Brakes making contact on rotor. This Normal? - PeachParts Mercedes-Benz Forum

markho · #1 10-13-2009, 08:43 PM

I replaced my tie rods (what a pain) and noticed that the brakes make some contact with the rotor. Is this normal?

bobodaclown · #2 10-13-2009, 08:45 PM

brake pad yes. calipers no. Could you be more specific. Picture?

markho · #3 10-13-2009, 09:05 PM

too dark for pics. The pads just lightly sit on the rotors.

pawoSD · #4 10-13-2009, 09:11 PM

Quote:

Originally Posted by markho

too dark for pics. The pads just lightly sit on the rotors.

That is how brakes work.

And I sure hope you plan on getting the car an alignment now that you changed the tie rods....

MBeige · #5 10-13-2009, 09:14 PM

The pads are slightly touching the rotors to minimize the time it takes to step on the brake pedal and the pads to contact the rotor (to stop the car). If you turn the wheel with the wheel off the ground, it should spin freely without resistance. If not, then your calipers are stuck.

markho · #6 10-13-2009, 09:53 PM

Quote:

Originally Posted by pawoSD

That is how brakes work.

And I sure hope you plan on getting the car an alignment now that you changed the tie rods....

LMAO!! Dad, is that you? Yes alignment is getting done tomorrow. Thanks. I am new at this.

pawoSD · #7 10-13-2009, 10:13 PM

Quote:

Originally Posted by markho

LMAO!! Dad, is that you? Yes alignment is getting done tomorrow. Thanks. I am new at this.

Just making sure.

ah-kay · #8 10-13-2009, 10:20 PM

If you suspect the brake is binding this is what I normally do:

1) Find a stretch of straight road and come to a rolling stop WITHOUT touching the brake, may be from 30mph.
2) Touch the rotors with your hand and feel the temperature. They should not be hot.

The pads should be very close to the rotors but it should not bind and generate any heat. The rotor is not 100 true and it will push the calipers in when it rotates.

Good luck.

babymog · #9 10-14-2009, 09:55 AM

Ah, ... I would not touch the rotor. Spit on it, check with a non-contact thermometer, compare the temperature of the four wheels, but the rotor if hot can be several hundred degrees F or more, ... instant burns. If it's not dragging, you might be fine touching it.

fruitcakesa · #10 10-14-2009, 10:11 AM

Quote:

Originally Posted by babymog

Ah, ... I would not touch the rotor. Spit on it, check with a non-contact thermometer, compare the temperature of the four wheels, but the rotor if hot can be several hundred degrees F or more, ... instant burns. If it's not dragging, you might be fine touching it.

ouch X2

ah-kay · #11 10-14-2009, 12:15 PM

Good point but if the pads are binding/dragging to cause the rotor to reach serveral hundred degrees then one would have felt it already. There is NO need to do the test.

May be squirting some water on it. That would tell whether the rotor is good to touch. Obviously a non-contact thermometer is the best, if one has one. I need to count my lucky stars as all my digits are here.

swheele2 · #12 10-14-2009, 01:38 PM

How about just touching the wheel? In my experience, with dragging brakes the wheel was hot enough to notice but not hot enough to severe burns.

pawoSD · #13 10-14-2009, 02:18 PM

I just hover my hand near the wheel at the top, if heat is rising out, then its HOT.

lutzTD · #14 10-14-2009, 03:04 PM

usually a dragging rotor can be smelled before you even get close, but they sell IR thermometers now for $29. I always check rotor temps after a brake job, saved me once on the excursion when I cheaped out tried to free it up instead of replacing the driverside rear caliper

E150GT · #15 10-14-2009, 03:27 PM

I drove my dads truck about 1 mile and had a flat replaced. While the wheels were off I decided to touch the rotor for some reason. Bad mistake!