Brakes issue - need your advice - The Unofficial BMW M5 Messageboard (m5board.com)

Andrey///M5 · 24th May 2005, 16:04

Hello to everybody reading

I have M5 e39 with the stock brakes and never have been satisfyed by these brakes.
As i found out, AP Racing brake kit is the cheapest option i can find here, and i almost have no chance to find Brembos at the same time/place.
Does anybody have ze experience with AP Racing brakes? Can anyone compare these brakes with Brembo?

And also i would like to know whether the solution exists for suspension upgrade in order to let E39 to be driven as good as E34

We have actually some special conditions here in terms of auto business, and this is why i am asking for your good advice, not many M5s are driven here and not much experience to exchange.

Thank you in advance,
Andrey
M5 E39 (young wife)
M5 E34 (lovely wife)

jordantii · 24th May 2005, 19:06

AP may be better than Brembo. They are at least in the same league. Make sure they have dust boots on the pistons to keep dirt out.

Jordan

DavidS · 24th May 2005, 19:58

Andrey,

I am no brake expert, but if think the AP breakes are very good.
Check out Zeckhausen Racing among the board sponsors.

BTW are you sure the stock brakes are ok? Maybe there is a need to
bleed the DSC unit. See:

Soft Brake Pedal - Bleeding tricks?

David

bmwusa · 24th May 2005, 20:25

Just curious, how much are the AP brakes compared to Brembo? Josh

foxyboym5 · 24th May 2005, 22:20

Dont rule out stoptech - theyre excellent too, and can fit 355mm discs under stock front wheels and are great value for money

do a search on the board - you'll be here all night!!
cheers

Andrey///M5 · 25th May 2005, 12:43

Thanks to all of you, guyz!

I have read through some threads you noticed - and have to clarify something:
i have firm enough brake pedal, but i am not at all satisfied with braking intensivity (braking acceleration? not sure about the right term) when i have to brake from 180 km/h and higher speed - it brakes very slowly (in my personal opinion), while lower speeds are quite acceptable for braking generally. Thus i would suggest that i don't need bleeding out the brake system, but have to upgrade the brakes somehow.
I use original brake padz only - does not anybody think that this problem may be solved by simple replacing of the brake pads?

As for AP Racing brakes - well, i yesterday misunderstood local AP dealer and as it is appeared, there is the price of usd3200 for front brakes only, what actually makes them quite expensive for all wheelz...

Good luck

foxyboym5 · 25th May 2005, 12:55

Quote:

Originally Posted by Andrey///M5

Thanks to all of you, guyz!

I have read through some threads you noticed - and have to clarify something:
i have firm enough brake pedal, but i am not at all satisfied with braking intensivity (braking acceleration? not sure about the right term) when i have to brake from 180 km/h and higher speed - it brakes very slowly (in my personal opinion), while lower speeds are quite acceptable for braking generally. Thus i would suggest that i don't need bleeding out the brake system, but have to upgrade the brakes somehow.
I use original brake padz only - does not anybody think that this problem may be solved by simple replacing of the brake pads?

As for AP Racing brakes - well, i yesterday misunderstood local AP dealer and as it is appeared, there is the price of usd3200 for front brakes only, what actually makes them quite expensive for all wheelz...

Good luck

Most of the braking is done on the front as the weight shifts there when decelerating, so 4 wheel system is not really necessary. One of the selling points of the stoptech is that it is well balanced when using stock rears.

Brake pads will make a difference i believe, but more to heat issues than actual ******ation.

I'll leave the tech stuff to Dave Zeckhausen!!

Do a search for Dave's posts and you'll learn loads about brakes etc.
cheers

DavidS · 25th May 2005, 13:11

Andrey,

Have you driven another E39 M5 to compare yours with?

Have a look at your rear rotors. Are those a little less shiny than the front ones? More black spots?

If you drive at 20 MPH and rapidly step as hard as you can on the brake pedal, the car should get into ABS regulation on both front and rear wheels immediately and stop extremely fast.

If you drive at 20 MPH in reverse and step as hard as you can on the brake pedal, the car should act the same.

If the braking when going in reverse is weaker than when going forward there may be a problem with the rear brakes, or with the brake force distribution regulator.

David

Andrey///M5 · 25th May 2005, 16:46

DavidS,
Thank you for your advise, will try to check brake distribution the way you discribed

And will let you know, or will apply directly to Dave Z.,
Thank you anyway,
Good luck

NAT · 25th May 2005, 17:47

I have to say that i find exactly the same deficiency with my brakes as well , and i am considering an upgrade but dont know what to get and i definetely want to keep the standard wheels.
At speeds below 80 MPH the brakes are very adequate , however the other day i had to stop from 130 MPH and i have to say i didnt think i was going to stop...........there was no feel , no bite and i can only describe the feeling being the same as the feeling you get when your brakes have overheated ( and mine hadnt ). All my components have been checked recently and everything is in good working order. I do think its just the way they are ...............anyone care to differ/comment ?

Quote:

Originally Posted by Andrey///M5

DavidS,
Thank you for your advise, will try to check brake distribution the way you discribed

And will let you know, or will apply directly to Dave Z.,
Thank you anyway,
Good luck