Brake pedal goes to the floor after new shoes

[SUBURBAN5]

Meaning this little guy. This is technically not the right tool but can be used to help bleed the combination valve

 

[97c1500ext]

What was the original problem? As there is no load on the raised wheels, your spinning them up and then braking tells some braking pressure is there, but nothing else. Very little brake pressure will stop the raised wheels. Activating the brakes with drums removed risk blowing out brake cylinders.
Bench bleed mas/ cylinder, very thoroughly? Replacement M/C is verified correct unit? What method to bleed brakes?

The MC was the only option from Rockauto for my make model and year that was ACdelco and looks identical to the previous MC. I may not have perfectly bled the MC since i dont have the kit with lines running back to the reservoir and it was squirting pretty strongly from the forward fitting and weeping from the rear. There is a chance a small amount of air could be still present and i will be attempting to bleed it while on the truck later today. I bled the lines first with a vaccum bleeder then by openning the bleeder while someone pumps up then holds the brake pedal.

 

[97c1500ext]

Meaning this little guy. This is technically not the right tool but can be used to help bleed the combination valve

I bled the combination valve with a screwdriver on that button and someone working the pedal. Only got strong fluid spray with little or no air

 

[97c1500ext]

What was the original problem? As there is no load on the raised wheels, your spinning them up and then braking tells some braking pressure is there, but nothing else. Very little brake pressure will stop the raised wheels. Activating the brakes with drums removed risk blowing out brake cylinders.
Bench bleed mas/ cylinder, very thoroughly? Replacement M/C is verified correct unit? What method to bleed brakes?

The original problem was i was going to do pads and shoes because i was getting some vibration in the steering when braking under certain conditions and was started to hear a bang occasionally when letting off the brake. I was fairly convinced it was time for new pads and shoes anyway.

 

[SUBURBAN5]

Ok if it was me. I would bleed rear to front again. Confirm your getting good flowing brake fluid. And if all wheels yes. Then I would have to bleed the abs module per gm procedure... all of this is assuming nothing wrong with the drums or brake hardware.

Btw what brake code do you have jb5?

 

[97c1500ext]

Ok if it was me. I would bleed rear to front again. Confirm your getting good flowing brake fluid. And if all wheels yes. Then I would have to bleed the abs module per gm procedure... all of this is assuming nothing wrong with the drums or brake hardware.

Btw what brake code do you have jb5?

Not sure of the code but they are the dreaded 10in drums in the rear and disc in front. Being a 97 i also have the 4 wheel ABS.

 

[97c1500ext]

Ok if it was me. I would bleed rear to front again. Confirm your getting good flowing brake fluid. And if all wheels yes. Then I would have to bleed the abs module per gm procedure... all of this is assuming nothing wrong with the drums or brake hardware.

Btw what brake code do you have jb5?

The last thing i did before giving up for the night was attempting to pressure bleed in the rr rl fr fl pattern furthest to closest.

 

[SUBURBAN5]

Not sure of the code but they are the dreaded 10in drums in the rear and disc in front. Being a 97 i also have the 4 wheel ABS.

You have jb5 more than likely. Not a difference as far as procedure. But yeah most people complain about the braking performance

 

[97c1500ext]

Awesome just want to clarify because bleeding can be a pain with these systems. Bleeding the mc was important. Did you bleed from the mc to the module, then bleed out the module, then bleed from furthest wheel to close wheel to mc? If all checks and bled right meaning via 2 person or a vacuum brake bleeder , then you would still have to bleed the abs module after all that.... the combination valve you asked about if determining a difference in pressure . If you bleed the brakes and the middle valve moved, your only bleeding front or rear depending of the pressure difference.

I bench bled the mc, installed then pressure bled from rr rl fr fl furtherest to closest, bled the combo, then re-bled each wheel in the same pattern. Never got much air from anything

 

[97c1500ext]

You have jb5 more than likely. Not a difference as far as procedure. But yeah most people complain about the braking performance

I didnt have a complaint beyond the recently developed stuttering, i dont carry any weight so it stopped just fine and the pedal wasnt what ive seen some people complain about. The stuttering wasnt consistently all the time so that is one reason i thought there might be something else failing and not warped rotors. The MC had been changed by my dad when he originally got the truck a few years back and im fairly sure he never bled the ABS and the brakes felt fine. Squishier than his 02 1500HD but I dont think that would surprise anyone.