Hello everybody! I really need so help with my D2 brakes. They are driving me crazy!
So, I had this spongy pedal and a grinding sound and pulsation when braking suddenly at about 30mph. Also notice two of the calipers pistons were getting stuck and when braking the vehicle would pull to the right.
I replaced the MC, all of the calipers, pads, rotors and brake lines. I bled the system the traditional way and with the scanner. They were working awesome until last week.
The pedal travels all the way to the bottom when the engine is on and it doesn't seem to hold pressure (no matter how much I pump it, it won't get stiff) I don't hear any air leak in the engine bay or vacuum lines. When the engine is off it would get stiff, but not like before and it travels almost all the way down. I am not loosing any fluid and I used DOT4.
Because of this, I replaced the booster (used) and vacuum line to the intake, but it didn't really help . Two of the brakes (driver and passenger rear) are getting hotter that the other two and it pulls to the right again. It seems it's only braking with two of the wheels and I have this pulsation feeling on the pedal again when braking rough (not sure if it's the module working).
I can't keep my cool anymore with all the work I have put into it and the only things for me to change are the module and lines that run from the module to the wheels.
Any help would be appreciated!
PS: I am not getting the 3 amigos or warning light.

 

If it’s pulling it means the calipers are seized or adding braking power check your lines for any kinks etc

 

1) you say you replaced all of the brake lines...you mean the caliper flex hoses, or ALL of the brake lines (ie: the metal ones? rusty lines internally?)
2) pedal to floor is either air in the system or bad MC seal or wrong diameter MC piston.. But you say you are not losing fluid, So I guess air in system
3) ABS modulator can have air. When I replace the MC, I bleed the 2 MC lines at the ABS unit by cracking the lines at the ABS unit, and having someone else step on pedal, then I go on to bleed everything else. I think the DII braking system sucks overall. I have bled this system with 2 liters of brake fluid and still spit small air bubbles out the rear calipers!

when you fell the pulsing, do you hear the abs pump going? replaced the calipers, but did you replace the sliding pins/mounts?

Any brake /abs codes?

 

1) I just replaced the fkex lines..
2) I will do another bleed and power bleed and see if I get any improvement.
3)When I replaced the MC I bench bleed it a long with the lines.
I am not sure I can hear the pump and it seems wheels get locked.
I replaced sliding pins and hardware I also greased them. The only thing I didn't replaced were the brackets, but I did cleaned them deeply, specially where the pin goes.
I don't have any ABS lights, but I will scan my system today and see what's in the memory.
Thank you for the help!

 

the ABS unit is supposed to be a 'through unit' meaning no way for it to get fluid 'stuck' causing brake loss.... so It's unlikely to be the ABS unit unless it leaks or is showing codes...or is somehow corroded inside. Line corrosion another thought..if H2O got into master reservoir...

pulling or overuse may be a sign of air in one system of the 'X'.......or a bad rebuilt caliper...or bad suspension component....but less likely...

I had a pull left for two years...did everything..couldn't find the issue...but i think it may have been a bent frame as the front torsion bar on left was bent in about an inch (prior accident!)...got rid of that DII...so frustrating!