IMHO, a small hole drilled through from the pump exterior to intersect the relief piston bore just ahead of the piston at full retraction will add to relief volume (and reduce overpressure), it just won't be recirculated. This is probably not true with all pumps, but my subject pump has a .420" relief piston (.138" area), but the relief port is only 11/32" diameter (.093" area), and only bypasses 67% of the possible volume. A single 7/32" hole to the exterior will only open when the piston is fully retracted and will not affect normal operation. This brings the total bypass dump area up to .130", almost the same area as the valve itself.
No, I haven't tried it yet.
Anyone see anything that's going to bite me?
To be honest I think that would work well... I dont
foresee any issue because it would only open that
port at or right near max open... which in case would
help dump the aerated oil
