How to change a master cylinder on 99 e250

I do agree with the haynes manual.

First off, pb blaster is your best friend for brake line bolts. You want to **** as much of the brake fluid out of the resivour as you can, Then you need to get the brake lines off the master cylinder that is on there. make sure you use the right size flare nut wrench when you are taking the lines off. rounding off brake line bolts is not fun, trust me. once the lines are off, ( turn counter clockwise) Just make sure you have a towel to put under the brake lines. for excess fluid. then with a ratchet, and extension, and socket you need to take the master off the brake booster. Also disconnect any electrical connectors and keep them clear ofthe brake fluid. When you have the 2 bolts out of the brake booster, the master should pull out and then your ready to work on installing the new one. when you get a new ,master, you can either bench bleed it, or if you want to, you can also install the new one, line up the hole in the brake booster, put the 2 bolts back on, then you need to bleed the master. Most come with instructions.

1. Begin by removing the cap.
2. Follow the directions that come with the kit to select the suitable adapters, and then connect the adapters and tubes to the ports on the cylinder. The other ends of the tube extend down into the master cylinder, and are held in place by a plastic clip.
3. With the bleeder kit installed, fill the master cylinder about halfway with new brake fluid. Use a large screwdriver to depress the valve assembly inside the master cylinder. If you do not have a vise you can mount the master cylinder on the vacuum brake booster and bleed the master cylinder.
4. Small bubbles will appear in the fluid. Continue working the valve assembly until no more bubbles appear. This indicates that the cylinder has been thoroughly bled.

once it is bled then you hook up the brake lines, and bleed all the brakes. starting with the furthest from the master cylinder. Passenger rear, driver rear, passenger front, driver front. make sure you check the brakes to make sure there is no air, better to be safe then sorry. also, check anything you had disconnected, to make sure it is not leaking.

In simple terms, by just looking at it, you can figure out how to do the master cylinder, but to be safe, get a repair manual.