2001 3.5l limited Montero. ABS and brake lights turn on as I'm pulling out of a parking space. Hit the brakes a few times and a buzzer starts going off. I drive it around in the parking lot testing the brakes and they lose all power. I had it towed home, it's late, and the only thing I've checked is the fluid level which is fine. There was no noise from a leaky booster, or any other warning sign before this.

I have a FSM for an 03 and so far it looks like I need a diagnostic tool in order to figure out what failed. There's a recall on the booster that I just found out about. What could it be besides booster or master cylinder?

 

hah. New cars.


Why think its something else when theres a good chance, likely, its the booster.

 

Ha is right! First new car I've ever had with brake failure. Felt like I was on the starship enterprise during a red alert.

It's definitely the booster, I get no peddle action after pumping and starting. My problem is how to diagnose and repair/rebuild it? The only place I can find an entire booster replacement is amazon and they want over $2100 for a new one and $1000 for refurbished. This is my first rodeo with hydro-boosted brakes as well.

There was a recall on the accumulator for this truck but I don't know if it has already been replaced. Mitsubishi is closed on Sunday, even the call center. All I know is my accumulator has a pink dot on top of it.

 

Hopefully this will help someone:
Took advantage of AAA and had it towed to a shop to get the codes. Came up with 63, 53, and 51. 53 is a pump motor failure. Of course the tech that read the codes didn't want to touch it any further, it was either replace the whole unit for $2k+ or nothing. Had it towed home and took the day off. These photos show what's wrong with the motor:

good side of shaft https://i.imgur.com/4ijO3Jy.jpg

Bad side of shaft https://i.imgur.com/dUi0X0K.jpg

I only have ~170k miles and have never abused this truck. Mitsubishi wants $800 for a replacement motor. I like the truck, but I will never recommend Mitsubishi again.

It's an easy job though. You can easily have the booster out and replaced in a little over an hour. I'm not sure how long it will take to bleed this thing though. Motor replacement is pretty obvious as well.

 

sorry to hear it bro.

try a car from <1995 next time. they tend to keep going if you look after them.

 

I hear ya.
The unbelievable thing about this is that it really should be a scheduled maintenance issue. I blew the motor out before taking those photos. It was filled with dust from the brushes and worn copper. Anything that can lead to catastrophic failure and death needs to have a maintenance interval. It should have been replaced at 100k IMO.