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View Full Version : MKV Brake Booster Question



Tango
08-24-2025, 09:08 PM
The main Question: I do not see any reference in the instructions for hooking up the brake booster to a vacuum line. How would one go about doing that with a gen4x coyote?

The longer story:
I logged my first .7 miles today….with a passenger, to the nearest stop sign and back…waving at a few inquisitive neighbors. Everything was really good. Then the brake pedal felt a little soft. I have read and re-read the instructions for the new booster and I see no reference to hooking it to a vacuumed feed but surly you need to, how else would it work? I am left wondering if I missed something or is there a significant step missed in the install manual that makes the magic happen.

Any guidance would be appreciated.

Dgc333
08-25-2025, 06:11 AM
Absolutely needs a vacuum source. Just hook it to a convenient port on the intake manifold, use a tee if necessary.

Reddrig
08-25-2025, 06:14 AM
There is a plastic piece with a covered Vacum port middle of the booster, run a Vacum line to the booster and your good to go. This is providing you have your front and rear brake circuit hooked up correctly. You can run Vacum from the engine, dealers choice on where you want to pull from.

Blitzboy54
08-25-2025, 06:39 AM
The intake manifold of a coyote has several unused vacuum ports. Plumb it to one of those.