[Bigwill]

ON-VEHICLE SERVICE
When I recently installed my new PowerBrake disks and pads I decided to also change the brake fluid on my Gen3 DiD. I suspect that I pulled air into the rear circuit during the bleeding process because the back compartment of the reservoir is largely out of site and it went very low. I continued with the bleeding process at each wheel a number of times thereafter. However I am not happy with the pedal height and it feels rather spongy IMHO. I cannot recall that it was like that before. For anyone else it may feel normal. Car is still stopping well. Then I read the manual and found this. (See below) Apparently there is a very specialized procedure to bleed the air out of the ABS components. I was hoping that normal ABS engagement may circulate the fluid in such a way that it will bleed itself.

TSB Revision
BASIC BRAKE SYSTEM 35A-125
CAUTION
When connecting or disconnecting the scan tool, ensure
that the ignition switch is at the "LOCK" (OFF) position.
(1) Turn the ignition switch to the "LOCK" (OFF) position and
connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position. Select from
scan tool menu screen as follows:
[SYSTEM SELECT →ABS →ACTUATOR TEST →AIR
BLEED]
(3) Depress and hold the brake pedal.
(4) Activate the actuator test [AIR BLEED (1)]. When the
scan tool flashes confirmation that the AIR BLEED (1)
operation is completed, proceed with AIR BLEED (2).
(5) Depress and hold the brake pedal.
(6) Select and activate [AIR BLEED (2)] on the scan tool
screen. When the scan tool flashes confirmation that the
AIR BLEED (2) operation is completed, go to step 7.
The difference I feel in the pedal may also be because of the new pads especially the rear ones which went onto used discs and not new ones like the front. Am hoping for improvement as it works itself in.
I would appreciate any comments from my fellow members. Especially a workaround that special tool MB991502 that is mensioned.

[paw_by_paw]

Bigwill,
For assurance try and bleed the furthest caliper from brake booster first and see if there is bubbles coming out.
Maybe it will solve your problem. I had all my calipers removed to service and installed with the regular bleeding process and no problems. Unless your system sucks in air somewhere.
I doubt if new brake shoes and discs will cause spongy effect but maybe they should run in first as described by power brake.

[Bigwill]

Thanks for your reply Paw, it is satisfying to know that you managed the job with only the standard bleeding process. As I said my brakes are fine, but having readup the Mitsu bleeding process I think I started imagining things that is not really a problem.

I suspect that the new rear pads were initially catching on the outer edge of the discs only as the discs are slightly worn round and the pads does not seat properly. I normally round off the square corners of the pad with a grinder but neglegted to do so this time.

The good news is I think that the pedal thing is improving allready. Since your reply I am now even more convinced of this.

[4ePikanini]

try bleeding with the engine running as the gen3 has an electric vacuum booster.

[Bigwill]

Thanks for another suggestion. However I did have the ignition switched on without starting the engine. This way the pump runs aswell.

[4ePikanini]

Thanks for another suggestion. However I did have the ignition switched on without starting the engine. This way the pump runs aswell.

Only for a limited amount of cycles. It will be better if the engine is running. Just beware of the exhaust gasses.