VW MK5 Golf GTi TFSI Brake Booster Hose 1K0 612 041 GM Information

This is just a short post to help anyone else out and save them doing the research I had to.

The brake booster hose connects directly to the vacuum pump as part of the system to give power assisted braking. There is also a check valve which prevents boost from going into the vacuum pump.

Over time the hoses can become brittle and start to crack around the connections, the plastic check valve also becomes brittle and can be easily damaged when working on the car.

Failures of this part can result in several symptoms:

  • Loss of power braking assist
  • Check valve failing to close resulting in loss of boost pressure
  • Idle and vacuum issues

Side note: The short rubber hose between the check valve and the inlet is a popular place to take a boost tap from to operate a boost gauge or vacuum operated diverter valves such as the Forge Recirculating Valve (FMFSITVR ).

VW part numbers:
  • Original part number: 1K0 612 041 BM (shown below without extra vacuum nipple)
  • Superseded part number: 1K0 612 041 CH (also without extra vacuum nipple
1K0612041BM brake vacuum hose
1K0612041BM brake vacuum hose
  • Latest part number: 1K0 612 041 GM (as shown below with extra vacuum nipple)
If you car does not have a pipe for the vacuum nipple (e.g. AXX) then you can just block this off, the genuine part number for this is 056 129 777 which looks like a mini green traffic cone.
1K0 612 041 GM latest part number. Photo owned by ECSTuning.com


  1. Good article, wish I'd read it before I had to learn the hard way. Don't forget to block off the nipple or you'll create a vacuum leak when going from BM to GM.