Originally Posted by
GenX69
I changed the shock oil for the first time on the front shocks. I think I've put 12 or so packs through the car so far so felt it was time. Plus I wanted to check to make sure there were no issues. The caps were dirty on the inside and the bladders had dirt on top of them. I fully expected the oil to be dirty as well. However, the oil was still clean. The dirt must have gotten in via the bleeder hole on the caps and then collected above the bladders.
There is a pin-sized hole on the inside of the caps. It is right in the center. Does that serve a purpose?
It's a vent to keep the shock more consistent. You can put some glue in there to cover it up and it will act like a normal cap. The vents make it easier to get zero rebound in the shocks and make them more consistent but not necessarily 'better' for every track condition though. A 'bleeder' cap (just the side hole) will have more rebound since the air above the bladder doesn't have anywhere to go.