Should the engine should running or turn the ignition on while bleeding the brakes?
 

I read somewhere that the engine should running or turn the ignition on while bleeding the brakes. Is that true for my 1994 Mercedes E320 wagon with ABS and ASR traction? Comments, advice or feedback is greatly appreciated.

I have never heard that and i have had 3 W124's that i have done my own brake jobs. I have two E320's and bleed the brakes with everything off.

HGV, thank you for posting your comments. I appreciated it. Any others out there to comment as well?

This is my understanding, use it at your own risk.

Start the car AFTER doing a complete wheel bleed, remove the black plastic cover on the ASR unit, put a hose on the ASR bleeder directed into a catch can. With the car running allow the fluid to run clear and bubble free from the ASR and close the nipple, shut the car off. Refill and recap the reservoir. Don't let the master cylinder run dry at anytime while bleeding the system.

Good luck!!!

Hey Sugar Bear, great to hear from you. I ordered the Motive Products - 0100 European Power Brake Bleeder Kit earlier today. Should be a big improvement over the vacuum brake breeder I used earlier.

Where is the ASR bleeder SP on the hydraulic control unit ?
 

On the Hydraulic Control Unit as shown in the picture below, it seems to me that the Hydraulic control unit consisted of ABS and ASR unit together. I only find the SP on the ABS unit. See the red circle on the picture below. Is there another SP on the ASR Unit or does this one SP take care of both ABS and ASR together?
I also include two instructions on ABS/ASR bleeding the unit. It only shows one SP. So I assumed the SP take care of both ABS/ASR hydraulic Control Unit. Does the pre charged ASR pump located below the Master Brake Cyclinder have a SP or does it need to bleed as well?

Comments, advice, feedback is greatly appreciated.

brake bleeding using Motive Product 0100 pressure bleeder, left front brake caliper
 

brake bleeding using Motive Product 0100 pressure bleeder, left front brake caliper bleeder valve, no brake fluid coming out.


Using the Motive Product 0100 pressure bleeder, european style, for the first time ever works rather well. Going through the motions of right rear, left rear, right front and left front brakes caliper in order of seequences. The first three brake bleeding locations went well. Lots of dirty fluid and air bubbles were coming out. When brake bleeding the left front caliber, after loosening the bleeder screw, no brake fluid came out at all!! Brake pedal traction was a little spongy afterwards, however, the brake pedal firmly stop above about 3 inches from the brake pedal floor.

What could go wrong trying to bleed the front left brake caliper and no brake fluid coming out? Is the brake caliper going bad? What about the brake line? I am somewhat baffle by this issue. Can anyone out there tell me what is the problem? Any comments, advice, feedback is greatly appreciated.

Could be a clogged bleeder screw. Check to be CERTAIN the reservoir didn't run dry, look closely in the front AND the back of the reservoir.

Good luck!!!

The issue with the no brake fluid coming out of the brake line is also on the post:

http://www.peachparts.com/shopforum/tech-help/414638-brake-booster-push-rod-felled-out-4.html#post4230368

Update: Front left side brake line, no brake fluid coming through at all.

I did a process of elimination by doing several different methods to determine why the brake fluid is not coming out of front left brake line.

I checked for brake fluid level on the reservoir above the master brake cylinder. Both sides of the wall/dam of the brake fluid reservoir are full.

I removed the brake bleeder screw/valve on the front left side brake caliper (facing left on the driver's side). I checked for blockage by blowing air inside the bleeder screw. Air came through on both sides clearly. Next, I removed the brake hose from the brake caliper to the brake line connection. Again, I blewed inside both ends of the brake hose, all clear, no blockage on the brake hose.

I proceed to use the Motive Pressure bleeder on the reservoir above the master brake cylinder and connected with a transparent plastic hose on the brake line. No movement of brake fluid coming out of the brake line.

I removed the Motive Pressure bleeder from the reservoir and put the cap back on the reservoir.

I started the engine and wait for a minute to build up pressure on the ABS module. I pressed the brake pedal several times and good solid traction, not spongy-like feel and stopped about 3 inches above the brake pedal floor. No brake fluid came out of the front left brake line after pressing the brake pedal.

Something is blocking the brake line from getting the brake fluid to flow out. Broken Brake line? Leaking Brake Line?

Next, I will use the vacuum brake pump and connect it to the front left brake line that was disconnected from the brake hose, and see how that work. If that does not doing anything at all, that is, no brake fluid coming through the brake line, what next? Any ideas, comments and/or advice is greatly appreciated. I will continue to follow up on this mystery. Stay tune.

Sugar Bear, thank you for your last post. I appreciated it.

my 99 w140 bleed like any car