Yes, It's sad the damage done by salts.

https://newsroom.aaa.com/2017/02/roa...e-rust-damage/

I had to go over every square inch of my truck frame and underbody removing corrosion from one winter's travel in road salts. It's amazing how fast it takes the toll on all things steel and iron. Lots of wire wheeling and painting and corrosion inhibitors. Glad I found out about Fluid Film. Did a great job on the frame, axles, calipers, brake lines and suspension elements. My underbody was well protected as it was entirely undercoated before the exposure to the salts. That said I completely scrubbed the underbody clean and re-did the undercoat. I'm very happy with the results. No more salty roads for my truck!

 

Yes I purchased a booster, master cylinder and a 25 foot roll of copper nickel tubing. I only can work outside so have been waiting for a dry day. I was able to get the master loose and the lines to disconnect. I then removed the power booster. I am sure it had never been replaced. It was a wrestling match all the way and had to hit it with a hammer to dislodge from the fire wall. I went from there to the proportioning valve.
Ha Ha Ha! I think the engineers had a challenge to see how many different size fittings and flare nuts they could put on one piece. I will try to document this with a picture soon. Just know I had to use an 11mm in place of 7/16 on many of the nuts because of corrosion and them not wanting to turn. They proportionining valve had a 7/16, 1/2, and a 5/8 flare nut fitting on it. That is for four fittings on this valve, there were 3 different nuts.
I bent the mounting bracket for the valve trying to get the fittings loose. I may have to remove the bracket from the frame in order to straighten it back enough to reconnect or may could bolt the valve back using only one screw. There were two 8mm x 1.25 bolts holding it on ( used a 10mm socket to get it loose).

 

I went to every close by auto parts and was unable to find the correct adaptors in order to use a standard thread, 3/16 inverted flair and adapt to fit the master cylinder or the propotioning valve. This is not well organized around here and had multiple people trying to help me find the correct lines with standard thread fittings. They were fortunately marked with a lable in most cases and had to keep telling them they had the wrong flair or a metric thread. I had the new and old master cylinder in order to prove it was the correct fitting which I never found except for the 3/16 line with 3/8 (7/16 flair nut) fitting for oneconnection on the master cylinder. I will try to document all this with a picture and details of what went where.
At the point of cleaning and ready to start reassembly. I am wondering if the power booster and master cylinder should be painted to prevent rust from taking over.They have already developed a red haze and haven't even put them out in the weather yet. We have had record rainfall over the last year, more than 22" above normal, and it seems to be on a weekend rotation. I work Monday thru Friday earning some spending money, and it stasts raining Friday and does not stop until Monday. Not sure if I should build a shed or a boat at this point to prepare for future well being and success in accomplishing anything.

 

No use painting the master cylinder, brake fluid eats paint like paint remover. You may be able to keep it coated with wd40 or something like that to keep the rust at bay.

The standard pre-flared lines you can buy that are 3/16 diameter come with the standard 3/8-24 threaded nut on the end. Sometimes like you found out, you can't get the right adapter for the pre-flared lines, so I just cut one end of the pre-flared line off, slip the old odd-ball nut on the new line, and then re-flare the line.

At least you got a roll of the good copper/nickel line. Like I mentioned it is soft and easy to run, so I would tape off the end of the line and then try to fish the line behind the fuel tank. You still may find it is very difficult to run the line to the rear in one piece from the proportioning valve to the rearend, but with careful planning you might be able to get it in there. The factory ran these lines right after the frame was put together with nothing in the way.

 

Urethane paints are resistant to brake fluid.

Eastwood makes a paint specifically for brake master cylinders.
https://www.eastwood.com/eastwood-br...y-aerosol.html

The Duplicolor 500° engine paint with ceramic is also very resistant to brake fluid.

So there are options for painting master cylinders

Prep is important though be sure to wash the area to painted thoroughly a couple times with acetone.

 

I use Fluid Film on the master, booster, brakelines, proportional valve...from master to every wheel...calipers, back plates. Basically the entire brake system. Don't use it on rotors, or inside the drums. You can treat the inside of the backplate, wheel cylynders, etc. Not the shoes or drum. After treatment to remove rust be sure to use brake cleaner to remove it from inside the drum. Then lube the backplate and adjuster with brake grease.