E320 cdi front brakes
 

Hey guys.

I was changing my front brake pads like I have many times before. I pushed in the piston on the caliper and removed the old brake pads. I found that Autozone had given me the wrong brake pads so I proceeded to reinstall the old brake pads, and they were pretty worn. When I stepped on the brake pedal the piston would only come out half the distance and the red brake light came on. My question is do I need a new caliper or should I try installing the new pads and see if the red brake warning light goes out?

As always thank you in advance for your replies

What year is the car? If it has the SDS braking system you need to disconnect the harness at the brake module before doing anything to the brakes.

It is a 2005

Don't you just pump it a few times so the pads adjust to where they should be.

2005 E320 CDI is an SBC brake car, changing brake pads on it is not like other cars and the OP is lucky to have all fingers left.

If the correct tool to put the SBC into service mode is not available then there is a manual bypass that involves raising the car perfectly level, spinning a sequence of the wheels, rolling down the driver window and locking the car for 10 minutes to get (or something like that) to disable SBC. In this mode you can push the pistons back in.

To reenable the SBC there is another sequence which is then affirmed by the brake lamps flashing. This enables the SBC to advance the pistons out and the system tests by stopping each wheel as the mechanic turns it while on jacks.

OR

you use a scan tool to disable the SBC or remove the connector (which can make you require the MB scanner to reenable the SBC)

It is also mandatory for flushing the brake fluid.

basically its the same idea as if you are working on Toyota Prius/Lexus LS, LX or Land Cruiser brakes.

I have changed my brake pads a few times without any problems so I am not really understanding this. Could it be that just the caliper is defective?

You forgot to mention that you have to hop on one foot for 3 minutes. The SBC system isn't that scary. When it first came out, we were all disabling it with the SDS. Then just unplugging the pump. Now, after doing it 100s of times, you simply shut the door, remove the key and let the car go to sleep. The cluster will go dark. Then you can preform all the brake work you would like. No need to pump the pedal when you're done. Just open the door to wake up the car or turn on the key. the pump will come on and do the rest.

So, my question is, if I install the new brake pads and start the car, will the pump make the proper adjustments to the piston on the caliper without me hitting the brake pedal?

That is the way I read it.

Hey guys, I recieved the right brake pads and installed them, started the car and the pump adjusted them just like you told me!.... Thanks for all.of the great help!!!!

Now you just have to do the left brakes!