I ful the oil so much that it is level with the edge. If you fill it is possible to make the oil stand higher then the edge due to surface friction and then it will be too full to compress.
Thanks for the input. Where is the piston when you fill it so it's level? Is it extended all the way out, in the middle, or fully compressed?
I was looking in the ECX manual last night and it says a couple of interesting things. First, it says the piston should be in the middle when you put the cap on. It also says that when you're done, the piston should rebound by 3/8 inches (9.5mm) after being fully compressed.
When I put the piston in the middle and fill the shock to the top, I get full shock compression, but it rebounds more than the manual says -- about double that.
I ended up tinkering with it (basically putting the piston in different positions while filling it) until I was able to get about 3/8 inches (9.5mm) of rebound. Of course, when it rebounds only that minimal amount, the drastic improvement in the shock feel with new oil isn't so drastic.
Anyway, I feel like I'm out in a sea of uncertainty. I mean, I'm not racing and this is just an inexpensive RC so one might say, "Who cares?", but I just wish I knew exactly the correct way to do this. I'm a detail guy. I yearn for step-by-step instructions that produce consistent results! hahahahaha.
ECX: 3x Ruckuses (modded 39XXkv brushless), 1x Torment (stock)
Axial: SCX-10 Dingo Kit w/ Novak power (Eiger ESC + 35T Terra Claw motor)
Losi: 3x brushless Micro SCTs, 3x Micro 4x4 Trail Trekkers, 3x Micro Raminators
HPI: 3x Wheely King 4x4s (custom 4 link setups, lengthened, Monster Jam bodies)