borrone821

iTrader: (3)

Hey guys,
Little background. Brake line blew on my 03 Silverado; ended up replacing all of the lines in the system. Tried bleeding and couldn't get anything to the rears. Tried this with a power bleeder and the 2 person method.

I went to the ABS block. Good fluid into both ports. Good fluid out of both fronts. I cracked the rear output (top right) and am getting nothing. Completely disconnected it and there is no output at all.

Like an idiot, I went to the dealership thinking they could cycle the ABS to get fluid moving. They told me I need a new BPMV and there were NO codes getting thrown by the ECBM. Neither my brake light nor ABS light are on.

I brought it home instead of paying them $800 to throw parts at it. I pulled off the ABS module and am waiting for the Liquid Wrench to soak before pulling the ECBM from the BPMV.
I'm assuming the ECBM is good since it's throwing no codes and when the car is off, shoudn't be controlling the valve openings.

Is there a way to test the BPMV?

Thanks
Jim

borrone821

iTrader: (3)

OK so I pulled apart the ABS module, blew some compressed air from the rear input, got nothing out of the rear output. Air into the front input, air out of the two front outputs. I pulled off the motor and wiggled the 2 pistons and pressed in the rear. As soon as I did that, I tried again. Air started flowing through the rear. I put the motor back in, and tried blowing air through. The rear seems to be working fine now. Can someone explain to me how this works and what a typical failure mode would be? I'm debating whether to put it back in my truck and try to bleed the brakes again, but don't want to bother if it's just going to fail again or start spitting out ABS codes. Any and all help would be greatly appreciated.

Jim

trans_am7935

iTrader: (15)

The only thing i could think of is that nobody bled the brakes in a long time, or activated the ABS to cycle the bad fluid out of it. I bleed my brakes every 1-2 years, depending on how much i drive, then i "cycle" the abs at least once a year by activating them on the street, this ensures fluid flow says constant and the module does not get gunked up.

borrone821

iTrader: (3)

Is there a way to rebuild it or test it to check if its bad?
Rockauto has them for 150, but if it's just pulling it apart and resetting something, i'd much rather do that...

slowpoke96z28

iTrader: (2)

I can't remember if there was an auto bleed we could do with the tech 2 on the 03 trucks.

leadfoot4

iTrader: (1)

I don't know if this applies to a Silverado, but it might be worth a try....My wife's former car was a Lincoln LS, and like "trans am7935" does with his car, I'd flush the LS's fluid every year or so. However, I couldn't get the ABS block to flow fluid to the rear calipers unless the ignition was in the "on" position.