Hello I did this last year on one of my master cylinder so I thought I would share

what is needed

one bad master cylinder with leaking lens

set of 18mm frost plugs from auto parts store advanced auto part # 362744.1

small amount of Loctite 680 retaining compound


now this is going to sound wrong but this is what worked for me

Put the frost plug in the wright way cup in by pounding with hammer
and steel piece of round stock or socket
after it is in put a screw driver on the in side and push it bake out
it should push out easy. You just re sized the frost plug to your master cylinder
now put a small amount of Loctite 680 retaining compound on both surfaces
you can try to reuse the o-ring but it my just squirt out on the inside of the master cylinder
and its not needed.
now put the frost plug in backwards cup to the inside of the master cylinder
tap it in with hammer flush to the out side

now take a ball peen hammer or a ball bearing and peen it in and make a small cup
there you go all done

Note you should give it 24 hr for the retaining compound to set

thanks for looking SpeedChaser

next

I just wanted to say thanks and add that I did this too and it really seems to have worked. I also have a current part number from Napa, because it took them a bit to find the part.
Napa part number 381-2153
Now if I could just get the damn things to bleed at all I'd be happier.

They will bleed easy if you have everything set up correctly. Mine did.
The important part here is that your master cylinder seals are new or at least working in the first place.
Then you must make sure that the arms are not pushing down in any way on the master cylinder.
You may have to adjust the cables back, back out the screws on the back of steering wheel, and remove front steering wheel face and reset your handles so that you get FULL stroke on the master cylinder.
If you are not getting a full stroke then you are just pushing too little fluid and wasting your time. You can find out what full stroke is by removing the cable on master cylinder and pulling the little lever by hand. Note how far it must travel. Now hook everything up again and adjust what you have to so that you get FULL master cylinder stroke.
I found that on my machine that I just rebuilt that I had to actually reset my steering wheel brake levers so that I got the full stroke. This makes you reach a bit to be able to grab them. On my other two machines we don't have them set out that far but they are already bleed so very little movement is needed to lock the brakes. I guess you could get them bleed and then set your handles back if you don't like "reaching" for the brake lever.

Edit: Forgot to add one thing. Look up the "Death machine rebuild" thread and on page 2 is the rebuild of the master cylinder.

Better option than freeze plugs.....

viewtopic.php?f=37&t=17504&p=168370&hilit=amazon#p168370

Thanks guys. I have the brake cables completely off with a rebuilt master and I can't get fluid through the lines. I'll do some more reading, I'm going to go after it tomorrow, again.

I rebuilt a master cyxlinder last spring on a fixer upper! I used a dime, grinder the dime to right size, fill the lens hole with jb weld over that and have not had any issue.

I also was not able to get brake fluid through my front brake lines, rear was fine and bled ok. I will keep an eye out for your findings!