Very soft brake issue

i have a 12 trd. I replaced the wheel bearings, now my brakes are acting up. 50% of the time the brake pedal travels 2” or better before the brakes engage, like they are soft or nonexistant. If I hit them a second time they are normal. Other times it’s right there as it was before the bearings.

When I did the wheel bearings I never busted into the brake system. I’ve already checked the fittings all tight, adjusted the rear drums to just a drag, bled the brakes, activated the hell out of the abs. Rechecked the rotars. Everything seems good, no dash lights. I’ve searched but most of the posts are related to problems after doing brake work. Nothing addressing these problems without even messing with the brakes. Help me please, I’m at my wits end.

 

Welcome to TW.. I got nothing..

 

That kind sounds like your either master cylinder or booster gone bad.

 

The system is a lot more complicated than the gen 1’s is it still easy to change or a blast.

 

2 inches of travel is not a problem but soft or especially non-existent is a serious issue. Still on the original pads and rotors? ABS certainly complicates the brake system but other than that it still uses the same tried and true principles as they always have, ie hydraulics assisted by vacuum. It sounds to me like you might want to take the truck to a shop experienced in troubleshooting brake systems. At least get a diagnosis then make a decision whether you want to tackle the job yourself.

 

Are you getting good pressure from all 4 corners when bleeding? When you bled the brakes did you have the key on and engine off? Any leaks in lines? Maybe you bent a line during install and now it may be sucking air?

 

I would agree that it’s not a big issue, however the brakes are soft one push (2”) takeup, then 5 minutes later is solid with little takeup like nothing is wrong. At this point it’s a gamble weather it will stop. It’s just mind boggling because I didn’t touch the brakes except to remove the hose brackets and the calipers. Hard lines are in good condition as are the soft ones. I bled the brakes despite knowing that I didn’t break any seals to the system. Ill have to take it to a shop, it’s beyond my comprehension. I was hoping that there was maybe some relearn process or something since I removed the wheel sensors. When reinstalling them I put a bit of grease on them, is that bad?

 

The rear breaks just need adjusted.

 

Does yours have the electro-boost unit?

 

I would assume so, there i don’t see a booster that looks like a big pancake and there isn’t any vacuum lines to the brakes.

 

Engine off, key off, good pressure. No air

 

One of the first things I did

 

The brakes should be bled with the key on

 

Any abs/trac lights on?
Edit..sorry, just re-read first post, no dash lights..

How long has this been going on? Are you needing to add brake fluid as time goes on? Did you check to see if the wheel cyls were leaking when you adjusted the rear brakes?

 

I noticed the problem immediately after I finished with the wheel bearing install. Absolutely no signs of fluid leaking or anything.

I’m having a hard time believing that it is related to air in the lines because I never once compromised the brake fluid system.

When I did the front wheel bearings I removed the brake line clamp, then two 17mm bolts and slid the brakes off the rotar and hung them from wire with no tension on the lines. But I’ve been proven wrong before, I followed the same procedure 7-8 months ago when I changed all the brakes which resulted in no issues.

I did put grease on the wheel speed sensor after I cleaned it off. But if The sensors were an issue wouldn’t I get a light?

 

Can you feel the ABS coming on or any motor/humming noises?

 

Just this am I sped down the driveway and slammed on the brakes to activate the abs. No change - and the abs works

 

Sounds normal to be honest. I posted a few weeks ago that my brakes all of a sudden became firm and would brake with a lighter push on the pedal ( like every other vehicle I’ve ever owned) after 8 years of being mushy. Then a few days ago, it went back to being mushy. Oh well. Everything if original with plenty of pad left, no leaks in the brake system, he’ll the fluid in the master cylinder is still clear and full. No warning lights either.

 

I’ve owned the truck for 4 years, and it just happened, I’m not saying it’s not normal for your vehicle but for mine it’s very abnormal. It’s a noticble difference in the brake performance that is unpredictable.

 

If it's obviously different than it was before your work, then I'd say something definitely changed.
Did you have to push the pistons back in the caliper when you put it back on? Maybe one is stuck back??