Things I liked: Spare set of orings. Nice.
Things I would have changed: Needlessly expensive.
What others should know: Nice that the manufacturer offers parts like this.
Things I liked: Nice to have on hand if you need to repair your pump.
Things I would have changed: Nothing.
What others should know: Keeps you shooting rather than waiting on parts to make a repair.
Things I liked: Hills are very good pumps. But this rebuild kit is oversell. They make you buy a lot of parts you will never use.
Things I would have changed: Just sell packs of the little green o-ring.
What others should know: All makes of pumps will need rebuilt from time to time. In all pumps it is the same o-ring that breaks down. The sad part being, you can get a Benjamin or Air Force pump and if the seals go out you can call Sun Optics and they will send you the parts for free.
Will this kit work with the new MK4 pump?
No, you need to buy Hill MK4 Hand Pump Complete... for it.