So here's the story. I noticed my brakes hanging, like your foot was on the brakes all the time. Off to the dealership...they said it was the passsenger front caliper sticking. They order the parts I bring it back. On the way up I notice the problem is worse, in fact all 4 corners of the car were smoking when I got to the dealership. Also the brake pedal is extremely stiff and it is hard ot brake at all.

Dealership replaces caliper, caliper hose and all brake pads. I question why one corner would cause all 4 brakes to lock but they say that is the problem. The car seems fine when I get it back. No hanging brakes and brake pedal returns to normal.

One day later and I notice the problem is back. On the way to the dealership again it is now smoking my new pads and the brake pedal again is VERY stiff (you can hardly press it at all). They have the car now.

ANY idea what this is?? Could it be a master cylinder problem, some sort of brake booster or ABS issue? Could it be the driver front caliper also going bad and causing the same problem as before? The stiff pedal makes me think master cylinder but I don't know enough about how the braking system works.

Help!?

 

UPDATE: The mechanics have no idea. They played with the brake pedal itself but I already tried pulling up on the pedal while it was happening and it did not help. Brakes (all 4) still locking.

All 4 are locking so the emergency brake malfunctioning seems unlikely. The pedal returns to top so it is not a pedal issue. This leaves master cylinder, brake booster/check valve/vacume or ABS systems....

Any ideas out there.....they are keeping the car overnight!

 

Could this be ABS related?

Seems like it is were the Master Cylinder the brakes would under boost not over boost. It seems to be the same fo rthe Brake Booster itself. I would think the failure of that would underboost not over boost. If it is the ABS or an ABS wheel sensor it may apply the brakes??

 

Wow....44 views and not one idea. I must have found a good one.

 

hydraulic brake booster not releasing at all times,possible causes bad brake booster.

 

Thanks....here's today's update. The dealership has had the car now for 3 days. Today I finally got Mitsu to call them. As of 9AM Mitsu was saying Master Cylinder...as ot 11AM they changed that to brake booster. The new part will be here Monday of course since it is 2 weeks out of warranty Mitsu WON'T be paying for it. Of course there's no guarantee it will work and of course if it does not work I'll still be stuck paying for it AND the next part they decide to guess at. Am I having fun.....?

 

the booster seems to be an unlikely problem, unless it is binding somehow on the master cylinder rod. your description is of the brake system not releasing pressure, the boosters only job is to multiply the effort you put out. the abs system could be a problem as well, but it is less likely without any other symptom like a abs light or something. good luck

 

I agree. The dealership claims Mitsu said that in all cases reported with the same issue the master cylinder did not fix the problem and ultimately the brake booster did. I suspect in my case they will end up feeding both parts to the car at my cost. At least this way if I go along with their diagnosis and it does not fix the car I have some recourse....believe me if I pay for the booster and it does not fix the problem I'll want my money or my old part back.

The dealership has been pathetic. They don't seem to be actually testing or checking any of these parts.....just guessing and replacing. I'd like to say they have performed the diagnostic tests on the booster or master cylinder and that they've checked the ABS system for any error codes but my guess is that they have not.

To compound the problem Mitsu has also been pretty pathetic. They are just so sensitive to warranty issues on this car that they've made it a warranty nightmare. You'd think that they'd look at my car and say this guy has 34K on his car and still has the original pads on it....this is probably not a case of brake abuse....and when braking system parts like a booster or master cylinder are failing BEFORE the original brake pads wear out then the part is defective and should be warranted. Instead they say no....

Sad for a company struggling to survive and even more sad for an owner that has purchased 4 Mistu's from this dealership and WAS intently watching the Evo X.

This is looking like the end of my Mitsu road.

 

Update. They put the booster on THEN noticed they could not bleed the brakes. FINALLY after 6 days someone actually tested the master cylinder and it had a blocked port. They put the original brake booster back and replaced the master cylinder. So far it seems fine....only time will tell. What a mess...

Very hard to trust the car, the dealership or Mitsu after this one...

 

damm i was close, i could it fix you car if i was working on it oh well.

 

damn, sorry about your **** luck man, hopefully this is the final fix and they give you a bit of a break on the labor.

 

Nope no break on the labor $$. Between Mitsu and the dealer they could not have possibly done less.

I'm pretty sure this is the final fix...at least while I own it.

 

Ashame to see you leave. Everytime i get a new car and plan on modding it i always think of whats at stake. Good luck finding a car with the warranty your looking for ...
VW isnt gonna give it to you trust me on that ( IMO please respect )