Rear Calipers Not Compressing

[045spdIS300]

Just noticed that the rear rotors do not have a wide band of shiny metal where the brake pads make contact. On the passenger side in particular there is just a thin strip where it looks like the brake pad is taking off the rust. The rest of caliper is rusted and maybe glazed.

I have not pulled the rotors off yet to look at the other side. I did note that the inside brake pad is wearing at least twice as fast as the outside. Which leads me to believe the inside side of the rotor is well worn and grabbing when I hit the brakes. I have 75000 on the car and I have already changed out the rear pads once due to uneven wear. Maybe a bad caliper?

I did a quick bleed at the caliper and the fluid did not appear to have any air in it. There is enough fluid in the brake fluid reservoir.

About 10000 miles ago I changed out the brake fluid myself. Maybe that has something to do with it?

Any ideas would be appreciated before I get ripped off at my favorite brake place.

Thanks

[smooth1]

Sounds like the booster/ cylinder or the valve is stuck. You may need a new one.

[045spdIS300]

Sounds like the booster/ cylinder or the valve is stuck. You may need a new one.

Thanks Smooth1.

Anyway to test which at home, or do I need shop equipment? So each caliper has a valve on it? That would make sense.

It does not look like either rear caliper is grabbing great.

Thanks again.

[IanH]

Sounds like the booster/ cylinder or the valve is stuck. You may need a new one.

Thanks Smooth1.

Anyway to test which at home, or do I need shop equipment? So each caliper has a valve on it? That would make sense.

It does not look like either rear caliper is grabbing great.

Thanks again.

I don't know how far you got with this. Sounds like a seized caliper.

If you remove it you can overhaul it or just get a re-built.

[045spdIS300]

I don't know how far you got with this. Sounds like a seized caliper.

If you remove it you can overhaul it or just get a re-built.

did not get very far. the pads are pretty worn on both sides and the rotors are shot. actually I ordered new rotors and pads and will put them on tomorrow and rebleed the system with blue brake fluid to make sure I get a good flush. the problem is on both sides so I suspect it is something to do the booster or master cylinder or fluid.

if the problem persists I will go to the dealer. she is due for her 90K. i figure a good overhaul at the dealer every 5-6 years is a good thing.

will let you know how it turns out.

[045spdIS300]

the inside pistons on both rear calipers were "frozen". They would compress, but not retract. the car only has 80K on it, but it has gone through 7 salty new england winters, so there you go.

thanks for the posts, I hope this helps someone else.

[Lexus300Stock]

I rebuild my caliper pistons... I had a stuck piston in the front calipers.. All is gone and my 60mph. shaking and vibrations is GONE.. Its so quiet and everything..

I advised you to rebuild your pistons in your calipers.. Its very easy to do if you have time on your hands.. I did all 4 calipers in 3 hrs.