Posted this in "Beneath the Bonnet" but it might get more traction here.

Bled my brakes yet again, this time with Blue to make sure the old fluid (Motul) was completely flushed. The brakes still feel mushy. Like there is 2+" of travel before they bite. Could there be air trapped in the ABS system? DSC? I didn't have the car in the "on" position when bleeding, should I have? I've never read this being required for the MINI's system. I know some ABS systems have bleed valves does the MINI?

I'll be getting a test drive or two in other MINIs so that I can compare the brake peddle feel to my own.

Any help appricated. Failing this I'll be getting the MINI dealership to bleed them until they are right.

Cheers,

Paul

 

i had a similar problem. i had just tracked my car and the brakes were shot. i bleed them and that helped some. the dealer replaced the master cylinder and that didn't really help. my brakes still feel as though they just aren't all the way there. replacing the pads helped alot. i'm thinking about SS brake lines but wonder still if there is another problem. the MINI has small rotors for track use but i can't afford a big brake kit.

 

>>i had a similar problem. i had just tracked my car and the brakes were shot. i bleed them and that helped some. the dealer replaced the master cylinder and that didn't really help. my brakes still feel as though they just aren't all the way there. replacing the pads helped alot. i'm thinking about SS brake lines but wonder still if there is another problem. the MINI has small rotors for track use but i can't afford a big brake kit.

I'm sponsored by a brake pad company,
Williams Performance Friction so I constantly have new pads on the car and run a seperate set of track and street pads. This problem has existed for a while but it's just now getting me pissed off. I don't think smaller rotors has anything to do with it. I think there is air in the system and right now I'm suspecting the clutch. As the brakes and clutch share the same fluid. So I'm going to bleed off the clutch tomorrow and see what happens.

I'll keep you posted.

Paul

 

No bleed value on the ABS... no need to have ignition in the "on" position (at least i've never had it "on" when I've bleed my brakes).

I was going to really stretch and suggest pad taper... but if you're on new pads, that cant be it.

Like you said, there must air trapped somewhere... clutch bleed is probably a good next step.

 

Glad you guys are discussing this. I got a little air into the rears while changing pads, so I bled them yesterday. Interesting thing: after bleeding the rears (right first, left second), the brakes were TIGHT. Pedal feel was awesome. But then when I moved to the front and started bleeding, the mushiness (or "extra 2" of travel as paulmon put it) was definitely there. Also, I recall reading in another post recently that someone heard a slight "whooshing" or sucking sound when s/he was bleeding the FRONT brakes, and the sound was not repeated in the rear. I can't think of why it would be different in the front, since the only thing that really changes is proximity to the master cylinder. Although I guess proximity to clutch and clutch reservoir is there as well. I'm wondering if I should have gone back and re-bled the rears, since that tightened everything up so much initially; although that does sort of run counter to normal bleeding procedures (furthest to closest). Incidentally, this is all confirmed by both myself and the most independent of analysts: my wife--aka the pedal pumper! :smile:

Let's keep this going and see if we can't figure it out!

 

No other thoughts yet, eh? Well, I've got a few:

1) The braking system is not "fully active" unless the car is actually running. Just try sitting in the car and pumping the pedal with the car off or even with the car on, but not running. You can pump up the pressure until the pedal is too tight to move, but then start the car and the pressure releases.

2) There is just too much travel before the brakes engage. I don't think that there's any air in the system, as I've done a full flush twice with similar results. Maybe a little tighter, but not by much.

3) There's a whooshing sound that is sometimes more noticeable than other times, but it can happen while opening any bleeder on the car. I originally noticed it while doing the fronts, but then tried re-bleeding the rears and heard the same thing. Weird stuff.

4) Is there any chance that the clutch running off of the same system has something to do with this?

5) Does anyone know of a method of simply tightening the brake pedal? I think that there is just too much travel built into the system. Once it engages (about 2-3" in), the brakes are there and it's lights out. But I don't like having that two inches to play with, especially at the track when 2" becomes 4" after 5 laps.

Anyone have any thoughts on this?

 

>>Glad you guys are discussing this. I got a little air into the rears while changing pads, so I bled them yesterday. Interesting thing: after bleeding the rears (right first, left second), the brakes were TIGHT. Pedal feel was awesome. But then when I moved to the front and started bleeding, the mushiness (or "extra 2" of travel as paulmon put it) was definitely there. Also, I recall reading in another post recently that someone heard a slight "whooshing" or sucking sound when s/he was bleeding the FRONT brakes, and the sound was not repeated in the rear. I can't think of why it would be different in the front, since the only thing that really changes is proximity to the master cylinder. Although I guess proximity to clutch and clutch reservoir is there as well. I'm wondering if I should have gone back and re-bled the rears, since that tightened everything up so much initially; although that does sort of run counter to normal bleeding procedures (furthest to closest). Incidentally, this is all confirmed by both myself and the most independent of analysts: my wife--aka the pedal pumper! :smile:
>>
>>Let's keep this going and see if we can't figure it out!

