P/S overflowing only when driving

[sick_s14]

1995 S14 w/Rb25
Early gen chase bays powersteering kit
Rebuilt rack due to leaks

Got an issue that ive been dealing with ever since I rebuilt my rack about a month ago. After rebuilding my rack, when driving fluid pushes out of the vent on the cap. Yes, the level is correct. No, there are not any leaks. I have turned the wheel back and forth probably 30 times to make sure there was no air in the system. When idling, the fluid in the reservoir is not excessively fast flowing. No odd noises from pump. I am having trouble pinpointing this issue and I was wondering if anyone had some input or ideas? Anything would help!

Thanks!

[AZhitman]

Dumb question, but are you certain you don't have the feed and return lines reversed?