Caliper Rust

[Rich]

Good morning all,

I'm just wondering what your experiences are regarding rust accumulation on brake calipers. I recently had my rear brake calipers replaced on my 1997 Eldorado (124K miles) at a GM dealership with genuine GM parts. Within a week or so, I noticed light surface rust developing on the calipers in spots. The front calipers, which are original to the car and are now almost 14 years old have no visible rust on them. The fronts appear to be a dark gray to black burnished color. The new rear calipers are silver in color. I've searched online for "rusty calipers" and have come across many instances where drivers are reporting the same issue on their cars for many different makes of auto, including the bigger premium brands.

I understand that the calipers are steel castings which would normally be prone to rusting fairly quickly. But I would think they would be coated with clearcoat or some equivalent from the factory upon manufacture. After all, my fronts don't appear rusted, nor do most (not all) calipers I've been checking on the street. One online post I saw indicated that the calipers will first develop a light surface coat of rust, and then burnish to a blackish color over time, perhaps years. There are three other cars in my family, all with original calipers and fairly new varying in age from four years to three months. None of the calipers have surface rust. I'm not sure what to make of this, and whether I should contact Cadillac Customer Service to complain.

Just wondering what your experiences are. Thanks all.

[KHE]

The rust on the outside of the caliper will not affect its function. My guess as to why the rear calipers look so much worse is the spray of road debris - especially road salt if you live in an area where road salt is used.

[Rich]

I know the functioning isn't affected. But cosmetically it is unattractive as you can clearly see the calipers through the wheels. What I'm saying is that the fronts show no rust after fourteen years, yet the rears show rust after one week. Calipers on new cars sitting on dealer lots don't seem to be rusted. Why would my brand new expensive GM OEM calipers show rust after a week? And should I expect this light coating of rust to burnish to a blackish color over time, or will they soon turn a horrible orange (rust) color?

[CarlaValentine]

Have you tried contacting the place that you got them from? That's what I would do if you are really concerned about it. Perhaps something changed in the way they manufacture parts since 1997?

[Rich]

I had a bad experience with this dealer (a Buick/GMC dealer) and won't be dealing with them again in any capacity. My regular Cadilac dealer closed as a result of the economic collapse, so I was forced to use another which I had no experience with. Before installing these calipers, this Buick dealer installed VERY OLD and VERY USED calipers while charging me for new. I contacted Cadillac Customer Service who got involved directly, so I'm comfortable that the calipers that are on the car now are new GM OEM. The dealer photographed them upon installation (likely requested by Cadillac CS I expect) and they were clean and bright when I picked the car up. But as I said earlier, I'm quite surprised that they would show signs of surface rust within one week. I have absolutely no trust in this dealership, and wouldn't even use them for an oil change, so any contact I have will be with Cadillac Customer Service directly. But before contacting them, I was just wondering what others are seeing out there in the field.

[CarlaValentine]

It does seem a little odd. I looked at mine when I was outside a little bit ago, and they are blackened with brake dust but there isn't much rust to speak of. Mine are the originals to the car, which is a '94. The pistons in them have been greased any time work has been done on the brakes, which I am guessing is the reason they have never needed replacing.

If what you are seeing is surface rust, then it should be easy to clean off. Then you could wipe them down with transmission fluid or WD40 to help prevent further rusting. Don't spray anything on them, and be especially careful not to get it on the brake pads or rotors.

[Rich]

Maybe that's the answer then. Maybe what I'm seeing on my original front calipers is years of accumulation of brake dust. Perhaps that's why they've turned a dark grey to black color. I expect the same will happen with the rears, and the unsightly orange rust spots will be replaced with a coating of brake dust over time.

I think I'm good to go. Thanks!