I need to change the front brake pads on my 2011 Mini Cooper. I have a Haynes Manual, which tells me to clamp off the flexible brake fluid hose to the caliper. But the hose isn't that flexible and doesn't look to me like it would pinch closed without damaging it. They don't say why you should clamp off the hose, but I'm guessing it's to prevent any possibility that brake fluid will be forced back through ABS system. But they also say to open the bleed valve before compressing the piston, which I would think would avert this problem. Any opinions on this?

 

What they recommend is likely best practice.

That said, I've never done that with a pad change, on any vehicle (mostly since I used to loathe brake bleeding...less a concern now with a pressure bleeder I just bought).

Compressing the piston back into the caliper, you will displace a few cc's of brake fluid. In the dozen or so pad changes I've done across a bunch of cars, this never caused a problem (including the rear pads on my 2012 MCS).

HTH, and just my opinion (formed after doing this a few times).

 

Wow, this is a REALLY bad and totally unnecessary advise.
To change the pads, you remove 2 caliper guide bolts, swing the caliper off the pads (remove brake wear sensor on 2 of 4 wheels), replace the pads, push the caliper piston back in (new pads are thicker), and bolt the caliper back on to spec torque (either 20 or 26 ft.lbs).

Plastic Brake wear sensor gets brittle with heat cycles, so it may break as you try to remove/re-install it. Then you either replace it, or tied it to the strut tower and forget about it.

Done.
About 1 hour for all 4 corner.
It takes longer to jack the car up and remove the wheels than it does to swap the pads.

No need to do anything with the hose.
No need to do anything with the bleeder valve unless you are also flushing the brake fluid.


No need for that. You are more likely to introduce air into the brake caliper, then have dirty fluid travel very far.

If you think your fluid is dirty or old, flush it !
Do it at least once every 2-3 years, or before each driving school/DE.

Please throw away Hayes manual, and get Bentley: http://www.amazon.com/MINI-Cooper-R5...bentley+manual

a

 

The fluid isn't dirty. Car has just under 40 k miles, so this would be the first pad change. But I don't want to force any fluid back through the ABS system.

 

You can't force brake fluid more than 3-5" up the line by compressing the brake caliper. The fluid volume is just not sufficient to travel any further.

And 40K and 3 year old car is absolutely due for a brake fluid flush. But that does not need to happen at the same time as the brake pad change. The only connection between the two procedures is take the wheels off the car.

a

 

Just talked to a mechanic I know who's done work for me on other vehicles, and he says he recommends brake flush every 24K miles. So I'm definitely going to have that done.

 

I appreciate everyone's input. So here's what I decided: After talking to the mechanic (see above) I've decided to bite the bullet and take Minnie in to him to do the work, for the following reasons: 1) he says he turns the rotors (assuming they have enough metal) every time he changes brake pads because new pads need a smooth surface to seat properly (makes sense, right? 2) he also says everything in the brake system should be checked, not just the pads (makes sense, too). And 3), as above, I'm overdue for a brake fluid flush. His reason for having a flush every 24K is not so much dirt, but because brake fluid absorbs water over time, which can cause 2 problems: it can cause brake fluid to boil under certain circumstances, and it will corrode the system.

 

That seems a little soon to be doing a brake fluid flush. Brake fluid, if not contaminated is made to last the "life of the car". I would avoid flushing brake fluid unless you see it getting dark, or experience more pedal travel before brakes engage (air bubbles in system).

I have gone 100K miles on other cars before bleeding. Had no problems either.

Pads are probably good for about 40-50k miles, depending how you drive.

 

That is absolutely NOT true.

Brake fluid is hygroscopic, absorbing water vapors overtime. That, by itself, is not fatal, but it introduces 2 distinct problems:
1). Water is corrosive. The more of it gets into the brake fluid lines, the more metal components start rusting (brake calipers, ABS pump valves, etc). This doesn't happen overnight, but absolutely will cause expensive problems if you intend to keep the car (vs. lease->abuse->dump)
2). Water's boiling point (212F) is significantly lower than that of most brake fluids (400+F for DOT3 street fluid , 600+F for track brake fluids). When you brake, pads and calipers heat the fluid. When you exceed the boiling point, the fluid turns into vapors, and your brake pedals goes to the floor w/out slowing the car. Extremely not fun. To be avoided at all costs !

