2005 Eddie Bauer Booster Check Valve

[kylejw]

Hey All,

I have a 2005 Eddie Bauer with AdvanceTrac

My issue is very weak braking power when first pushing the pedal. If I leave my foot on it for a second and push further, it grabs nicely. Pedal is very firm with engine off so I believe this to be a vacuum issue.

I'm seeing no vacuum from the intake port at idle (I think this is normal)
I see 19 inches from the manifold (at 3000 ft elevation so it's probably more than that)

However I noticed that the manifold vacuum is sucking all the way through the booster check valve and into the intake. I think this is bad, because all my vacuum is presumably sucking from the intake instead of the booster! Essentialy, air flows between the two yellow ports on the check valve.

Anyway I wanted to confirm how this 3 hose check valve is supposed to work? And is there anywhere I can buy one? The dealer said they aren't available from ford but he gave me a part number that looks totally different - 5L1Z-2365-A

Thanks

 

[kylejw]

So the check valve in this case is called an aspirator and it looks like it follows the design here:

US20150337867A1 - Brake vacuum aspirator - Google Patents

A brake vacuum aspirator has a generally known construction and function and includes an optimized bypass flow path including an optimized check valve making the brake vacuum aspirator capable of a performance level not previously obtainable in brake vacuum aspirators. In particular, the brake...

patents.google.com

One the venturi effect gets involved, Id normally head for the hills . But I'm going to keep testing here.

 

[kylejw]

I stumbled on this video too talking about 2011-2012 EcoBoost and it sounds like Ford ended up ditching the aspirator bit?

2011-2012 Ford F-150 3.5L Ecoboost Hard Brake Pedal: Electric Brake Vacuum Pump Replacement

In this video we show you how to replace your electric brake vacuum pump with the latest Ford part. This fixes ABS DTC C109D and a hard brake pedal upon firs...

youtu.be

These have a vacuum pump too though to supplement

 

[Ken0356]

I have same issue with my 2006 XLT Expedition. Were you able to locate a replacement aspirator valve?