Smoking Brakes

[ptomey]

Tuesday after driving our 68 280SL a short distance on the interstate at about 75 MPH, we got off the freeway, made a few turns on some city streets and arrived at our destination to find the right rear wheel smoking heavily.

I am very familiar with the smell of overheated brakes on race cars and modern street cars but this smell was foreign to me. I thought maybe I had a leak in the caliper and I was smelling brake fluid burning on hot brake parts but I pulled the wheel, pulled out the brake pads which had plenty of friction material on them (at least 7 or 8 mm) and there was no evidence of a leak (and no perceivable reduction in the reservoir).

I’ll bleed the brakes and add fresh fluid but what’s with the smoke? Could it be something else besides the brakes?

[gary ensor]

I would check to see if the caliper is sticking or if you have a defective flexible brake hose. Remove the right rear wheel, get in the car and pump the brake pedal several times hard, then see if you can turn the rotor. If you can't turn the rotor,open the bleeder valve to see if that releases the pressure holding the brake on. if it does your hose could be defective. Brake hoses deterioate on the inside and act like a check valve holding pressure on the caliper. If they look old or you don't know when they were last changed i would replace them all and flush the system with new fluid.

[Cees Klumper]

As Gary points out, most likely your brakes are seizing up which is most likely being caused by the brake hoses clogging up on the inside. This happened to me last year, albeit on one of the front brakes. Replacing all hoses is a cheap, quick and worthwhile procedure particularly if you don't know how old the hoses really are ...

[BHap]

parking brake hanging up ?

[ptomey]

Thanks for the replies, it's only the right rear so I doubt it's the e-brake. Releasing the presure from the bleeder does not seem free it up. Does that imply that it's something else? Bad caliper possibly?

[gary ensor]

Can you push the brake pads back away from the rotors, retracting the caliper pistons back into the calipers ? If you can't the caliper is sticking, if you can the parking brake shoes may have come apart inside causing the problem since i assume no one has adjusted them before you took your last drive in it.Or it's possible the right rear parking brake cable has corroded inside the cable sheath and is not releasing tension on the parking brake assy on the right side. You can get under the car and pull down on each cable in the area between where the sheath attaches to the floor pan with a clip and where the clevis end of the cable attahes to the equalizer assy. It should move in and out freely. Be sure the brake is in the release position.

[JimVillers]

Paul .... You might have lost a rear wheel bearing.  The leaking differential fluid on the hot brake is a different smell than "hot brakes".  

When it happen to me, I was also on the interstate and I felt like the Red Baron, trailing smoke and feeling "shot down".