Strange Brake Issue - 2007 Mitsu Eclipse

[caseyctsv]

OK CR auto repair experts. I have a strange brake issue in the car I bought for my daughter. It is a 2007 Eclipse- the brakes feel great and strong normally. However, if you hit a patch of ice the ABS activates as it is supposed to but afterwards the pedal is very soft. You can "pump" the brakes back up at the next stop and all is good. They will feel great until ABS kicks in again. It seems like this is a known problem with this model but I have not found the "cure" yet.

[POS VETT]

Internal leak within the ABS valve body?

[STEVE-O]

Internal leak within the ABS valve body?

 

This is my thought there is a leak, fluid level low at all?

[caseyctsv]

Fluid levels are fine - also no visible leaks. Works perfectly as long as the ABS does not engage.

[STEVE-O]

Valves inside the module could be sticking until you pump and add more pressure orcing fluid back through

[caseyctsv]

The other wierd symptom - after ABS is engaged and the pedal is soft, it makes a "whistling"sound from under the dash everytime the pedal is pushed. It sounds crazy, no other way to describe it. Put it in park,pump the brakes, all good. Especially if you shut it off, pump the pedal, then restart.

[STEVE-O]

Hard to tell withiout being in person sound could resonate through the firewall etc. It's honestly best guesses without being there in person but it sounds like it's def some sort of problem within the abs main body

[caseyctsv]

Yeah that is what I think the research is showing - ABS Module / pump

[caseyctsv]

Not really wanting to pay 485.00 for the part

[cdk 4219]

I have a 2009 Eclipse GS. Recently, after I had to push the brake pedal really hard to avoid an accident (was cut off on a highway), I noticed that the pedal became pretty soft, and braking itself got far less efficient. Since no leaks were found, all the symptoms pointed toward the master cylinder. It was replaced by an expert mechanic, who also bled the system. That helped somewhat, so braking is better, but a few issues remain:

the brake pedal is still "spongy". Initially, it feels almost normal, the brakes start to engage, and then in goes down with little effect on the brakes, until I push it even further

When I release the pedal, I can hear a whistling sound, as if air is being sucked in

With the engine off, I can hardly push the pedal at all. I have read some posts on this forum as to what may be wrong, and the master cylinder was named the most obvious suspect with respect to the first problem. As I said, it was replaced with a brand new one, which, of course, can be defective too, though the likelyhood of this is low. But the whisle puzzles me. The booster apparently works...

 

I wonder if anyone has experienced a similar problem, and what was wrong?

 

Thank you in advance.

[cdk 4219]

Join Date: Jan 2008

Location: Des Plaines, IL

Vehicle: 08 Eclipse GS

Posts: 251

Rep Power: 8

Boomko will become famous soon enough

So i found tread about common problems and looks like it proves my issue. I started having soft pedal issue too at ~62000 it suck. I totally disappointed with mitsu quality. I took to dealer they messed around for 3 hours and apparently fixed the issue just by bleeding brakes. but the problem came back like in 3 days. according to them its abs unit valves got stock and no brake fluid going to the rear. if problem reoccurs they said i need to change abs unit. sucks!!! lots of $$$$$ and Mitsubishi doesn't stand behind the issue although i noticed its very common.

So is there any way to fix those valves without replacing all unit?

[POS VETT]

Wonder what the root cause is.

[caseyctsv]

Not sure but those are the threads I found too. It is not an unusual problem. I learned of the "temporary" fix the same way - Google search. If I put it in park,pump the brakes, shut it off,pump the brakes and Fire it back up the brake feel is perfect.

 

I was hoping someone here had conquered this piece. I do not believe it is te master cylinder as the brakes feel great most of the time and it holds pressure just fine.

[Crossle]

If there is a whistling sound under the dash when the brake is pushed, I would be checking out the brake booster seal where the brake pedal rod goes through the firewall.

 

Just a thought. Although odd and unlikely that a bad booster would only happen after the ABS scenario, cars make liars out of mechanics every day.