Hey guys and gals,
I just finished replacing all rotors and brake pad and I noticed a vacuum line connected to the rear brake pad manifold bolted on the rear axle. The manifold has 3 connects (2 hard brake [driver/passenger] lines +1 Vacuum line) and the vac line was not connected to anything and was zip tied to the driver side rear caliper bracket.

Does anyone know what this is?

I have a 2005 f150 king ranch 2wd.

 

that is actually the vent for your axle. It allows air to escape when the fluid heats up and expands.

it should be up out of harms way, to keep from sucking water into the differential


factory usually has them clipped onto the underside of the bed on a support bar

 

Just run it up to the frame someplace and make sure the tip is turned down.

 

Thanks for the info, I am little confused as to how the axle is vented through a brake fluid manifold, am I missing something?

 

essentially its just a tube that goes through the brake bracket into the axle

 

The tee fitting for the brake lines (1 soft line in, 2 hard lines out) is held in place attached to the axle housing by a long fitting for the vent itself and the hole through which the vent fitting passes is closed off from the passageways which distribute brake fluid. There is no way for brake fluid to mix with axle lube or vicey-versa.

It's the same on my '77 as on my '07. I would not be surprised if the same set up hasn't been uised for over 50 years.

 

wow thanks for sharing the info!

 

One of the few times where engineers didn't overthink it and heeded to the old saying "If it ain't broke, don't fix it."