Accordion to Brake Booster Modification

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.

Accordion to Brake Booster Lines
Accordion to Brake Booster Lines

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.

Brake Booster Check Valves
Brake Booster Check Valves

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.

Brake Booster Hose
Brake Booster Hose

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.

Brake Booster Check Valve
Brake Booster Check Valve

4 thoughts on “Accordion to Brake Booster Modification”

  1. The hose is not soft, it has a wire mesh integrated on the outer portion that is then covered in fabric. I had to use a Dremel cutoff wheel in order to cut to the desired length.

  2. Very timely Jeff! And well done. I’ve a silicone hose on the way and knew I would have to deal with this!

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