Bleeding Procedure: Brembo BBK

[MNm3]

Hey guys,

Just wondering what the procedure is for bleeding Brembos. I know you start furthest from the fluid reservoir and work your way up, but the brembos have two valves per caliper. Which one do you bleed first?

Thanks!

[elh0102]

Makes no difference. Just remember, the first one is bleeding the line from the m/c to the caliper, so there is much less to bleed from the second one.

[rzm3]

From StopTech manual:

Note: The calipers and lines will need to fill with fluid, quickly draining the master cylinder reservoir. Keep a close watch on the fluid level when initially bleeding the system. Do not allow the master cylinder reservoir to run dry, and to draw in air. Doing so may result in the brake system needing to be serviced by a certified brake technician.

Bleed the brake system, using an 11mm box wrench, to loosen the bleed screws. The sequence for bleeding the brakes should be:

1. Right outboard bleed screw
2. Right inboard bleed screw
3. Left outboard bleed screw
4. Left inboard bleed screw

Though a torque wrench is not typically used on bleed screws, as a reference, the torque for bleed screws should be approximately 100-140 lb-INCH.

After initially bleeding the system, gently tap the caliper body with a mallet to dislodge any small air bubbles, then re-bleed the brakes.

After bleeding, apply constant pressure to the brake pedal, and check all connections - including the bleed screws, and both ends of the brake line - for leaks.

Warning: Brake fluid will damage most painted surfaces. Immediately clean spilled brake fluid from any painted surface, including the caliper. Though caliper paint is designed to resist harsh chemicals, prolonged exposure will damage the finish.

[JAJ]

Originally Posted by MNm3

Hey guys,

Just wondering what the procedure is for bleeding Brembos. I know you start furthest from the fluid reservoir and work your way up, but the brembos have two valves per caliper. Which one do you bleed first?

Thanks!

The answer starts with a question: Have the calipers been disconnected, say to service the brake hoses or to overhaul or replace a caliper? If any of the parts are new, and you want to avoid having to re-bleed your new brake kit or newly installed SS lines after a few days of use, then you have to be a little more thorough the first time.

If "yes", then follow the order in the Stoptech instructions but bleed each caliper's outside bleeder (until you get clear fluid with no bubbles), then the inside, then the outside a second time, then the inside a second time. Between each cycle, tap the caliper body with a soft mallet - preferably hard plastic. Once you've done all four calipers, the go around the car again in the same order, and do two or three strokes on each bleed screw to catch any lingering bubbles.

Usually you won't get any bubbles on the second trip around the car, but it's quick and easy when the wheels are already off.

On the other hand, if it's just a regular bleed after a hot day of use, then just follow the Stoptech instructions. The mallet is optional.

The M3 has a stepped master cylinder, so the front brakes push though more fluid than the rears per stroke of the pedal. Check your fluid every ten or so strokes at the back, but move it up to every six or so at the front. The fronts push through A LOT of fluid every stroke, and running dry in the reservoir can't be fixed without a trip to the dealer to bleed air out of the DSC and ABS system.

[MNm3]

This is just some additional work being done after the install... the pedal still feels a little spongy. My stock brake pedal feel was better than this and I had SS lines with new pads. I would imagine that it should not be this way.

I also have had the car in to bleed air out of the ABS system already.

Are the ABS and DSC systems the same when it comes to bleeding air out of the systems? I mean if you bleed one (ABS) are you also bleeding the other (DSC)? Or is it a different procedure for both?

[JAJ]

Originally Posted by MNm3

This is just some additional work being done after the install... the pedal still feels a little spongy. My stock brake pedal feel was better than this and I had SS lines with new pads. I would imagine that it should not be this way.

I agree with you. What fluid and pads are you using? Some types of fluid produce a softer pedal, but it should still be as good or better than stock.

Originally Posted by MNm3

I also have had the car in to bleed air out of the ABS system already.

Then that should have cleared out any air in the calipers too, or so I'd expect.

Originally Posted by MNm3

Are the ABS and DSC systems the same when it comes to bleeding air out of the systems?

Yes. It requires a BMW OPS or OPPS tool running the CIP software to turn the various ABS/DSC pumps and valves on and off in the correct sequence to clear the air out, and it does both systems at the same time. Dealers have this stuff, but non-dealers usually don't.

Originally Posted by MNm3

I mean if you bleed one (ABS) are you also bleeding the other (DSC)?

Yes.

Originally Posted by MNm3

Or is it a different procedure for both?

No.

[MNm3]

Originally Posted by JAJ

Dealers have this stuff, but non-dealers usually don't.

.

Hmm. I did not take it to a dealer to have this done. I took it to a non-dealer. They said that is what they did. I'll have to ask them if they have the tool.

Thanks

[MNm3]

I am just using the pads that come with the Brembo BBK kit for street use and then DOT 4 fluid. I couldn't tell you which brand though.

I have hawk pads for track use and have not had a chance to try them out... 3 weeks and counting...

[JAJ]

Originally Posted by MNm3

Hmm. I did not take it to a dealer to have this done. I took it to a non-dealer. They said that is what they did. I'll have to ask them if they have the tool.

Thanks

Well, from what you're saying, you still have air in your brake system, regardless of how it got there.

This might be part of the problem. Or they may have done the job properly. There's no way to know.

Did you actually get air in the ABS/DSC system in the first place or was the ABS/DSC cleanout done as part of a flush?

[chris328i]

Stainless steel lines do not produce a better pedal feel unless the OE hoses are soft and expanding. If the new pads are not fully worn into the rotor then the pedal can be spongy even without air in the system.