No Brakes - how hard to replace master cylinder plus lines?, looking for some guidance before I dig into my manuals... Options

[potomacmidget]

Merry Christmas everyone,

So, my brakes have been really soft, and I figured they were due a bleeding so I bought a pressure bleeder (watched Ian Karr video) and put my car on jackstands and removed all the wheels. Topped off the reservoir with fluid, then when I inspected the master cylinder and observed it was visibly "wet" with what I could only suspect was fresh fluid. First thought was "ok, not good, that must be my pedal problem" then I reached in there with an open end wrench to see if I could snug the connection, and the tubing (vertical) was not even connected to the MC, it just swung away when I touched it, then all the fluid poured out. I guess the threaded part of the tubing rotted away in the MC?

Regardless - looks like I need a new MC, and will have to inspect/replace sketchy lines, etc., and all that comes with that project.

Prior to diving into my collection of service manuals, any guidance on the challenges of this job? Do's and Dont's? It looks a bit nightmarish to access the MC, and since my simple job turned a lot harder, I will wait until my garage is warmer than 30F. All advice appreciated...

thanks,
Reg

[fiacra]

Since you plan to do all of the lines, including the supply lines from the reservoir, I would install the lines and rubber plugs on to the MC first and feed them up to the MC reservoir. You do need to move the gas tank to do this, but you don't have to disconnect any lines or take it all the way out if you are not doing anything on the tank. Just prop it out of the way. Still, as already mentioned now is a good time to replace the lines under the tank, filter, sock, etc. Trying to seat the metal lines/plugs on the MC with it installed is probably the most frustrating part of the job so it is nice to be able to do it before installing the MC.

A few other things that randomly come to mind:

- Truly getting all the air out of the lines is a lot of work. I use a Motiv pressure bleeder. It is invaluable for this job, and has been a real help on my other vehicles. Lightly tapping the brake pressure regulator with a mallet can help free air bubbles. Bench bleed the MC before installing. I have gone through three quarts of brake fluid before being satisfied that all the air is out. You may not need as much, but they are brakes, the things that stop your car and (hopefully) keep you from getting killed or injured, so be sure.

- Don't forget you may need to replace the grommet above the MC that the metal lines go through.

- Make sure you have new copper washers for the banjo fitting. You can anneal the old ones, but new is better in my opinion.

- When replacing the rear soft lines the forward clip that holds them to the bracket looks near impossible to get off. There is a notch in the back of the bracket that you can't see that you can get a screwdriver behind to lever the clip forward so you can then more easily get it off. A Porsche mechanic I know puts vice grips on them and levers them off that way. Either way works, or come up with your own. I stared at them for a while before I figured it out.

- Finally, spend the extra money and get the ATE MC. I got my first one from a popular supplier on this board, and it turned out to be defective. Nothing fun about eating the cost of a part and then having to do this job all over again. Not trying to disrespect that supplier, I have lots of other quality parts from them on my cars, but that experience left a bad taste in my mouth. It was a poorly seated casting plug that leaked. And yes, I did contact them to let them know about the defective MC. I had the part for a few years before putting it in so I didn't expect a refund. They met my expectations there (IMG:style_emoticons/default/biggrin.gif) .

- You have already discovered that PMB is your friend in this process. High quality parts, responsive, and willing to answer questions. They get my money every time if I have a choice in suppliers.

- If you have a 17mm MC that you are replacing with a 19mm MC (which you should do) don't forget that it will feel different. You will need more force on the brake pedal. Don't be freaked out by that. You'll get used to it.

Good luck!