Help figuring out elusive R53 brake problem

Tom2112 · 02-09-2012, 09:48 AM

OK, I am at my wits end, and I'm about to get rid of my R53 because it is going to get me killed.

My 2005 R53 has 48,000 miles on it, and over the last couple months the brakes have become mushy and inconsistent. I've been getting a LOT more brake pedal travel for the same amount of braking, but not always the same amount. Also, under heavy braking (like when someone does something stupid in front of you in traffic), the car becomes unstable. It isn't pulling to one side or the other. The car feels like it will go into a spin-out. I always lay-off the brake before that happens, but it scares the crap out of ya. It's not even consistent which way it wants to spin.

So, what have I done about it?
I replaced my pads - fronts in November, backs in December. When I did the backs, I noticed that the back driver's side pads were unevenly worn. The inside pad was down to nothing and the outside pad had over a 1/4 inch of pad left. Also that caliper's piston was very difficult to compress to put the new pad in. I asked my dealership about it and they said "Oh, yeah. That happens. It's pretty common." WTF!?!

In December, I had the car in for service for an electrical problem. It ended up being the coil pack, which had burnt one of the connectors to the plug wires. So a new coil pack, plug wires and plugs later, it was running OK. While it was at the dealership I told them about my brake problems. They flushed my brakes to the tune of $200 and it made no difference. (As a side note, I had a lot of trouble with the dealer over this repair, and won't be returning to them - ever. Shame on you MINI of Pittsburgh.)

So I took it to a friend of mine that is a mechanic. He doesn't normally work on MINIs, but he took pity on me. I asked him to bleed the brakes, check them over for problems, and while he was at it, put steel lines and upgraded fluid in. When I got it back from him, the mushy brake problem was worse! I've only had it back one day, but I'm getting a lot more pedal travel than before. The braking seems more consistent now, but I need to put more miles on it to be sure. He's at a loss. I'm at a loss.

Anyone have suggestions before I trade this car in?

**minimark** · 02-09-2012, 10:02 AM

You may have a bad caliper sucking air and or a bad master cylinder.. Would seem to have been found when bleeding by the so called experts though.. 2cents

I see you are in PA, how far are you from Helix in Philly? If it's not to far, I'd call Eric at Helix and take it to them, they'll get it straightened out.

**goaljnky** · 02-09-2012, 10:30 AM

^x2

**ScottinBend** · 02-09-2012, 10:56 AM

Sounds like a master cylinder......and

to Helix

quikmni · 02-09-2012, 10:58 AM

I agree with maybe the master cylinder leaking. Since the brakes have been bled and it sounds like people have inspected the system for any leaks, I would also guess that you still have air in the brake system, such as in the ABS where it can be hard to get the air out of the ABS. It might take multiple bleedings to get the air out of the ABS block. It would be best to take the car to a shop that can properly cycle the ABS while bleeding the system.

**k-huevo** · 02-09-2012, 11:03 AM

The rear brake pistons must be fully screwed in when changing pads. If fluid weeps around the bleeder nipple instead of only through bleeder valve when opening, could be a cross thread or galled nipple. As for uneven wear, there could be a kink in the P-brake cable.

Minidave · 02-09-2012, 11:51 AM

If your rear caliper is sticking it could be overheating the fluid causing it to boil giving you a mushy pedal and causing inconsistant stopping. I'd take a good look at that rear caliper before I'd replace the master cylinder.

The clues are there if you're paying attention.....

**Crashton** · 02-09-2012, 12:32 PM

Could be a few things, but to me it sounds like the master cyl has an internal leak. I think I'd look into that.

**Jason Montague** · 02-09-2012, 12:50 PM

With all of the above advice................Go to Eric @ Helix in Philly

Jason

geowit · 02-09-2012, 12:57 PM

If he's going to MINI of Pittsburgh, that's the other end of the state from Helix. I would also try to contact PittStop MINI to see if anyone local can recommend a good alternative to the dealer.