pressure across the oring the higher durometer it needs to be. 90s (harder) for most high pressure use and 70s (softer) for lower/IP use. I rebuilt a 950 a while back and I used 90 durometer 006s (size number)for that application, odds are the 400 uses the same size. To determine size, a good digital caliper or micrometer and a oring chart are the best ways to determine what an unknown oring is. Most you can tell guess if it's a harder (90) or softer (70) by squeezing it between your fingers....it's best if you have a known durometer one of roughly the same size to compair it with.
Herman