Hi guys,

I'm very happy w/ my E55 braking power, but there's one issue i'm not too happy with - the first 1/2" of brake pedal travel is very soft, as if it doesn't do anything. then the brakes grab very suddently.

the MB svc advisor says it's due to large rotors and pads grabbing quickly.
that may explain the sudden grab, but certainly it doesn't explain the 1/2" of pedal travel.

now my new MB indep guy is saying my front rotors are 1/4" thinner than new and thus explains the travel. this pedal travel is softer than my W210 E320 wagon or the E320 Cabriolet which are both firmer. i did drive one other E55 recently and it seemed soft in the first inch of travel as well.

p.s. the firmest/most linear brake feel i've had was my old 1995 525i w/ cross drilled brakes and new brake lines/fluid. the prior owner said that was the reason for the firm feel.

you guys have any thoughts here?

 

That's exactly how my brakes are. You press press and press, don't feel anything.. until you press a little more, then BAM your brakes kick in hard! ROFLMFAO. First day of driving my E55, I looked like an idiot braking. ROFL, I got the hang of it tho. Gotta love the big brakes!

 

you should flush out your old brake fluid & bleed the lines if you haven't done so. You should do it every year. Water & air = trouble!
Power bleeder is about $55. Well worth the investment. First thing I did to my brake systems when I got my car is to flush the whole system with new fluid. Make a big different

 

So your saying that our brakes aren't supposed to be like this? ... I thought it was normal.

 

The brakes on my car are very smooth and predictable (they seem to defy physics stopping the beast on demand) - have to agree with the recommendation for brake fluid flush.

 

Grrr, so much stuff to fix on the car. LOL, I got to give it the 60k service, spark plugs (wires also, if needed), new rear wheel bushing(s), 4 new tires, new pieces on the front windshield (the rubbery stuff thats known for cracking), cigarette lighter doesn't work, the car needs floormats (didn't come with any), new tints w/ that spacer so it doesn't scratch my tints, and if you wanna top it off.. I want to re-dip my rims in chrome because they are chipping already. All of this sounds like a mission. I'll throw in a new MAF too just for fun. haha jk. ROFLMFAO.

 

i just talked w/ mechanic again...he says it's a good thing to do and he doesn't mind doing it for $65, but maintained that he didn't think it would affect the brake feel, that in his opinion my front rotors are 1/4" inch thin and that was the cause.

 

...so to get new front rotors, is it true only OEM discs allowed and they're $240 each...now x 2?

 

Not sure about this as my brakes are brand new, and I experience exactly the same thing as you do. 1/2 travel soft, then bam, super brakes!

There was another thread on here about guys doing the power flush and exchanging the normal brake lines for Stainless Steel Braided brake lines. I believe that was supposed to improve pedal feel by a good amount.

The SS line were supposed to be about $150, which isn't too bad.

 

I did ss lines and flush, totally changed the brake feel for the better. I used Stoptech lines and they are solid a month after I installed with no leaks or issues.

 

The E55's brakes feels the same in all cars (My car too), one point is the BAS system (your mechanic can explain you how work, & he can make you a sample function activation with the HHT of the system & you go to understand why the brakes in this cars apply to hard) "But the BAS system don't work in a normal braking condition", the other cause YES the big rotors make full difference between the 320's 420's 430's all non amg's, & the other point is the BIG pads used in the amg 210's, have a big contact zone & result in a hard braking power.. Any way i don't think that the weared discs cause this symptom. try with some flush & brake liquid change

Like to hear about that inform us about any change please!

Thanks in advance friend

Fabio Daniel

 

Your tech is correct ANY Undersize Brake Rotor WILL cause a soft Brake pedal

When I Worked for Mercedes I Saw this complaint a Lot!

If the front rotors are worn a 1/4 from stock they are worn out

Replace them with a set of low dust aftermarket pads ad a set of braided brake flex hoses...and renew the fluid

 

next time you know you'll brake, try double tapping the pedal, you'll notice on the second push your pedal will be instant no delay
like Mark said, front rotors might be worn and need of a flush

 

Why would worn brake rotors cause a soft pedal feel?
Correct me if I'm wrong but don't the brake pistons constantly adjust for rotor wear so there should be no change in pedal "feel".
The only difference is that the brake fluid level should go down because the piston is moving further out.

In regards to the brake flush it's always a good idea if it hasn't been done in awhile. And pressure bleed, don't use the old method of pumping the brake pedal. Bad idea.
Use good fluid, Ate Gold or Super Blue or similar.

 

TRUE, and here is a good read,
https://mbworld.org/forums/w210-amg/...-question.html
If you have over a half inch of free travel in the pedal and an "on all of a sudden" brake you have air in the lines they must be bled and don't do as I did.

 

The Pedal feel and travel IS affected with Worn Pads and Rotors
if the rotors have a huge lip on the them the pads will wear in with little pad area touching...that requires more pedal effort to stop and results in a soft brake pedal....Take a look at a worn set of brake rotors and see the total pad area as worn rotors will have lips/edges at the top and bottom of the rotor surface ....This is also why after a brake job the pedal is solid

As the pads are not in contact with the rotors unlike a SBC car.. =Pedal travel

 

Mark,
Sorry, I've got to disagree with you on this one.
Actually, the reason why many times your brake pedal will feel more solid after a brake change is that you're pushing the pistons back into the cylinder therefore you've got less fluid (and probably some water and air along with that) in the cylinder to compress. Also, many times after a brake job the mechanic will and should bleed the system eliminating the crappy old fluid and moisture/air with it and consequently you've got a firmer brake pedal.
A new brake set up will actually have less pad touching the rotor than a worn one will because most pads (not all) are designed to gradually bed themselves into the rotor.
The ridges you see in the rotor is from areas of the pad that don't contact the rotor, not because there's less contact area between rotor and pad.
Dean

 

+1 , this is the best thing you can do for brake "feel". Stoptech lines are the strongest & safest lines on the market, I wouldn't trust any other manf, especially ebay & goodrich, both have been prone to failure.

 

you wouldn't trust Goodridge? what?
they make good lines, quality products. used in every type of application, i've been using them for couple years on bikes too no issues; and it's #1 brand picked by bikes enthusiasts that race, race and race, not this silly parking lot getherings and pose, but track, track and track.

 

+1 , All Brembo kits come with Goodridge brake lines, if there was any failure history for goodridge I would think that Brembo would have any different lines with their kits, or brand their own.

 

If you do a search on this forum and a few others you will see that Goodrich lines have failed in the past, where as stoptechs have not. You can still use them if you want but I would just go ahead and get the best (stoptech).

 

Wow! I've also been a believer in Goodridge due to their great reputation with motorcycles. I guess you never know.
Maybe FrenTubo will start to make some of their brake lines for automotive applications!