What's a simple way of cleaning the brake fluid reservoir.
 

I'm replacing my master cylinder and I noticed some nasty dark sediment on the bottom of the brake fluid reservoir.

Can I simply fill it up with brake parts cleaner, shake, remove, fill with dot 4, repeat shaking, and remove to completely clean the thing?

The thing has a funky way of filling up and I want to make sure it's clean before I put it back on.

I would remove it from the MC before putting anything in it other than brake fluid. Mine looks pretty bad too but the fluid is nice and clean.

Yeah that's exactly what I did.

I went ahead and did it anyway. Looks like it worked and I have it air drying in what little sunlight I have left. Looks so far to be pretty clean and the purge of dot 4 should have picked up any of the brake parts cleaner floating around in it.

Looks like my reman MC is actually a new unit. It's a identical to the unit on fastlane and there's a "new unit" stamp directly located on top of the box.

Use brake cleaner and compressed air.
 

I typically use standard issue brake cleaner and dry it out with compressed air. Total process time is less than 5 minutes.

This is a great precaution to take when swapping a reservoir onto a new MC.
be sure to 'bench bleed' it to remove any trapped air. This is often more difficult once on the vehicle.

Funky?

Yeah it took me awhile to figure out how the front of the tank fills up. I finally figured it out after watching how it fills itself up.

Already did the bench bleeding process. Pretty easy and filled up quickly.

Sounds good. You are in business.

Be sure to have a piece of clear plastic hose on hand to put over the bleeder nipple.
Put the other end into a clear plastic bottle. This aids in the bleeding process and controls the potential mess.

I would have suggested rubbing alcohol. That is what is recommended to clean my power bleeder after use. It is cheap and dries quickly.

You have probably figured out that there is a front and rear chamber in the reservoir. You have to be careful when bleeding that you watch the level of the rear chamber and not just the front, as you can empty it and start to draw in air.

Richard

Finished the job last night. Very surprised at how easy it was to bleed and refresh the brake system. It's nice to have really firm brakes again.

The fluid I pulled out was a watery black color. I guess I will be doing brake flushes as a yearly job. That fluid was really nasty for being only a year old.