Hoping someone doesnt just pass over this as ANOTHER 3 Amigos question. THough it is just that I am trying to figure out with nanocom.

Ok, 03 HSE7 with the migos. Has REALLY hard brake pedal. When i bought it from the guy he handed me the history and I found that the most recent repair order stated it needed a brake booster (has BRAND new master cylinder from PO) so i installed. Still has hard pedal. I ordered the nanocom (figured it was long overdue since I have 3 of these now) and i hooked it up with no ABS fault codes.

Is there some diagnostics I should be looking at to determine what to fix?

Not just wanting to throw money at parts and not have a clear path to solve issue. Keep gettting told it is the full blown ABS unit rebuild needed. Would like to know concrete before I do that.

THanks guys

 

Take to it a brake shop and get it diagnosed as to what is actually wrong, you don't want to guess or take the OP's opinion on what was messed up. Even 3 amigos will not cause a rock hard pedal.

My bet is you have a vacuum problem but that an be a pain to sort out.

 

I agree on the vacuum but i replaced the booster vacuum line with the booster and tested suction and it was good

 

Does the pedal stay hard while the engine is running and/or engine off? Also check that your gas pedal goes to the floor, sometimes when reinstalling the master, the master cylinder rod doesn't slide into the cup on the brake lever assembly. One way to tell if this might have happened is to check the accel pedal has full travel. If it binds, i'd go back and check that and confirm the oring on the master to vacuum booster didn't slip off or get misplaced.