Excessive brake travel - Where is ASR Pump on a '98 e320 - PeachParts Mercedes-Benz Forum

mespe · #1 09-17-2013, 07:22 PM

Hey, working on my 98 E320, I have excessive pedal travel for the brakes. I started to bleed them, but very little brake fluid moved with the mighty vac.

I did the two person method, and after about 10 minutes, I got out of the RR bleeder valve an amount equal to what one press,,, release should be.

What next?

pumping the brakes builds up pressure, but as soon as the bleeder valve is open, the pedal drops and hardly any fluid comes out.

There has got to be a bit of air trapped some where in the line.

Randy · #2 09-20-2013, 08:56 AM

On my '86 420, the excessive pedal travel was caused by a failing master cylinder. when I replaced same, it was restored to proper operation.

jcyuhn · #3 09-20-2013, 10:40 AM

ABS cars have to be pressure bled, a mityvac doesn't work on them.

The ABS pump is that thing on the drivers' side directly behind the windshield washer tank. It has all the hard brake lines running to it.

I never had any trouble bleeding 210 cars using the master cylinder method. Does this car have the divided reservoir where you have to fill it all the way full before the section for the rear brakes receives any fluid? That is a common problem on the older MB cars, but I am not sure when they changed to a single chamber reservoir.

How confident are you that the master cylinder is good?

Skid Row Joe · #4 09-20-2013, 02:45 PM

Quote:

Originally Posted by jcyuhn

ABS cars have to be pressure bled, a mityvac doesn't work on them.

The ABS pump is that thing on the drivers' side directly behind the windshield washer tank. It has all the hard brake lines running to it.

I never had any trouble bleeding 210 cars using the master cylinder method. Does this car have the divided reservoir where you have to fill it all the way full before the section for the rear brakes receives any fluid? That is a common problem on the older MB cars, but I am not sure when they changed to a single chamber reservoir.

How confident are you that the master cylinder is good?

I experienced more brake pedal travel as my '99 E300 aged.

It's new owner, (my younger Brother) was advised of this when taking possession of the car. The brake pads all the way around, front rotors, ALL from MB and MB brake fluid was installed 31K miles ago, 8.5 years ago. I don't know the method that indy used in the above brake system renewal. That seems to be the when of the lower pedal engagement. Drastic? No, but increasingly concerned as the pedal travel became more evident....

My Brother did mention it to his new indy, but the indy wasn't concerned with it.

Any info here appreciated to convey.