When I purchased my 07 audi a4 with the 2.0t the previous owner had taken the car to a mechanic to have them find out why it smells of gas during cold weather. They supposedly fixed it, but I still smelled gas, after doing some research and looking around under the hood, I found the problem. The mechanic replaced a rubber fuel line going into, what i think is, the fuel pump, which also happens to be what you remove to check the cam follower. This is the link that helped me out a lot, SIMPLE DIY cam follower check. DUMMY PROOF - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com
although I know thats a gti and I have an a4 I believe its the same motor, or at least really close to the same.
Anyway, when I was trying to get this fuel line out
I broke this plastic hose

Now in my ignorance I also took the fuel pump (at least thats what i think its called) apart

can I put that back together and have it work properly, or do I have to replace the whole thing?
And since I am here, how do I know if my cam follower needs to be replaced?

 

Though I can't tell you what that hose is by your picture, I can tell you that since you have the cam follower exposed, first inspect it to see if it is worn quite a bit. But if it was me, I'd anty up the $60 for a new one and put it in there....peace of mind knowing it's new and you wont have to take the fuel pump off again or worry about it for another 20,000 miles.

I'd have to look at my own engine to determine what that hose could potentially be. Or maybe someone will chime in. As for the fuel pump, not sure why you took it apart but put it back together and slap it back in the hole. Also if there were any gaskets or o rings that you took off it, might want to replace them as a precaution. Once it's all back together be sure to prime the pump a bit by turning the ignition on and off 3 times or so without starting the engine, then once you've done that, go ahead and try to start it (providing you get that hose fixed first). I'll check my engine today when I get home from work if I can remember to and try to help you further.

 

Thanks man, I replaced the broke plastic hose, and the rubber fuel line. I had to take apart the fuel pump to be able to take it off, and replace the rubber fuel line. and do you happen to know what the fuel pressure in supposed to be so I can test to make sure I put it all back together correctly.

 

I don't know the fuel pressure but it should be higher than 40 or 50 I would think. may need to do some checking on the internet or give the dealer a call and ask.

 

You have both a low and high pressure fuel system.The low pressure should be about 72psi.
The high pressure systems maintains a range between 725-1595 psi.

If you do any work yourself,Go to Amazon and buy yourself either the Bentley CD or Service Manual.It will be the best $95 you'll spend!