So I have a failed secondary air pump that I started removing today.

 

I disconnected the 2 air lines and a lot of water came out. I'm no expert, but water in an air pump probably isn't great.

 

I don't think there are obvious splits on the hoses so I'm wondering how it got so full of water?

 

Anyone know a good place for a cheap pump? Autodoc is quoting circa £140 and I don't trust the ebay ones as it when I put in my reg it says it won't fit!

Either drill out the rivets holding the 2 halves together and replace with nuts and bolts, or bypass it, plenty of threads on how to remove it and parts needed.

The part number is 078 906 601 M and genuine they are £863.57 🤑 When mine failed about five years ago I looked at buying a Pierburg but they were still £300 trade then (half that now) but I noticed Max Speeding rods were doing them for £25 (£27 now) and took a punt. It is still working now and is quieter than the original. The one on Mrs Crasher 3006 Polo GTi is getting noisy and I will fit a Pierburg on that as I am trying to keep it very original but £864 is taking the ****.

I'm also going to replace the sai valve aka combination valve as it seems this failing would likely be the cause of why the air pump is full of water. 

The valves were also the cause of poor initial running first start whilst the pump was running, I got mine from Pierburg.