That is why MINI covers brake fluid flushed every 2 years under its pre-paid maintenance program.

You can't really visually inspect the brake fluid in the lines, except while bleeding it and watching the color/quality of the fluid exiting the lines.

The fluid in the reservoir is just an "extra" amount of brake fluid to compensate for the brake pad wear (calipers extend further, need more fluid), and it doesn't circulate through the system. You can't tell much by looking at it. That fluid is in contact with the air, by definition, and all the air in the fluid will transfer to the air layer in the reservoir.

Which is why flushing brake fluid pro-actively (a quart of quality brake fluid is ~$15 !!) is such an no-brainer.

If there are bubbles in the lines, your brake lines are beyond neglected, and you will be practicing impact braking the next time you need to stop in a true emergency!

a

 

Pads are probably good for about 40-50k miles, depending how you drive.

The 'line clamp' issue is debated widely on many car forums and I personally DON'T for pad changes. When I had to replace a cylinder on the rears of my 79 and didn't want to drip fluid all over I DID discover that this is not only NOT a whacked idea ... but there are special tools made to clamp a brake line (or other automotive rubber line) without damage.


Harbor Freight $8; I use heavily padded vise grip, "just tight enuf" ... secret is to spread the pressure ... don't pinch or cut . .

MINI OE pads are quite soft and wear FAST ... I'm a pretty easy driver and still go thru MINI pads at around 25,000 ... I do MINI brake work for others and have seldom seen them go a lot farther. When I change pads I just loosen the res' cap and push the pistons back - WATCH THE LEVEL - & don't forget to turn the rears. Have done dozens of sets since 2006 (when I first ditched OE pads on my 02 b4 heading to MOTD) with no problems.

MINI does not recommend resurfacing their rotors. Basically the rotors are thin to begin with so if you resurface them you run a real risk of dropping below minimum spec' FAST. "In the beginning" MINI policy was to replace rotors with every pad replacement . . . IME, with a change of pads around 25k is has been safe to go 2 pad sets to a rotor. So long as there is no unreasonable grooving the new pads "bed" to the existing surface just fine. (track guys who change pads 'tween runs don't turn the rotors do they?)

In regular road use, getting the fluid/absorbed water to a 'boiling' temp is unlikely .. not impossible (mountains) but unlikely. If you auto-cross etc, different story.

I drove a 95 Miata for 12 years and when I sold the car it was on the original brake pads and fluid with 120,000 miles. Pads had a lot of meat left . . . at 8 years we crossed the Rocky's on a cross country drive.

***************

MKI, MKII terminology is Mini

for MINI, folks generally use GEN1 and GEN2 (for now)

it avoids confusion

My 79 (very modified) is a MKIV

My 2002 GEN1

2007 GEN2

and 2014 ST-3 a blast

 

[QUOTE=afadeev;3953867]That is absolutely NOT true.

Brake fluid is hygroscopic, absorbing water vapors overtime. That, by itself, is not fatal, but it introduces 2 distinct problems:
1). Water is corrosive. The more of it gets into the brake fluid lines, the more metal components start rusting (brake calipers, ABS pump valves, etc). This doesn't happen overnight, but absolutely will cause expensive problems if you intend to keep the car (vs. lease->abuse->dump)
2). Water's boiling point (212F) is significantly lower than that of most brake fluids (400+F for DOT3 street fluid , 600+F for track brake fluids). When you brake, pads and calipers heat the fluid. When you exceed the boiling point, the fluid turns into vapors, and your brake pedals goes to the floor w/out slowing the car. Extremely not fun. To be avoided at all costs !

That is why MINI covers brake fluid flushed every 2 years under its pre-paid maintenance program.

Just what my mechanic said . . .

As for the line clamp, the much maligned Haynes Manual shows a clamp that is in the shape of an elongated "U" with what looks like a rubber grommet inside the closed bottom of the "U" and a snap closure device at the open end. Kind of looks like a giant safety pin.