Chitown,
How did you get air in the brake line while only changing the rear pads? From what I have read from Randy Webb's site, he does not mention "bleeding" the brakes, at least therte was no place that I saw. I will admit that I am not a big time gear head or even pretend to be, but I don't see how you were able to do this. :smile:

 

Good thoughts Chitown.

On my Volkswagon, the brake/clutch sharing was an issue. An occasional bleeding of the clutch line helped.

I like the standard 2 inches of play. It brings the brake pedal in line with the gas pedal. My size 13 feet make heel toe shifting really really akward, so I use the inside/outside foot method. At the track, I havene,t noticed an extra 2 inches of travel since switching to ATE blue. Maybe stainless steel lines will help.

Has anyone bled the clutch line? How do you do it?

 

While changing pads, I was having a hard time getting the piston to retract (as I ALWAYS do, but I appear to be the ONLY person who has this problem...odd), so I cracked the bleeder to relieve a little pressure. That let a little air in, so I had to bleed it out.

Good thought, it probably does help with the heel toe thing, though I hadn't ever thought about it. I would just love to get that feeling of "instant" brake affect without having to fiddle with the two inches of play. I wish that it was something that I could just tighten up. Hell...why not just START the brake pedal two inches closer to the floor instead of giving me that two inch cushion.

As far as bleeding the clutch goes, there's a bleeder valve identical to the ones on the brakes that's located inboard of the left front wheel. Supposedly, one needs to remove aftermarket skidplates to get to it. I haven't tried to get there just yet. I'm actually quite convinced that there's some air in my clutch line now, though I don't know how it would have gotten there. I get a pfffft sound off of my clutch a lot, similar to the sound I often get from the first two inches of brake travel. I can't help but wonder if I'm alone in this, of if I'm just too sound sensitive.

Does NO ONE have any ideas on how to eliminate the useless first two inches of brake pedal travel for more of an "instant" brake feel?

 

>>

Chitown_COOP,
This morning I replaced my front rotors with a set of EBC slotted & dimpled ones and EBC Green Stuff all the way around. I had no problem pushing the pistons back.

For the rear pistons I used a set of needle nose pliers. You put the two noses into a set of the dimples on the rotor and then push and turn. Both of the rears went in very easily, in fact, I have found this method even easier than the use of a 6" C clamp.

For the front pistons, I used just a big ole screw driver and applied leverage against the piston. While holding the pad carrier, I inserted the screw driver through the large hole of the pad carrier and then used the screw driver as a lever and pushed the piston back. Make sure that you have a one of the brake pads against the piston, either the new one or the one that you are going to remove. This method worked for me with no problems.

I followed the bedding instructions at this Bedding in new pads and rotors. When I finished with the 60->10 mph stops, the brakes were really smoking. By about the 5th stop, the brake pedal got very mushy and started to fade. After they cooled down, everything was pretty much back to normal.

paddy

 

Paddy,

I agree the fronts are a breeze. I've never had any sort of problem. For the rears I've tried the needle-nose method. That's been the only one that has ever worked for me, but it alwasy takes an amazing amount of muscle and patience to get them to retract. The last time I did it, I pushed and turned for the longest time on both of them, and nothing happened. I then cracked the bleeder screws and that didn't seem to help, but then on about my 10th try (and maybe 100th rotation) they went in like butter. This happened in a similar way on BOTH SIDES. It was really bizarre, and I have no idea what finally "flipped the switch" as it were, to make them decide to retract. I've also had a problem with the rubber boot "sticking" in such a way that it gets all crumpled up when rotating the piston.

I've got to change my brakes tomorrow morning (got an appointment with the dealer on Monday...looking for some warranty rotors), and I'm going to try the C-Clamp method. I still don't understand how that's going to work since the "face" or contact point of the C-Clamp is loose. What's going to make the piston rotate?

Why does noboday else have any problems at all with this!?!?!?!

 

Chitown_COOP,
The only other thing that I can think is to release the e-brake. I very seldom park with mine on. If you are working on the rear's the e-brake should not enter into the equation. That is the only other thing that I can think of. Good luck

 

Had the same problem when I changed out my brake fluid after a track session.

I bled the brakes with a pressure bleeder - improved but not perfect. The fluid would come out of the bleeder valve very slowly. I had the pressure bleeder pumped up to around 18 psi.
Repeated the process 2-3 times, still same results: still a little musy.

So, I tried the old school method: Jacked up the car on 4 jackstands, wheels off and this time had someone pump the brakes while I opened and closed the bleeder valve. Well, the fluid gushed out and pop there goes an air bubble.

Now I have a real firm brake pedal.

 

Hmm. Maybe I just have an air bubble trapped deep inside somewhere that doesn't want to come out. I've got COOP in for the 10K maintenance (among other things), and the Cooper loaner I've got has a GREAT pedal feel: really tight. I've noticed this before on a loaner.

I guess I should just do a full flush.

Thanks for the thoughts.

(And no, I don't have the E-Brake on when changing my brakes. I just must have really pushy pistons!)