Brakes Bleed - Still Mushy
I had my brakes bled for a routine schedule, but it still feels just as mushy as before. 27K miles on the car. Nothing serious, but it makes me wonder if the shop even did anything. I was expecting a stiff feel. It's all stock components. I bought the car used, so I'm not sure if this is the normal feeling as when it was new.
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They may not have been bled properly, there is a very definate procedure that has to be followed if you want to get a firm pedal with BMW stock brakes.a_ok2me said:
See: http://www.zeckhausen.com/bleeding_brakes.htm for all you need to know. I would take the car back to whoever did the work for you with a printout of Dave Z's procedure and ask them to do it again. I have always been happy with the performance of stock BMW M brakes, they don't have the rock hard pedal of most good multi piston calipers but they slow the car down well with a good pad installed.
Regards
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It's the relationship between the M5 master cylinder and the size of the caliper pistons. A proper bleed, stainless lines, and a high Cf pad like Axxis Ultimate can help. But it's not going to feel like a Porsche, or even an M3.gsfent said:
I'm working on a solution that might yield a very good pedal feel. That's all I can say for now. I hope to have an update within the next 3 or 4 weeks. I'll post photos and results when I've tested the solution on my car.
Are you changing the rubber guide pin bushings with brass and SS guide pins? Does the M5 have this type of set up? I run this on my E30 M3 and the pedal is more firm and the pad wear is perfect with both Hawk HP+ and HT10's for the track. Very cost efective as well.
Jordan
4 days and counting until I aquire her........
Jordan
4 days and counting until I aquire her........
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For this particular platform, the Brembo BBK has a softer pedal feel than the StopTech. But it's not something that you can generalize to all platforms. For example, the M3 pedal feel is nearly the same between the two. The StopTech is still firmer, but not by as wide a margin.MIB said:
This new solution won't be as simple as replacing the rubber bushings on the calipers with the bronze bushings. Nor will it be as inexpensive. This is a BBK approach.
For those with stock brakes who wish to try the bronze bushing approach, you can get them at www.bimmerworld.com. Keep in mind that you will need to lubricate and inspect the floating caliper guide bolts regularly, as they become wear items now. You can expect about another 1/16" pedal throw reduction under hard braking, similar to what you would get from installing stainless steel braided lines.
Sounds very interesting Dave, can't wait to hear what you've got.DZeckhausen said:
Having installed a Brembo BBK, I'd say it has much better bite and pedal feel than stock, but still not same immediate and linear feel as my 930 Porsche, so would be interested in what else you come up with.
Cheers!
I had the same problem with my beast.No matter how my times the dealership bleed my brakes we were never able to achieve a firm solid brake pedal like the one in my M3.I test drove a few other M5's with stock brakes and they all had a similar feel of extra pedal travel than normal before the brakes kicked in.I'm begining to think its a trait of the M5 braking system.a_ok2me said:
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The M5 will never have the same pedal feel as the M3, regardless of how well you bleed those brakes. That is, unless you install the StopTech 4-wheel BBK.M5HP said:
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A careful review of my M5 web page will reveal the formerly secret development project: http://www.zeckhausen.com/BMW/E39_M5.htm. Hint: Check out the StopTech big brake kit offerings for the M5.DZeckhausen said:
Those of you with a front-only StopTech kit will now have a rear upgrade solution that can be added without having to change your front calipers. Those who have been avoiding big brake kits completely becuase you can't retain your stock wheels without using spacers will now have a 4-wheel upgrade option that does not require any spacers. And you get to keep the factory 18" wheels!
I expect the new rear kits to become available in about three weeks. I get the first production model to try out on my own car first.
DZeckhausen said:A careful review of my M5 web page will reveal the formerly secret development project: http://www.zeckhausen.com/BMW/E39_M5.htm. Hint: Check out the StopTech big brake kit offerings for the M5.
Those of you with a front-only StopTech kit will now have a rear upgrade solution that can be added without having to change your front calipers. Those who have been avoiding big brake kits completely becuase you can't retain your stock wheels without using spacers will now have a 4-wheel upgrade option that does not require any spacers. And you get to keep the factory 18" wheels!
I expect the new rear kits to become available in about three weeks. I get the first production model to try out on my own car first.
New larger rotor and 2 piston instead of 4 huh
Not bad.
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You scared me for a second. I went back and checked my web site to be sure I hadn't made a typo. The new rotor is actually a bit smaller. It's a 351mm x 32mm, 4mm smaller in diameter. You're right about the new 2-piston caliper. With the smaller total piston area possible by this design, it will work with the existing front-only kits and pedal feel will be even better than the original 4-piston 4-wheel kit.Jayson said:New larger rotor and 2 piston instead of 4 huh
That my friend is VERY good news indeed since I have the Stoptech BBK for only the front! Do keep me on that!DZeckhausen said:
After reading your website I noticed that the rear 13.8" brake kit is for those with the stock wheels. I have BBS CH 19" wheels on mine. Does that mean I'd be able to get the rear 14" brakes on mine? I don't see that as an option.
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