Brake Issues on 2006

Searched a few threads but can’t seem to narrow down my issue. Did a full brake fluid flush, replaced both front calipers, and I’ve been bleeding the shit out of this truck for the last 3 days with multiple methods and no luck.

When the truck is off, everything bleeds fine, no air bubbles whatsoever. The pedal is stiff as a board during the process. Finish up all 4 wheels in the proper sequence, turn the truck on and the pedal essentially goes to the floor.

Just gave it another shot this morning and I bled the master cylinder beforehand just to make sure it wasn’t holding air. Same thing, bled well, no air in the lines, pedal stiff as can be. Turn the truck on and it turns in a mushy sponge.

I wasn’t having this issue before I replaced the calipers. Any ideas or suggestions are appreciated.

Edit: just to add, not leaking fluid anywhere. Is there a way to test the master cylinder to verify? Air in my ABS module?

 

You need a scan tool to bleed the abs.
Or find a gravel/dirt road and press the brake pedal hard enough to make the ABS come on.

 

Odd that you'd need to bleed the ABS module just because of a caliper swap, unless you let the system drain down to empty at some point.... regardless, that's what it sounds like. If you don't have a scan tool with that function, or access to one, than a gravel road, or neighbour's wet lawn are good alternatives. You will probably need to cycle it 2-3 times, and then re-bleed all four corners. Should be good after that.

 

Gotcha. When I started the brake fluid flush prior to installing the new calipers, I used a turkey baster and sucked out virtually all of the old fluid in the reservoir. Refilled it prior to cracking open any lines for the flush. Unlikely I got air in then.

My FIL came down for the weekend and brought his vacuum bleeder. We tried that yesterday. He was watching the fluid level in the reservoir for me while I was under the truck. He didn’t realize my reservoir has a front and rear section, so while we were doing the rears wheels, he was watching the front reservoir, so we bled the rear reservoir dry. That’s likely what did it.


Bled it again today and it feels a lot better but pedal still sinks when truck is turned on. I’ve got a dirt road nearby I’m gonna try out. I’m guessing the ABS dash light coming on will be my indicator for successfully getting it to cycle?
Thanks!

 

and the pedal with vibrate when your ABS kicks in..

 

Ummm… dual circuit master cylinders have been standard since about 1966 - was your father's last repair job for a family named 'Flintstone'?

You'll know when the ABS kicks on!

 

Haha, idk man, I think he just wasn’t paying attention. I’ll report back when I have a chance to hit the dirt road and bleed the system again.

 

The scan tool is only for trucks with traction/skid control.

 

This problem repeats something like once or twice a month. We should have a permanent on top stickie, BRAKES, READ THIS FIRST. Then explaining the problem, how to prevent, how to fix.

 

Had the same spongy pedal thing after my frame replacement in '16, finally went and bought all new brake parts
rotors, pads, calipers, rubber hoses.
Took it to my buddy who's a mechanic to do the work and he returned it in perfect order with a hard pedal, said all he did was gravity bleed the brakes cause he was alone and that's what worked.