someotherguy

2006 Silverado SS - 133K miles. Wife calls me a few days ago says it's acting funny, I meet up w/her and it seems like the brakes are locked up, pedal is firmer than usual, too. We're not far from the house so we leave the truck and I'm calling a buddy w/a wrecker.

Couple hours later we go to tow it and it rolls freely. I figure ehhh, must be the flex hoses, right? It's possible with the age/miles and it seems to be fairly typical behavior for that issue. Ordered the hoses and they arrived last night, installed them today. All 3 hoses (rwd/rear drum brake truck), and bled the system. Was careful while doing the replacement so didn't lose much fluid anyway. Test drive it around the neighborhood, seems fine.

Took the truck on a little bit longer drive around the area and I can tell they're starting to drag down. Get it home and do a little back-and-forth in the street until they get worse. Pull into the driveway and jack it up, both front wheels are locked solid, can't turn them by hand. Jack up the rear and put in neutral, both rear wheels spin OK.

Ideas?

Thanks!
Richard

strutaeng

When the wheels were locked solid at first it was also in neutral? 🤔

Sounds like maybe something mechanical on the drums, but I have honestly never taken a drum brake system apart.

pknowles

iTrader: (1)

While my truck has never done this, my mothers car did this exact same thing and it was the ABS unit. After doing some diagnostics, if it is the ABS unit, there are places that rebuild them.

terravast4

iTrader: (25)

he states the front tires are locked up

someotherguy

Correct. Fronts are locking, rears seem fine.

Richard

strutaeng

Oh sorry, I missed that it was the fronts. 🤦

Then it should be seized caliper slide bolts/hardware? I'm assuming the front brakes had been replaced at some point? I recall I did the first set on my 99 Silverado a little over 100k, maybe 120k (?), although my mechanic later told me they still had plenty of life after he'd replaced them. Depends if you do a lot of city driving and brake usage patterns.

adriver

iTrader: (1)

Mind if I ask why it can't be the ABS? It it's both fronts doing this, and not the rears, isn't the ABS the first possible option, maybe the proportioning valve, (again, I don't really know).

strutaeng

Pull the ABS fuse to rule EBCM.

someotherguy

I'll give it a try. probably a little later today.

Richard

someotherguy

Something else I considered is the fluid looks nasty, probably needs to be flushed. Before I do that though I want to measure the water content so I know just how bad it was before I get rid of it. With that in mind, I ordered a brake fluid tester that should hopefully arrive this evening. I added a bit of fluid before changing the hoses so that the reservoir wouldn't go dry when I bled the system, but it didn't take much as I lost very little fluid doing the job, and used a one-man bleeder cup to bleed it afterwards. So, very little fresh fluid in there at the moment.

Richard