Which vacuum lines do people replace?

[Davyhay]

I hear about the brittle vacuum lines on our cars, but I am trying to figure out which lines I should be looking at. The only vacuum line that is obvious is the one splitting to the blowoff valves.

[BrewRifle]

All three of the lines running off of that Y connector can be replaced. Be careful when taking the single line from the right side near the throttle body as the nipple can break easily (ask me how I know).

[Davyhay]

So one line from throttle body to y adapter and the two from the Y adapter to the blowoff/diverter valves? Is that it?

[Davyhay]

Just trying to get all the info I can--tomorrow is going to be a DIY service day for the Bimmer.

[e36addict]

The more common ones are on the opposite side of the engine... the hot side. Lines go from vacuum source near vacuum pump (behind oil filter housing), over the valve cover and to the bottom of the vacuum reservoirs. Then from the top of the reservoirs to the wastegate control valves, and from there to the wastegates themselves. It's a bit of a job, and it's quite a bit of vacuum hose.

[135Pats]

The vac lines running down the hot side are a pain in the ass, just a heads up.

[stevenc]

my car is in the shop right now for hot side vacuum lines.