power steering

I replaced the power steering pump a month ago and it seems that i am getting to much pressure as fluid is being forced out of the top of the tank. the cap is good and it appears that the spring in the cap is also good.What could cause to much pressure to force the fluid out of the tank?Its almost impossible to monitor the tank because of where GM located it.

When you replaced the power steering pump was the system properly bled of possible air? What brand pump was installed? OEM or aftermarket? How is the fluid level (overfilled) and is the seal on the cap good? When power steering fluid heats up it expands.

I used some after market pump.Today i bled the air they way i was told on the other impala site. I did get quite a few air bubbles.I think that the air may have been the problem (time will tell). The seal on the cap looks good.