2015+ Brake booster replacement- SSM 45857

[Ecoboosted]

I finally got around to replacing my booster regarding SSM 45857- touchy or over sensitive brakes. I was in a hurry so I didn't take any pictures, but I couldn't find anything on the internet to help so I figured I would document what I remember:

 

1. Disconnect battery (+) terminal, 10mm
2. Remove airbox cover and air filter, 7mm clamp on the intake hose, electrical connector at the front.
3. Remove air box, 7mm bolts at radiator support, the box is held in on the bottom by rubber grommets so it "pops" out
4. Loosen battery hold down (8mm) slide battery forward and disconnect (-) cable, 10mm
5. Remove battery
6. Remove battery tray, 8mm bolt towards the firewall in the center, and another towards the front on the driver's fender side of the box. The other 8mm bolts that look the same are there for the battery hold down and do not need to be removed. This is where a picture would really help, but if you leave the hold down bracket attached you can remove all of the bolts and not lose the bracket.
7. Remove the battery tray support, 13mm- one nut and one bolt
8. Pull out the vacuum line from the booster, remove all electrical connections (one at the master cylinder and one on the bottom of the booster.)
9. Inside at the brake pedal remove the pin that holds the booster arm to the brake arm, use needle nose pliers to pinch the plastic retainer and at the same time pry the pin out. I used a metal trim removal tool (forked end) to pry with.
10. The upper left nut holding the booster on is the most challenging to get to so I removed it first. I used 2 swivel joints and a deep 13mm with a 6" extension to turn it out. The other booster nuts are right in front of you. You can fully remove the nuts at this time
11. Back in the engine bay: break the 2 brake lines loose at the ABS block to the right of the master cylinder- these require a 15mm crows foot. 8 bucks for a whole set at Harbor Freight. Be ready to lose some fluid, I had rags all around it to keep it clean, then immediately put a ziplock bag over both lines and zipped it tight.
12. Remove the booster and master cylinder as 1 unit. Try to keep the open brake lines at the highest point to minimize fluid loss.
13. With the booster/ master cylinder out, remove the master cylinder (it still has the 2 lines attached to it that hooked up to the ABS block), 13mm
14. Remove the sensor at the bottom (it won't come out with the lines still there, so you have to remove and install it with the master cylinder removed from the booster.) It's tight, it just prys out.
15. Install the sensor onto the new booster.
16. Replace the o-ring on the master cylinder.
17. Attach the master cylinder to the new booster.
18. Replace the gasket for the firewall.
19. Slide the new unit into the engine bay, line up all the bolts and slide it into the firewall- don't push it all the way in yet. There might be enough range of motion in the pedal that you can line it up with the booster all the way in, I just did it this way to make sure I didn't have to pull it back out or misalign the booster arm.
20. At the brake pedal, make sure that the booster arm lines up with the brake arm. I rested a ratchet on the brake pedal to hold it down with the booster arm in the correct place, then slid the booster all the way into the firewall.
21. Insert the pin to the brake arm
22. I started the nuts inside, but did not tighten them at all so that the booster could still move around
23. In the engine bay, get both the brake lines started into the ABS block. Be careful not to cross thread them. There are flexible sections in the lines, but it was still good to be able to move the booster around to get the lines to start easily.
24. Tighten the brake lines
25. Tighten the booster bolts inside
26. Have someone pump the brakes and bleed the lines at the ABS block- only bleed the lines that were removed. 
27. Replace the vacuum line at the booster, it's tight.
28. Replace electrical connectors.
29. Replace battery tray support, battery tray, air box and hook up battery.
30. Run ABS brake bleed service routine
31. Bleed all lines. 
32. Enjoy!

 

The booster comes with the o-ring and new nuts for the master cylinder, and the firewall gasket.

 

I may have forgotten a small thing or two (like where some wiring is attached to the battery tray and air box that have to be pryed out) but I think this covers all the main stuff.

MC-10081005-7690.pdf

Edited November 2, 2020 by Ecoboosted
typos