Help! 2006 Mariner Hybrid Braking Problems
 

I recently purchased a used (36K) Mariner Hybrid. Love the car, but about a week after buying it the service brake system lights came on. I took it to the dealer, which proceeded to bleed the system. They gave it back to me and it was fine for a couple of weeks. Then the lights came back on. They took it back in, bled the system again and replaced the master cylinder. Unfortunately, they just called to say that that didn't fix the problem. The dealership has admitted to me they don't know what the problem is and don't know what the next move should be.

Any advice on what to do now? Help!!!

may have to check the hard lines that run throughout the vehicle to check for leaks as well as the ends and hoses.

I imagine you don't have a leak, right? How does the pedal feel? Mushy or soft? Is it hard to depress or did it seem to change over the course of time after you got it back from the dealer the 1st time? If not, it's probably nothing major, maybe a dirty or faulty sensor triggering the light.

Hey Conan, when I got the car back the pedal felt a little touchier (maybe jerkier) than before but not mushy or soft, and not hard to depress either. Someone suggested to me that there was recall work that the vehicle may have needed, but I entered my VIN at mercuryvehicles.com and it came up that no recalls have been issued for the vehicle. So I'm not sure what they were referring to. Anything else that you can think of?

since it's the hybrid, it may be related to the regenerative braking system or another electrical issue in related systems. This is just a guess since I don't know much at all about the hybrid braking systems.

Update
 

Dealer decided that the hydraulic control was bad. I had not had a problem with the brakes - just with the light coming on. So they went ahead and replaced it. $3500. I went to pick it up and not more than .25 miles from the dealer the light came back on. I swung around to go back to the dealer in disbelief. Pulled up to a stoplight. Noticed while I was sitting there that now the ABS light was on as well. Shook my head. All of a sudden I realize that I am moving forward. Depressed the pedal as hard as I could and stopped the car. Got back to the dealer, depressed the pedal as hard as I could to stop the vehicle and turned it off. Went back in - they couldn't believe that I was back already. Explained that now I had little to no brakes. So it's back in the shop.

I think the hydraulic control was not the problem, but in their replacement of it they screwed something up and now I have a bigger problem than before. I am at my wits' end with the car and with the dealer.

bugger!

yeah... unless the booster is sucking fluid out of the system or they forgot to tighten up something and it was spraying brake fluid everywhere... I got no ideas.

Time to find a new dealer service dept to work on it

I agree, maybe the dummies forgot to bleed the brakes this time. I wonder what will they do when they get done replacing random parts to try to fix the problem. All you wanted was to find the cause, if there was one, and get the brake warning lights off. Now look at the madness they have caused. Hopefully they will get it right this time and you can enjoy your new Hybrid. Just remember (as Slymer wrote in an earlier post) that with regenerative braking the pedal will always feel a little different than any other car you have ever driven. I just read a good article in Motor Trend about it and they said it is something we will no doubt be getting used to in the future with Hybrid and electric vehicles that are inevitably coming. The science of regenerative brakes has come a long way in a short time and "will soon be perfected" the article went on to say. Keep us updated.