Brake "upgrade" leads to a soft pedal

Hey everyone. Ive browsed these forums for a while, but never signed up. I recently purchased a 2011 5.7L 4wd. After a couple months of driving around, I decided to upgrade the brakes with some power stop rotors, pads, calipers, new lower hoses (sunsong & ACDelco) & steel lines (toyota)

I had some help bleeding the system. We must have bleed them for 4 hours. The pedal got significantly better as we kept on going, but it never got back to "normal". The braking wasn't spectacular in the first place... the calipers were originals, and starting to seize up. The pedal was still relatively stiff.

We have wracked our brains for possible causes and have only come up with:
1) the ABS system still has air
2) bad brake booster
3) bad master cylinder (not likely?)

Are there any tricks to bleeding the brakes further? Is the softer pedal common after a brake job like this?

Also, probably unrelated, but the parking brake was dragging a bit after we reassembled everything. I noticed whoever replaced the rotors in the past forgot to replace the rubber plug. The parking brake hardware was a little rusted... probably caused the hardware to seize, but it seems to be moving when I take the rotor off.

Edit: accidentally hit send too early

 

How did you bleed them? You don’t bleed brakes on vehicles with modern electronic abs modules like you did on a vehicle from 30 years ago. If you “pumped the brakes” with the truck running, to bleed them, you surely got air in the abs module that can’t be remedied without a tech stream to cycle the abs system. Vacuum bleeders are the way to go to avoid this issue.

 

Exactly how you said -- by "pumping the brakes" lol. Which makes sense. The pedal feels great until the truck is started.

I read somewhere that you can activate the ABS by braking on a slick surface, or I suppose a gravel road. This may help force the air out. Anyone tried this? Seems dangerous but I've done dumber things.

 

Yep, you have to actuate the abs system while bleeding to push the air out of the module. The problem is you can’t do that while driving as you can’t have a bleeder open or you’ll have zero brake pressure to even activate the abs….or albeit you will have no brakes at all. The tech steam gives you the ability to cycle the electronic module while the truck is parked. May be easier to just bring it to a local dealership as they will have the equipment to do it.

 

Good call on the dealership. But as a man on a budget, thats why I was doing the brakes at home anyways lol. Maybe that will be a cheaper fix, though?

On another note, why do you see so many people still bleeding brakes the old fashioned way? Are they all getting air in their ABS module? Or did mine get so much air because I had open lines for so long?

 

Do you see them bleeding them the old fashion way? I don’t know anybody who’s pumping the brakes in their driveway to exchange fluid haha. Vacuum bleeders have been around a while and are the way to go on any vehicle made in the past 20 years with electronic abs. You leave behind a little bit of old fluid in the module by using a vacuum bleeder, but you can exchange 99% of the old fluid out without the risk of getting air into the abs.

 

Oh yeah haha. I definitely see people still pumping their brakes. The only thing I can think of is that they kept a closed system somehow. Ive seen a trick where you hook up a hose to a jug w/ fluid already in it. One end is obviously plugged onto the bleeder screw. The other in the jug, but submerged so it doesn't suck air.

Anyways. Thanks for the replies. I guess Ill invest in a vacuum bleeder now!