I noticed Lowe's has a ticker #78 o ring did you try them ?
- Yes, they are too big. I also tried a #36, which is very, very close to the right size but still, too big.
Since you are repairing every 6 weeks or so where are you getting the o rings ?
- The repair kit Sun Optics sent me came with 6 o-rings. I am down to only two left. I have not found a source for good replacements yet.
Are you replacing all the o rings every time or just P30 ?
- No, the other o-rings are holding up just fine. It is only P30. I've replaced it so much that I can do it in about 15 minutes now.
Did the 10w 40 motor oil seem to work better then the silicon grease that was in it originally ?
- I have not tried using this on the whole pump, just the P30 O-ring and unfortunately, it doesn't make much of a difference.
Do you think full synthetic motor oil would be better ?
- It actually might, at my next replacement I'm going to try that.
I'm actually in the same boat with you Bruce. My gun shoots amazingly, 1/2 inch groups at 45 yards and sub 1/4 at 20 yards. The pump is definitely the weak link but it can be repaired very quickly once you master disassembling it. And my 6 week repair schedule is a rough average, I shoot a lot, sometimes filling my Marauder from 2100 psi back to 3000 psi 3 - 6 times a day on weekends and at least 3 more times throughout the week. So my pump may get quite a bit more use than say your average shooter's. I'm looking into buying higher quality Viton orings or better, I'll post back with the exact sizes for the P30 oring. Got to get new batteries in my calipers.