How bad would it be if dust particles got in the Power Booster? Does brake fluid flow through it at all, or is it just a vacuum machine?

I am cleaning up the old one on my 71 cutlass supreme, and there is grease and tiny rust particles everywhere. I am trying my best to keep stuff out, so it shouldn't be more than a few stray particles or so. I just don't want to get it all back together and have a clog somewhere.

I will post pics, but I don't know how much detail I can get in a picture. Any help would be awesome. Thanks all!

 

The booster is just a hollow cannister, where incomming vacuum pulls on a diaphram.
Dust should not hurt it, but I would plug the vacuum hose connector going to it when doing sanding or or other work. The brake fluid only goes into the master cyl.

 

Thanks Rob! I was hoping that was the case. I will replace it with a new one eventually, but for now I just want her running, so I am going to sand & paint the booster, strictly for cleanliness. I didn't want the new master to look like a diamond on an ugly hand.

She's been sitting for soooo long. Once I am comfortable with regular operation, I will start to worry about the finer details.

Oh, speaking of the master, any tips on painting the cast iron? prep? With cast being a rough surface, I didn't know the degree of sanding required.

Thanks again!

 

Best way to refinish these things are to use the paints and coatings that Eastwood.com has. They have a gold cadmium spray for the booster and also an iron grey paint that is brake fluid resistant - a must for masters.
The master should be covered, ports plugged, and wirebrushed and cleaned well with brake parts cleaner. Final cleaning can be soap and water, but dry fast to avoid flash rusting.
On the booster, tape over the center openings to kepp sanding dust out.
Check out eastood's stuff - if done right, they will look new for a long time!