mako ka-7da, reval 5404 block 3rd stage releif valve popping

[bartman27]

I love this Board, its where i come to cry whenI have compressor issues lol - my 5cfm 5000psi unit was having issues getting over 3500 psi for the past 2 months or so, even with the outflow line deadended, the pressure was taking much longer than usual to climb to 4000psi - Now the 3rd head pressure relief valve has started to pop off as the unit is running - the 3rd stage valve were replaced about 100 hours ago - any ideas what the issue could be - i had been thinking about rebuilding the third stage including piston and rings but the post about cracking rings has me scared - any ideas about how much a rebuild/repair on the 3rd stage could cost me? thanxs - I am learning
bm

[Zodiacdiverdave]

I would have another look at the third stage valve again and while you are at it check the other valves as well. In the old days we would clean the carbon off the valve and if there was no damage to the springs re-install them to get a bit more time from them. But if you cannot afford down time them replace the parts to the valves with new pieces.
You could also check the relief valve cracking pressure to ensure it is still set properly.
ZDD

[bartman27]

thanxs - its being addressed right now - my guess is that the third stage piston needs to be replaced as i was having to add oil to the block frequently. I have never pull the head off any of the stages. How critical is it when replacing the head with the new valve to torque the bolts. Is there a sequence to installing the hex bolts as well? or am i making more of it than there needs to be - i have worked on pump heads before but that was liquid filled - we will see

thanks
bm

[Wookie]

Buy a torque wrench. It's an oring seal, proper torque is just shy of critical. Standard 6 bolt flange torque pattern is fine. Torque in 3 steps. That third stage safety could be why you're using oil and taking longer to build pressure than normal. Check the ports with snoop or 409 and make sure it isn't seeping.