This is my first time replacing a brake master cylinder on my 1995 NA Miata track car.

Questions:

1. I'm going to reuse the brake fluid reservoir on the new master cylinder. I see a screw at the base of it holding it to the master cylinder. Removing the screw I assume the reservoir can just be pulled off. Correct?

2. During the bench bleeding process, what do you do with the proportioning valve return line port? Do you cap it during the bench bleeding process or connect a small line from it to the open reservoir like the two pressure lines in the front of the master cylinder.

Thanks Folks!

George S.

 

All three of the lines coming off the MC are pressure lines - two to the front brakes, one to the rear. All three get routed back into the open reservoir.

 

1. yes just the screw. it can be stuck in there pretty good through even after you remove the screw.

 

I've never bothered with bench bleeding. Yeah, you put a bit more air through the lines, but everytime I've changed the MC, the entire system needed flushing anyway.

 

I forgot to bleed my new master in my car. I couldnt get the bleed to take at the calipers. I had to go straight for the tube nuts on the master and get fluid to come out of those with the nuts loosened first.

 

Were you using a power bleeder or similar? I've absolutely never had luck with those, I bleed brakes/master the two person way, and it always works great.

 

I was going the two man way. I also replaced every single line, except for the rear two hardlines and the rubber lines and added an abs brick so the car was basically completely bone dry.

 

Ahh, I bet the ABS module was part of the problem.

The last time I did it = new master and 4 new Wilwood calipers.

 

wilwood 1" master has bleed ports directly on the MC

 

Well, that's really f_ckin' convenient.

I changed out my master and rubber lines. I installed Earl's speed bleeders so I'm hoping I can just pump away while drinking a beer ... I hope.

-Zach

 

Well I got it installed. I bench bleed it but I'm sure a lot of fluid leaked out as I reinstalled lines.

What may be a neat trick I read about and used to initially bleed the master cylinder in place was to depress the brake pedal only 1/4 inch and a single bubble will float up in the reservoir from the MC. Repeat till all the air is out.

I'm going to follow up with a two person bleeding drill starting at the the three MC lines,

Thanks Again.

George S.

 

As long as the reservoir didn't empty out, you should be good.