bryceis250

wow really? mine are autozone rebuilt junk. feel stupid handing over my OEM cores for their china cores, but its done. however, the problem was there before the calipers , which is why i changed the calipers to begin with . would bad hubs slow up the wheel and cause that kind of heat?

2013FSport

iTrader: (2)

Has the master cylinder (MC) ever been off?
If there is NO freeplay between the brake booster and the MC, the MC can hold the brakes partially applied and cause this problem.

To check; unbolt MC from booster. Insert clay or putty into the cup and seat the MC fully onto the booster. Now carefully remove the MC and inspect the clay. If it is mashed clear through to the bottom of the piston cup you have no gap and the brakes are being partially applied.

The putty should not be completely displaced.
If there is no gap, **usually** (never done this on mine) the pushrod can be shortened with an adjusting nut at the end. But knowing lexus they may make you buy a new one that is shorter. The plunger and seal should pull out of thr booster for inspection. I suppose if none adjustable one could grind the end off to create clearance. It only needs a 1/32".... some!

bryceis250

man this is space talk lol. i have no idea, but this is the first real answer ive gotten. this wasnt happening until i did the brakes and new rotors. i then replaced the calipers thinking that was the problem. its at a garage right now and if he doesn't find anything i will be passing this along. thanks so very much. ive spent a couple hours reading on this and theres no answers, just a bunch of armchair mechanics saying the same things and speculating on everything under the sun. thanks!

the heat is on the rotor the hat is cool. the M.C.has never been off

bryceis250

the heat is coming from the rotors, the hat is cool to the touch

MikeFig82

iTrader: (13)

Just out of curiosity. Are you sure they didn't give you rotors for the 350? They should be vented like the front rotors. The 250 are solid.

Another thing if it's aftermarket brake pads. Make sure the ears are not oversized, and hitting the caliper. They need to float freely on the pins.

bryceis250

they are solid. off rock auto but htey were over 120 a piece , came as a set pads belonged to these rotors. this is sounding like its over my head and time for a professional mechanic, which is what ive done its at the garage. thanks for your input much appreciated. i have another question for you, any particular aftermarket rear shocks youd use outside of ones right from toyota?

MikeFig82

iTrader: (13)

Well once my shocks go out I normally go with coilovers. It's more cost effective unless you want to spend all the time compressing springs, and what not. Then DIY then it's probably way cheaper. I honestly don't have any experience with aftermarket shocks. I've had the Megan Racing coilovers on my old GS400. They were good 5 years later up until I sold it. This time around I'll probably try out the BC coilovers. As I'm due my rear shocks are blown anyway.

2013FSport

iTrader: (2)

This is solvable at home.
Pull the pads out and completely compress the piston. I opened the bleeder and my rear pistons pushed completely in by hand.
Install caliper and pad hanger.
Does it slide back and forth by hand? If no, we start here.
If yes, install the pads. Install the caliper. Can you push the caliper from side to side and make a small air gap between the pads and rotor? Does the rotor turn by hand? If yes, it seems the mechanical aspect is OK.
Press the brake pedal several times. Can you turn the rotor by hand? If no, this is a hydraulic issue. Likely related to the MC as mentioned above.

Air trapped in the lines can induce a light drag on the pads. It should not make them 300 degrees.

So what can you tell us about this vehicle? If since you have owned it, it had the rear pads shot, it is a good possibility the MC has been off and the plunger in the booster needs adjusted.

banec13