Does anyone know how to do this? My ASE Certified Brother-in-Law (Who Hates Me) said that I have to "Bench bleed" my new brake master cylinder before I install it into my '80 RX-7. He says that if I don't, installation is a royal pain in the ***... Anyone have a clue as to how to do this?



Thanks in advance!

 

There will be nipples on both outputs, take small hoses and run them back into the master cylinder, then clamp it in a vise, fill with fluid, get a punch or something that will nicely fit in the booster/pedal side of the master cylinder, start pushing until no air comes out of the tubes.

 

he said nipple. i just let it start leaking fluid out of the master, from the fittings.



basically the idea is to get the air out of the master, can be hard to bleed otherwise

 

Same way as brakes. Pump and hold then losen nipple close and repeat. If you can not get a firm pedal there may be air traped in the fitings. Pump hold and brake one of the hard lines lose till it spews out. Air should come out, repeat this and change lines if needed.



^ if you don't prime it well thats what you need to do.

 

the last mc i bought actually came with a bleeder kit, plastic pieces that screw in where the lines do and clear plastic hoses that attach to those with the other end going back into the resevoir. bench bleeding can actually be done with the mc mounted on the car, before putting the brake lines on it. i do it all the time. what i will be doing in the future is cutting some brake line from the mc off a junker and bending them to run back into the mc as my own bleeder kit.

 

The quick and dirty way is to hold your fingers over the outlets while a friend pumps the pedal.

 

I'm glad to see this topic. My '80 7 has never felt as firm as think it should despite repeated bleedings both by me as well as professionals. When they first installed the new MC and new lines, I wonder if they didn't bench bleed the MC. I'm interested in knowing more about how to do it on the vehicle before my next track event. Details, Details, Details!!!

 

bench bleeding the MC needs to be done before the hard lines are hooked up to it. in your case, if the new MC wasn't bled before the lines were connected, it has air all thru the system. if u had a mechanic do it, they probably used what's called a power bleeder, which is a canister that has a rubber bladder in it. top half has brake fluid in it and the bottom is compressed with air. when connected to the MC, the valve is opened forcing fluid thru the complete system, removing any air. have you tried adjusting the rears?