Occasional Shaking While Braking? Second pair of new rotors.

Truck had new calipers, brake pads, rotors, drum brake, lines, components, cylinder and fluid installed by me (using mostly rockauto parts). After about 50 miles it started shaking during braking really bad. Exactly like warped rotors would. Brake light would also occasionally come on.

Took it to a trusted shop I've used for decades to ensure I didn't mess anything up during install.

They inspected the rotors and drums. Said they looked used but everything else looked good. They replaced them with NAPA parts which fixed the issue for about 1k miles. Now it's doing it again, but not nearly as bad. Seems to mainly happen if I don't apply full pressure and shaking is more noticeable if I'm going downhill.

I also had new ball joints (upper and lower w/OEM), alignment, and tie rods installed during the first brake change. The steering rack is less than 20k miles old as well.

Really not sure what else to check for here, but I'm running out of ideas. The original rock auto rotors/drum were sent back, as they did in fact look used & resurfaced and painted. A few chips within would showcase that. I'm surprised as I've used RockAuto for years and never had an issue. They were also the higher end options on there.

 

Are your rear brakes activating at all? If something is wrong there and you only have front brakes it could wear them out faster. Just a thought.

 

They should be. When on a lift, we tested the brakes and could see the rear shoes open and close.

 

Have you re-torqued your wheels with a torque wrench?
That should be done 50-100 miles after any time a wheel is removed and replaced.

 

I have not. They are upgraded 4Runner wheels, the silver/black combo from a 2018. Not the TRD wheels. They are the same pattern but 1 inch larger (17) than stock. Might have something to do with it? I'll torque them down and see if that helps.

 

Is your truck stock or so you have a lift?

Is the rear brake proportioning valve (BPV) fuctioning correctly? It automatically adjusts rear brake pressure to account for loaded bed weight. Basically, bed weighs down, valve allows more brake pressure to rear drums which releives front discs from doing extra work.

 

I would consider looking at the lower control arm bushings.
They can be replaced inside the oem arms (better solution to aftermarket arms, but more labor intensive)
If the frame side lower control bushings are worn out, this can cause a shuttering motion when braking. You can feel this in the steering wheel a bit as well, depending on how severe.

On a bmw, but this gets the point across:
https://youtu.be/83Pw3V8pMeI

 

Had a bad shimi in the front on a long trip. Took a while for my brain to remember all that stuff I used to know, but I ended up tightening the lugs at a rest stop and it reduced it to tolerable. Too late to save the rotors but now I re-torque whenever I get it back from a shop that had to remove the wheels and then again about 100 miles later.

 

Truck is completely stock, aside from upgraded wheels (17" Runner take-offs). To be completely honest, I'm unsure about the BPV. Never thought to check it, but it could likely be malfunctioning as it's a bit crusty underneath.

 

Could be over adjusted rear brakes too. I'd try backing the star nut off a turn or two and see if it improves.

 

If the rotors have a buildup of rust behind them it could cause them to be eccentric.

 

I've never had anything but trouble with aftermarket Road Rage rotors and pads...
Also need to have the Hubs checked..seen it a few times
https://youtu.be/mW3Uqqi61BM?feature=shared

 

Sounds like alot has been replaced. Wouldn't hurt to check those bolts, too, while you have the wrench out.