NNBS brake job done - pedal not firm

[4WDTRK]

Finally did a full brake job (front and rear) with new calipers, rotors, pads, and stainless braided hoses (all six). The fronts got changed to the larger 07+ calipers/rotors.

I bled the entire system refilling with fresh fluid. Test driving does not feel firm like I was expecting. I'm thinking a second bleed is probably necessary after driving and seating the pads. Must still be some air in the system. Anyone have any experience with this? Thanks!

 

[MassHoe04]

Was the fluid checked and topped off to the proper level (if needed) after working the brakes some? If the pads hang up, they can keep the pistons from extending. Then when the pads finally seat, the pistons extend further than they did before, dropping the fluid level in the reservoir.

I did not have a power bleeder when I did mine. I just pumped the pedal to build pressure, then opened the bleed valve. The first time was soft, but after a few more repeats of the pump and bleed... Pedal feel improved. Felt fine to me after that. Brakes work great.

I would go through the process of working the brakes in. A few good stomps on the pedal to seat everything real good. Then, check the fluid level and top of it more is needed in the reservoir.

 

[4WDTRK]

Everything was topped up, but in my case I didn't touch the pedal until after the bleed. I did the rear axle, bleed, and test drive, then the front axle the next day.

I have a feeling things will improve after another 4 corner bleed.

 

[corvette744]

Everything was topped up, but in my case I didn't touch the pedal until after the bleed. I did the rear axle, bleed, and test drive, then the front axle the next day.

I have a feeling things will improve after another 4 corner ble

Everything was topped up, but in my case I didn't touch the pedal until after the bleed. I did the rear axle, bleed, and test drive, then the front axle the next day.

I have a feeling things will improve after another 4 corner bleed.

You definitely have air in the system.Especially with new stainless lines it will feel so much harder than the rubber junk.Keep bleeding possible you will have to activate the abs pump if air is stuck in their.I would also pressure test the system and make sure nothing is seeping.

 

[4WDTRK]

Yea it's not even close to feeling 'hard'. The power bleeder essentially does a pressure test at 15psi, I've checked all fittings several times and all look good. Might not be able to bleed until end of the week. I'll report back. Thanks!

 

[89Suburban]

Find a slick dirt or gravel road you can slam the brakes on and make the ABS kick on and cycle a few times then try 4 corner bleeding again.

 

[4WDTRK]

I really don't think I got air in the ABS module, but you never know. Slamming the brakes in the dirt sounds like fun though!

 

[89Suburban]

I really don't think I got air in the ABS module, but you never know. Slamming the brakes in the dirt sounds like fun though!

One other thing to note FWIW. If you have high mileage worn rear the axle shafts move in and out and that causes the rear calipers to spread open some requiring a double pump to bring pedal back up to where you expect it.

 

[rockola1971]

You cant bleed the brakes on our K chassis the old way like we did in the 70-80's. You must have a bi directional scanner like the Tech II to actuate the valving in the ABS valvebody. There are solenoid valves that have to be actuated in order to get all the air out that is upstream and downstream of the ABS Valve body. The Tech II actually has one man Brake Bleed function built in. Its great and works awesome too! It uses the ABS system to pump the brakes for you. Ive been across this bridge before and its the reason why I bought my Tech II clone years ago.

 

[4WDTRK]

You cant bleed the brakes on our K chassis the old way like we did in the 70-80's. You must have a bi directional scanner like the Tech II to actuate the valving in the ABS valvebody. There are solenoid valves that have to be actuated in order to get all the air out that is upstream and downstream of the ABS Valve body. The Tech II actually has one man Brake Bleed function built in. Its great and works awesome too! It uses the ABS system to pump the brakes for you. Ive been across this bridge before and its the reason why I bought my Tech II clone years ago.

Good info thanks! Would this tool only be necessary if air somehow got into the ABS module or part of the ABS was serviced? For hose and caliper changes shouldn't I be good to go?