Mercedes-Benz Forum - Reply to Topic
Topic: brake performance Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


  Additional Options
Miscellaneous Options

  Topic Review (Newest First)
06-17-2019 05:47 AM
pfsantos Check your brake booster and the vacuum plastic hose and connections to it from the intake manifold. The line runs over the air box around to the front of the engine.

Search youtube for "check brake booster operation" to understand the 'pedal test' with engine on and off and the response you should get when you hold the pedal and start the engine.

I was already wondering about it, and moreso now that you mentioned the AC on making it worse. Usually, the engine management adjusts idle to compensate for the additional load of the ac compressor. This usually affects the vacuum the engine produces. Only doubts I have about this being your problem are that the vacuum should not change much, and the brake booster is not a common problem on these cars AFAIK.

I'd still check the above since it's free, quick and easy, but make sure the pads/rotors/calipers/sliders/fluid are good and fresh.
06-17-2019 01:02 AM
pablo_can when the ac is on, it is getting worse. Are there any relation between ac and brakes?
06-16-2019 01:49 PM
DEVOURS I would also make sure that the caliper guides are moving in and out freely.... The brake pads should always be free and movable..along with the calipers pistons..

If anything is too tight (possible due to rust..), the brakes will not stop the car properly....

My B stops very well, but I have to keep on top of the floating parts..
06-16-2019 08:52 AM
260e crusier
Originally Posted by pablo_can View Post
I don't usually downshift cvt, I think hurting brakes seems better idea instead of hurting cvt.
Every situation is different. OP has some unknown issues with his brakes. Most modern cars should not have any problem slowing down or stopping, even under load and going down hill. It's either mechanical or driver's bad braking technique.

I was merely suggesting other options that a lot of people have forgotten today when driving cars with auto transmissions. Better to downshift or even use emergency brakes to slow car down than losing control.
06-16-2019 08:02 AM
DEVOURS Make sure that all 4 calipers are travelling in and out smoothly... You would have to remove the wheels and manually push the pistons in ( a "C" clamp is a simple way to check this..) and see if they all move in with the same effort.

Remember to protect the pistons from coming out too much if you apply the brakes with the calipers free..

For the calipers again..

If not, you might have corrosion behind the caliper piston and out of sight. One reason why we change the brake fluid on a regular basis..(usually 2 years..for the fluid..)

Let us know if you find anything..
06-15-2019 11:39 PM
Originally Posted by 260e crusier View Post
Wouldn't hurt to downshift and take some load off the brakes in that situation.
I don't usually downshift cvt, I think hurting brakes seems better idea instead of hurting cvt.
06-15-2019 09:00 PM
Mike Ti 5 speed manual and for me that's normal (double clutch to save linings and synchros) but the problem is the brakes are under used, not over used.
06-15-2019 07:25 PM
260e crusier Wouldn't hurt to downshift and take some load off the brakes in that situation.
06-15-2019 06:51 PM
Mike Ti Mine are getting to be the absolute shits too - it's nearly impossible to make the car stop hard enough to activate ABS.

They flash rust in rain and after three days of disuse they're like sandpaper and a 1924 Lea-Francis probably stops better. German discs are atrocious. Never had these issues with a Peugeot 405 in 366,000 km....

I need to buy new rear calipers, new rubber hoses (I expect) and 4 discs and maybe that will sort it out. Will do that around 300K km. Last investment in the car before she's replaced in a few years' time.
06-15-2019 02:32 PM
Black Swan Sounds like your rotors/disks may be getting over heated. Even if the pads and rotors are smooth, they can be too thin to absorb the heat properly. Another area that can effect brake performance is old contaminated fluid.

Your symptoms would suggest they need some sort of service.
This thread has more than 10 replies. Click here to review the whole thread.

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Title goes here

video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome