Grease on Brake Pads

[CWizard]

Let's suppose that a blob of grease found its way onto a rotor and then got deposited at the top of the caliper as the rotor turned, and then said blob got hot and oozed down onto the pad. So there's grease on the rotor and also on the pad. What effect would this have on braking? Reduce braking efficiency? Cause grabbing/lock-up on that side?
Has this ever happened to you, or am I just uniquely lucky?
Thanks!

[Rich A]

Reduce braking efficiency.

[jams]

If they were meant to be greased they would have a grease fitting. I would say reduced efficiency.

I have seen years ago rear drum breaks lock up very easilly when the wheel cylinder leaked break fluid on the shoes.

[Tim Brewer]

Just spray the rotor and pads down with some brake cleaner.

[HI Cobra]

Like others have said, any contaminates like oil or grease will decrease
efficiency. Same as getting oil on a clutch disc - watch it slip after that
happens. Been there and done that when the front seal on my tranny leaked
fluid which got on the disc so I had to replace it. You might be able to clean
small amounts off but I'm thinking the best bet would be replacement of pads.

[RICK LAKE]

CWizard If you want to try the quick way, get a couple of cans of GOOD brake clean and a wire blush and clean the parts with this. If you have a small sander or belt sander with a #200 grit rating, Hit the surfaces of the pads and both sides of the rotor. You want to remove the glazing on both parts. Doing this is cheaper than to get new pads and have the rotor resurfaced or replaced. The problem is the grease gets hot and melts into the pores of the pads and rotor. Cutting .003-.005 off the rotor will give you new virgin surfaces. Any idea where the grease came from?? CV boot if you have a IRS rearend? Rick L.

[Double Venom]

C-
The rotor with grease will not grab hard causing the other brake to grab. Easy way to fix is remove the offending brake pad(s) celean with brake cleaner as stated then re-rough up the pad by rubbing it back and forth on asphalt or concrete just to rough it up a little. A racers trick when he has to change pads a the track or take some 80 grit paper and rough up the pad. OR just replace the pads in a pair and clean the rotor. Nothing trhat hasn't been done hundreds of times before.
DV
RICK was typing quicker than I, his suggestions are right on too!

[CWizard]

Originally Posted by RICK LAKE

Any idea where the grease came from?? CV boot if you have a IRS rearend? Rick L.

Yeah, a very good idea. The upper ball joint was hit too hard with the grease gun and forced grease out the seal. Then the grease got a ride over to the rotor on the tech's hand. Very sloppy work.
Another reason not to get too zealous with the grease gun.

Thanks for the responses.

[RICK LAKE]

CWizard He have had similar problems at the dealership I workeed at with the lube techs and air powered grease guns shooting all over. They hit the rotors calipers, tires, wheels, and body parts. Go back to the service manager and tell him the problem you had after you left the shop. Tell them the brakes where working fine until JO-JO lubed the front end. If there is grease all over don't remove it and go back to the shop. Tell them you want this cleaned up. The rotors will have a funny glaze on the surfaces same with the pads. Take pictures of the parts and poor workmanship. If they decline to repair the car to your satifaction, meaning grease removed from everything including wheels and tires, Tell them you will see them in court. Take the car to a certified shop and have them fix the car. Save the bill and goto court. You will win everytime. Pictures are worth $500.00 dollars everytime. Try the asy way first. Shop foreman, Servicemanager, Senior manager of the store, Corperate after this. Telling friends about there poor workmanship goes along way too Rick L.

[CWizard]

Hey Rick, thanks for the suggestions. In this case, I have already destroyed too much evidence. Wasn't thinking about accountability, just trying to understand what happened and fix it. But next time....
Thanks again,
Jerry

[Excaliber]

Strange how grease affects DRUM brakes, it does make them tend to 'lock up' if it's a relatively small amount. I GUESS if it was a huge amount it might make them 'slip'.

Interesting question as it concerns disc brakes. I wouldn't assume the rotor/pad would 'slip', it might make it tend to 'grab'. A small amount could most likely be handled with 'Brake Clean', but to much and theres not much you can do to get rid of it. Clean and see if it 'pulls' to one side or the other, under light or hard braking, like I said, interesting question.

[COBRANIP]

My buddy in high school had a Vespa (scooter). His brakes squealed so he thought some grease on 'em ought to take care of it. Good news! No more annoying squeal! Bad news! Couldn't stop his scooter at the end of his street! Tore up a neighbors yard and his scooter when he bailed off. Oh, to be young (but not as stupid) again!