power steering vacuum.?

Have problem with my power steering pump, when I take the cap off I have a lot of vacuum...should there be vacuum in the steering pump tank.??? about every two weeks I have to add a little fluid, I dont see any leaks. I bought a new pump today was going to change it but seem to be a big job, motor mount have to be remmoved.....any suggestions on the vacuum.???
Please help

the vacuum is caused by the fluid loss. as the fluid leaks out, the level drops, and when you pull the cap off, air rushes in

you might want to find the leak before going thru the hassle of changing the PS pump...

Have problem with my power steering pump, when I take the cap off I have a lot of vacuum...should there be vacuum in the steering pump tank.??? about every two weeks I have to add a little fluid, I dont see any leaks. I bought a new pump today was going to change it but seem to be a big job, motor mount have to be remmoved.....any suggestions on the vacuum.???
Please help
I dont see no leaks up top by the pump this weekend I will look under the car where the line run, maybe one of the lines...thanks

I found the leak it was the pressure line, reppalced the line but still have vaccum in the power steering tank. Any suggestions...Please Help

I found the leak it was the pressure line, reppalced the line but still have vaccum in the power steering tank. Any suggestions...Please Help
Any suggestions on other things to check......

some vacuum is normal, as long as your not losing fluid, don't worry about it.

some vacuum is normal, as long as your not losing fluid, don't worry about it. Im not losing any fluid just when I take off the cap I have a little vaccum.....I never had this before...Thanks...I will keep checking the level

like richtazz said if you're not losing fluid don't worry. It could be caused by something as quirky as when it heats up, the fluid expands and forces a little air out and when it cools down the fluid contracts but not enough to pull air back in, just making a slight vacuum.

like richtazz said if you're not losing fluid don't worry. It could be caused by something as quirky as when it heats up, the fluid expands and forces a little air out and when it cools down the fluid contracts but not enough to pull air back in, just making a slight vacuum.
Thank for the information :)