cleaning petrified brake fluid

[Guest]

On my calipers I was able to scrape most of it out, but I am cleaning up 2 master cylinders and some of that stuff is on there like dried glue. Especially in the groove where the reservoir o-ring sits.

Any tricks for getting that stuff off?

[GelandeStrasse]

WD40 often works for cleaning. It's a good start point because it won't wreck anything(unlike brake cleaner etc) I don't know if it'll work in this case though but worth a try.

[steve murdoch]

Dremel tool with the brass wire brush attachment worked for me.
If you don't over-do it the brass is soft enough that it won't damage the bore.
Second choice is a set of dental picks available for cheap at Harbour Freight.

[tkent02]

Carb Dip.

Just rinse the stuff out when you're done.

[BluePlateSpecial]

Cool, I will give those a shot.

[bwringer]

Carb dip and heavy use of brake cleaner will remove the paint, so be aware of that. My rear caliper looks kinda cool in silver, so I left it that way...

I've always used wooden implements (popsicle sticks, broken-off cotton swaps, old pencils, etc.) to attack these deposits, then cleaned everything up with the fine Scotchbrite pads.

You can also get plastic cleaning sticks that work very well -- they're normally used for cleaning firearms, so check your local sporting goods or gun shoppes.

You may need to go around the seal grooves once or twice with a dental pick to get the crud out of the corners, but other than that you should avoid metal tools.

[nastyjones]

If you have access to an Ultrasonic Cleaner, it will clean calipers & master cylinders to "like new" condition in minutes.

[BluePlateSpecial]

The paint is toast so I will be repainting anyway.

The stuff that is on there is very hard so I did uses a metal pick to scrape the bulk of it off but it is going to take some kind of solvent to break the rest down to a point where I can get it out safely. WD40 didn't seem to touch it. I have a partial can of carb cleaner I am going to try. I also have a dremel so I should be able to get these things clean one way or another.