Extreme vibration after brake job

[PeterTheBeater]

Hi,

I’ve for a 1997 FJ80. Did wheel bearing repack, front caliper rebuild, new rotors.

Running some heavy 35s, torqued the front bearings to 30ft/lb. New rotors torqued to hub at 57ish. New caliper bots are torqued at 90. Caliper rebuilt with plenty of lube and Toyota kit.

Rotors DBA T3. Pads DBA XP 100 series. Rear DBA T2 and DBA SD pads. (I’m certain the issue is not from the back).

The issue, getting some really rough front end shaking when braking from 60mph+.

Got three ideas:
1) the rotor didn’t sit completely flush to the hub one of the wheels.
2) when I put 100 series pads in, they didn’t fit (too thick), so I had to loosen the caliper and put them in. Maybe that pressure is affecting the rotor at high speed.
3) rotors warped out of the box.

When I did the break in procedure, no shaking or weird things when braking hard from 45mph. Noticed the issue day after.

Thoughts?

 

[DIRTBIKEUSA]

I have had brand new drums (on my tundra) that have had heavy vibration when braking. Took them off and had them turned and the vibration was gone. I would start there. Inspect your work when you go to remove them to eliminate other causes.

 

[Kernal]

Jack up the front end, push pull on the tires at 6-12, 3-9 O'clock to check for looseness, clunking
Also rotate the tires by hand to check for smooth/even rotation
Remove tires and check that the calipers aren't loose
Pull the brake pads out, inspect, ensure the pistons are pushed all the way back, then see if the pads will slip back in.
Compare the thickness of the DBA 100 Series pads to a set of Toyota 100 Series pads. If any differences/concerns, install the Toyota pads.

FWIW I'm running DBA rotors and Toyota 100 Series pads (which were a bit snug to install), no issues and the vehicle stops very well

 

[PeterTheBeater]

Jack up the front end, push pull on the tires at 6-12, 3-9 O'clock to check for looseness, clunking
Also rotate the tires by hand to check for smooth/even rotation
Remove tires and check that the calipers aren't loose
Pull the brake pads out, inspect, ensure the pistons are pushed all the way back, then see if the pads will slip back in.
Compare the thickness of the DBA 100 Series pads to a set of Toyota 100 Series pads. If any differences/concerns, install the Toyota pads.

FWIW I'm running DBA rotors and Toyota 100 Series pads, no issues and the vehicle stops very well

Yeah I’ve had 100 pads before and no issues. First time something like this happened to me. Unfortunately no OEM pads to compare to.

 

[Kernal]

Can you buy a set of Toyota 100 Series pads from a local dealer (or go with 80 Series pads?)?

 

[CharlieS]

If you had to loosen the caliper bots to get the pads in, maybe you had too much friction, overheated the pad/rotor and left pad deposits on the rotor.

 

[robnicko]

did you happen to install the 100 series pads with the original 80 series shims still in place? From what ive heard when using 100 series pads the shims are deleted due to their increased thickness which would cause the constant rubbing, heat build up = vibration

 

[PeterTheBeater]

No shims, the 100 pad came with its own shim backing.

The the rotor was hot, it wasn’t that hot, as the paint marks haven’t changed colors, so it didn’t get above 400 F

 

[Kernal]

If you used removable shims with the pads that might be an issue. I did not use shims with front Toyota 100 Series pads and DBA rotors but it was a snug fit even without shims, had to lightly tap the pads into place ie: they would not just slide in. No issues after that.
FWIW

 

[PeterTheBeater]

I guess the shims were the issue.

Torque on rotor to hub bolts was ok, the rotor seem to sit flush with the hub as well. Loosened the caliper, removed the shims on pads and torqued the caliper first, then put the pads in. The fit was loose, the pads almost fell thru.

Took on a quick drive and no issues at this point.

Thanks all