Hello Everyone:

I just installed the JCW R56 Brembos on my R53. Unfortunately the pedal feels like mush. The brakes have been bled several times and all the air bubbles should be out. I used ATE blue fluid in the lines. I know the problem is due to the huge calipers. Is there an easy fix for this mushy pedal feel? I read in a previous post where some had suggested going with the R56 brake master cylinder. Is this an option for the R53?

I really did not expect this with the new install.

Thank you!

 

Well, it wouldn't be caused by the calipers. A mushy brake can be caused by a number of things, but I seriously doubt caliper flex would be an issue with your Brembos. Air in the lines would be my first guess. My second would be either inappropriate pad choice or failure to properly bed in the pads and rotors.

 

I know in the literature for r56s, after installing it they do a ecu retune for the bias on the brakes.

Now I don't know how much they do but I doubt it has to do with mushy brakes.

I agree with Martinb, mushy brakes are mushy brakes for the most part and it's always the usual suspects.

 

I have the TCE plus 3 kit with the 4 pot FSL calipers and they are not mushy at all.

How did you bleed your brakes?

 

Thanks for your replies. Originally the installer was using a pressure bleed then the machine broke. They then used the two man technique where one person would pump the brakes. He bled them 5 times this way. I am also running braided stainless lines.

What is the proper bed in procedure for rotors and pads?

 

The techniques does vary by brake pad manufacturer. Most ask that you heat up the rotor and pad through repeated 60-10 mph stops, typically 6-10 to get the rotor red hot. You want to transfer some of the pad material onto the rotor. Then cool down the rotor by driving for a while (10-15 minutes) while not using the brakes (much). Then park and cool down but do not use the hand brake (but leave it in gear). Note, there can be some smoke!

I would bring it to a place where they can use the automated bleeding machine. I typically bleed to brakes manually 3-4 times a year but when the pedals just become too mushy generally from air bubbles, I bring it to Kyle, my mechanic) and he fixes it for me with the bleeding machine.

 

And make sure that if a pressure bleeder is used that is be the type that separates the fluid from the pressurized air. The cheap ones don't do that and when you pressurize it, you put air into the fluid. It must have a bladder or diaphram or something that keeps the pressurized air separate from the fluid.

 

One more question...did all 4 wheels get bled? If not air could have gotten into the rears. That would make the system mushy. Start the bleed from the right rear, then to the left rear, right front and last the left front.

 

^you always bleed caliper closest to brake master cylinder and then away.

I don't know the exact order on a mini but most shop manuals tell you the order.

 

Then go back and do it all again.

 

Either way, the point is air can get in where you don't expect it and it takes a fair bit of effort to get it all out. If you let the fluid drain out of the master cylinder you could have air stuck there or in the ABS parts.

 

I am very interested in the literature you mentioned about the ecu retuning the brake bias for a R56. I am not aware that Mini did that.

I know that that is a tool that recycles the ABS so you can bleed them.

 

^I can't find it online but the catalog that was in the car when I bought stated it something like that.

It could be all marketing too.

 

Yes there is a program that is updated when you get the JCW Brembos. It alters the ABS/DSC

 

Can you provide a link that explains that more. I am interested in reading more about this.

Altering ABS and DSC is not necessary changing the brake bias.

 

I don't recall what it does. I just know that anytime we install the kit we have to reprogram the ABS.DSC module afterward.

 

No problem. Just working through some thoughts about changing my brake bias a little since installing a BBK up front. Wanted to read more about it before doing anything.

 

Well I found some info in documents I cant share. But it simply updates the ABS/DSC to understand that there is a higher braking force and recalculates the ABS pulse in an ABS event and how the braking is controlled during a DSC event.

 

Thanks for finding that material and posting it.

It does confirm it is not a brake bias adjustment.

 

Thanks everyone for their responses. I have benefited immensely. It ended up being air in the front brakes. A good bleed fixed the problem.

:D

 

 

Wait a second, I thought you bled furthest away, passenger rear, then drivers rear, passengers front, then drivers front.......

As far as the mushy calipers, that sucks, sound like air to me.....

Bedding in the pads, I usually go on a straight road in a remote area and go 30-10 with firm pressure on the pedal for a quick stop without putting all your weight onto the pedal, then 50-10, 50-10 again and then 60-10, 60-10 again and thats it...... Then make sure you don't use your brakes on the way home and park it in the driveway for a bit to allow the pads/rotors to cool. I am sure there are other methods but never had a problem with my method....

 

+1!

Furthest away first, closest to master cylinder last.

How all the manuals I have looked at over the years state it. Just checked the R53 manual and found the same, stated unmistakably, wheel position by wheel position, starting from rear right on a left hand drive car.

 

Yeah, sorry I got mixed up.

also I thought it was brake bias but clearly it's just the abs / dsc difference.

sorry again! there I go dissing missinformation.

 

I have found that for bleeding or flushing brake fluid periodically use of a Motive pressure bleeder works very well and isn't very expensive ($55 + ship). See this link, this is the one which works great on my '07 MCS: http://store.motiveproducts.com/euro...-0100-p34.aspx If you have air in your system, I'll bet you can eliminate it with one of these. Good Luck