So I have the dreaded spongy brake pedal. I replaced the MC knowing it was bad due to a sinking pedal, but still a big softy. While bleeding/purging the lines in the rear I could hear a "squirting" noise from the dump valve (the valve on the frame rail with wires connected??). The fluid looked aerated from the rear, which to me accompanies that sound. Could the dump valve be malfunctioning? The ABS seems to work during a panic stop, but I would like a firmer pedal. Is there a proper procedure to bleed the system versus the conventional way? Do I bleed the dump valve first, then the cylinders? I plan on replacing the soft lines because they have been culprits on many other vehicles in the past but...
Thanks, Mike

 

Could you fill out your sig, please?

 

bleed again!....do u have drums/shoes or disks in the back?? if drums then u need to adjust ur rears

ps did u bench bleed the MC before installing it?

 

I did bench bleed, but I had to replace a hard line to the rear so there was a considerable amount of air in the system. Could there be something related to that in the dump valve? Should I have disabled the ABS before bleeding? I will bleed again tonight.

 

just bleed again and again if needed...adjsuting rears will firm up brakes considerably for most people

 

You bleed in this order: RWAL valve (small bleeder between the lines going to it), Right Rear, Left Rear, Right Front, Left Front. Or, you can bypass the RWAL altogether and get a firm pedal that way. Much cheaper than a new module/ dump valve, and better braking if you grew up in the days before ABS.

Daniel

 

Twas the dump valve...