2017 Expedition Limited - Brake Issue

[RC32]

Hi all! Thanks for having me here. So I have a 2017 Expedition Limited that recently lost it's brakes as my wife was pulling in to the neighborhood (luckily not on a highway but still scared the crap out of her). Some research and troubleshooting found that there is an issue with this year range for the master cylinder failing and leaking all the fluid in to the booster. I pulled the vac line off the booster and discovered there was indeed fluid in the booster. More research and I found that there is actually a recall on this for my year range. However, a call to my local dealer and to Ford revealed my VIN is not included! Frustrating since you would think they want to know about this issue happening to other VIN's, but they did not seem to care. So I replaced the master cylinder and booster myself (booster was full of fluid), bled the brakes, and now it seems to be working fine. However, I now have the little wrench icon showing up and the code is C109D-20 "low vacuum condition detected". But, as mentioned, brakes feel fine, engine is smooth, no issues. I pulled the switch out of the booster after a night of sitting and it was definitely still holding a vacuum, so I don't think there are leaks at the seals or in the lines. I was thinking the sensor right there at the booster went bad? I was going to try it, it's only $30 from the dealer, but figured I'd ask here first and see if anyone else has had this issue or had any ideas? Thanks in advance!

Ryan.

 

[RC32]

Good afternoon all! Just to add an update to this as I'm messing with it today, the light does not seem to come on while idling in the driveway. Even when pressing the brake several times and bringing the revs up a bit, I get get it to come on in park. As soon as I pull out and start to drive down the street, the light comes on. Everything still feels normal and it seems to be holdoing vacuum for hours after shut down. Really stumped here. IO keep coming back to the sensor but why would it not come on in the driveway? Any thoughts would be greatly appreciated! Thanks

 

[99WhiteC5Coupe]

Good afternoon all! Just to add an update to this as I'm messing with it today, the light does not seem to come on while idling in the driveway. Even when pressing the brake several times and bringing the revs up a bit, I get get it to come on in park. As soon as I pull out and start to drive down the street, the light comes on. Everything still feels normal and it seems to be holdoing vacuum for hours after shut down. Really stumped here. IO keep coming back to the sensor but why would it not come on in the driveway? Any thoughts would be greatly appreciated! Thanks

Did you bleed the ABS controller using a computer, which operatives the controller shuttle valves, and purges any air in the unit?

 

[RC32]

Thanks for the response sir. I did not. You said using a computer, I assume you need a special program and OBD attachment tool for this procedure? I was no aware this was required. Sounds like it may have to be something I take it to the dealer for? Again, thank you for the input!

 

[99WhiteC5Coupe]

Thanks for the response sir. I did not. You said using a computer, I assume you need a special program and OBD attachment tool for this procedure? I was no aware this was required. Sounds like it may have to be something I take it to the dealer for? Again, thank you for the input!

Yes - a Ford dealer would use their proprietary computer hook up to cycle the ABS shuttle valves while flushing the brake fluid.

I have read of other scanners that can be used to do this, but I do not have a recommendation.

You may want to tow it to a dealer (or shop that has the capability) to flush it.

Best of luck to you.

 

[RC32]

thank you!

 

[Yupster Dog]

Thanks for the response sir. I did not. You said using a computer, I assume you need a special program and OBD attachment tool for this procedure? I was no aware this was required. Sounds like it may have to be something I take it to the dealer for? Again, thank you for the input!

Yes (PC with windows)
FORScan is free (there is a FORScan section on the main page)
All you would need is the OBD wire. (for less than that dealer visit)
Then you would be set for scanning your truck in the future. A lot of useful tools on FORScan.

 

[RC32]

perfect, really appreciate all the input guys!