bmore430

Bent Guide Pins on Rear Calipers? New Hardware Recommendation?
Changed my rear pads and rotors on my 2005 last weekend.

New pads and rotors went on. I noticed when I pulled the pins on each side the pins were bent. What causes this? The pads were just about down to the wear sensor when I replaced them.
I greased and re-installed the pins because I had to get the car back on the road but would like to order new hardware for both calipers with the pins, cotter pin and retaining clip.

Brakes have good bite and no noise or vibration. I do notice a slight grabbiness from the rears on hard stops. Almost feels like the ABS kicking in but I'm not sure if the bent pins are causing it. I never paid too much attention before on hard braking before I changed the brakes so not sure how it acted.

Beck Arnley and Centric make hardware kits. Anyone run into this?

rkw77080

The brake pads are slid inside the brake caliper loosely in 2 cutouts (or slots) on either side of the rotor. The caliper pistons push on the pads to squeeze on the rotor to stop the car. There is a slight gap between the caliper and the rotor. Lexus specifies a minimum pad thickness to prevent the pad to slip out of the caliper (into the gap). If you wear your pad down to less than 1mm, you will risk having the pads pushed too out of the cutout (or slot). When this happens, the pin is the only thing that is holding them in place and keep them from being pulled into the gap between the rotor and the caliper.

bmore430

The rear pads were probably 1mm or less as there was basically nothing left. This would have exerted more force on the pins causing them to bend then?

Tom57

You could carefully bend / hammer the caliper pins to straighten them.

With only 1 mm on the pads, the wear sensor wire should've been broken.

rkw77080

That's my guess. Normally the brake pad pin does not experience much forces. When brake is applied, the pads are thrust against the caliper in the direction of the rotor's rotation. If the pad is push beyond the edge of the caliper, it slips into the gap between the rotor and the caliper, which pulls on the brake pad pin and bends it.



So if my guess is correct, then there is a likelihood that your rotor is also too thin, which combined with the thin pads to create a larger gap. Please inspect to be safe...

bmore430

Thank you for your input.

I believe the rotors and pads were original and had 88k miles on them so Im sure the rotor was thin and not much left on the pads at all back there.

I replaced with brand new cryo treated rotors and akebono pads.

I just ordered the rear hardware kit from Beck Arnley and will install and report back to see if the pulsation goes away on semi-hard braking.

Rotor faces are glass smooth, no noise or vibration so Im hoping this solves it.

tradosauru

Make sure you use brake caliper grease on the pins before installing.