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Discussion Starter · #1 ·
I'm currently experiencing a weird phenomenon with my power steering pump on my JDM 2003 Blobeye WRX STI.

Last month I did a complete rebuild of the pump, because it was leaking pretty badly. I disassembled it and put brand new o-rings in it, now it's not leaking anymore. After I installed the pump again and bled the system thoroughly, I noticed that from around 3500 rpms and up when stationary, I have just a minimal amount of steering angle until the pump seems to "cut out", and does not assist me at all while steering. I discovered this very randomly really, and have since then tested it the other day again, this time at around 5000 rpm with the same effect. As soon as the revs drop again, steering gets light again immediately and everything is fine again. The pump does not make any kind of strange noise etc. nor is there any air in the system.

I know that the power steering pumps on these cars have rpm dependent power steering assistance, as in higher engine rpm = less power steering assistance, to help keep the car stable at higher speeds. This is achieved through a flow piston construction inside the pump that opens accordingly in relation to pump speed (or engine rpm). So the effect I'm experiencing could somewhat be explained this way, however I've not noticed this behavior before the rebuild (but to be fair I also did not try what is shown in the video before...) of the pump and also it does seem to be quite severe.

I'll attach a video for you to take a look at what I mean.

Maybe someone with an STI and some time on his hands is willing to try to replicate what I'm doing in the video with his car and report back to me how it behaves? Worst case scenario would be a new pump from Japan, which obviously would be difficult to source and also pretty pricey, because they're different pumps than the EU/US pumps...


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