The Silver S4 I have worked on has the Brake Booster hose arrangement that joins the Accordion Hose, Intake Manifold, and Brake Booster by a 3-way junction.
The new intake setup consists of the 034 silicone hose to replace the stock accordion hose thus doing away with the grommet that allows for the connection to the accordion hose. Like most places inside the engine compartment space is tight around where this hose is located so that leaving capped off parts is undesirable, as well as a potential source for leaks.
I set about modifying the hose to run direct from the intake manifold to the brake booster connection at the firewall.
Using a knife I removed the connecter that attaches one end of the stock line to the intake manifold, intending to reuse this part. The stock part that connects the line to the brake booster is not a check valve, but one is needed so that boost does not reach the Brake Booster.
The connector that goes to the Accordion Hose is a check valve and it could be re-used, but in this case the car has 150k miles on it and I prefer to put a new check valve in place.
The other part needed for this job is some hose. I felt the best option was this stuff as it consists of an interior rubber lining, a metal mesh wrap, and a fabric covering. Air tight and strong to withstand vacuum.
The part numbers are:
- Brake Booster Check Valve –191611933F (Comes up as a part for a Porsche)
- Brake Booster Hose – N0203901
The check valve goes in one end of the hose, to attach to the firewall, and the other has the connector for the intake manifold.