929 m/c write up
 

this is my first time doing a write up, i hope i didnt leave anything out and its easy to understand. i hope this will help some of you

items needed:
929 master cylinder
1 or 2 12 inch brake lines with metric inverted flare
10mm flare nut wrench
14mm flare nut wrench
12mm wrench
philips head screw driver

first you should put rags beneath your master cylinder because you dont want to drip brake fluid on any of your paint. then remove the brake lines going to the top of the brass fitting, remove the line going for the hydraulic clutch, disconnect the fluid level sensor.
https://i5.photobucket.com/albums/y2...s/PICT2645.jpg

then remove the 12mm nuts holding the m/c to the booster. now you can remove the m/c from the car. once removed remove the screw that holds the reservior on the m/c, and put the reservior onto the 929 m/c.
https://i5.photobucket.com/albums/y2...s/PICT2647.jpg

here you can either use two custom brake lines or you can use one custom line and the rear brake line off the rx7's m/c. i took off the brake line from the back of the rx7s m/c and used it for the front line on the 929s m/c. if you use the brake line from the rx7s m/c use new washers with the banjo bolt. then i made a custom line for the back. i got my brake line from a local auto parts store for $5 with fittings on it already. i just had to bend the line. torque the brake lines 10-15 ft-lbs
https://i5.photobucket.com/albums/y2...s/PICT2650.jpg

connect the lines to the brass fitting
https://i5.photobucket.com/albums/y2...s/PICT2654.jpg

now you should bench bleed the m/c. if you dont do this you may never be able to get all the air out. after you bench bleed the m/c its time to install it on the car. it goes on the same as the rx7 one so theres nothing tricky
https://i5.photobucket.com/albums/y2...s/PICT2651.jpg

once its on its time to bleed the system.

https://i5.photobucket.com/albums/y2...d3s/motivr.jpg

my initial impressions: i love it! im using the stock brakes, and they feel so much better. i havn't tried anything too highspeed yet, as i want to make sure the lines wont fail on me first. i've done a lot of stops from about 50mph, activated the abs a few times, and the pedal feels great. less travel, and a firmer pedal. you dont even notice the extra pedal effort.

good job!

:icon_tup:

that brake bleeder looks pretty cool, did it work well for you?

http://www.motiveproducts.com/02bleeders.html

nice..

nice write up! thanks for putting in the time to write up with pics. Im sure it will help many.

nice write up! thanks for putting in the time to write up with pics. Im sure it will help many.
btw how much and where did you get the 929 part.

that was my first time using it and it worked great. i highly recommend it

i got it from mazda, it was like $200 without a core

Great writeup man. Keep it coming. You ROCK!

I put a 929 mc on my 7 ,the only difference in the install was I did not need any new or custom lines and none of the lines needed bending .I modified the cylinder to bolt in as the stock one .I did polish it as well . Nice write up and pictures .Good that you took the time to help others .

Nice!do you happen to have the part number for the mc?

hg31-43-400r-0g

Thanks!

thanks for the writeup

Hell of a job on the write-up....great info:bigthumb:

Just wanted to thank Azn Akira again for this great writeup. Let me add a few things from my own experience:

1) The 12" line is absolutely perfect. At Pep Boys and Kragen the part number is BLJ-312, or simply ask for a 12" Japanese steel brake line with flare ends.

2) Pulling the reservoir off and putting it back in can be tough. I decided to use the 929 reservoir (because I have a separate clutch reservoir) but even then I accidentally tore one of the seals installing it. Make sure you spread some brake fluid on the reservoir nipples and the seals before installing to reduce the chance of damaging the seals.

3) With the banjo fitting, don't bend the line with the copper washers in place. You can wind up compressing them in such a way that the line will leak.

-ch

Good info. Here is Crispy's take on it also: http://www.negative-camber.org/crispyrx7/929.htm

Hyperion - how did you replace the seal you tore?

Re bench bleeding:

Put the MC on the car, get a cheap ($10) MC bleed kit at autozone.
The kit is just various fittings and hoses.
Connect the hoses, route them into the reservoir.

Have a buddy hold the hoses so they stay in the reservoir, and pump the brake pedal gently, until no more bubbles are seen.

Much easier than bleeding in a vise.

was this from a 88-91 929?

From Crispy's site in my link above:

"The Master Cylinder

Where can one source a larger master cylinder that does not require a complete redesign of the stock system? Mazda has been kind enough to accommodate our needs. The master cylinder from a 1993 Mazda 929 ABS equipped sedan (pn: HG-31-43-400G) fits almost perfectly. These can be had for about $170 new or about $100 for a rebuild. The 929 master cylinder uses a 1" piston vs the RX-7 unit which uses a 15/16" piston as can be clearly seen in the picture above. It's cast right into the master cylinder body. "

Dont forget the most important part of this swap is taking the old bushings out of the old unit (the rubber rings that seal the resivior and to put them on the 929 or you'll get leaks.

I just switch my stock master cylinder to a 929 master cylinder. But I have an issue I don’t know if it’s a normal issue that I might just have to let the car idle for some time to ree-vacuum the system or what. My issue is when I let the fd idle and hit the brakes the idle will drop about 300rpm and come back up to normal until I hit the brakes again. It will do that as many times as I hit the brakes. Keep in mind I didn’t have this issue before with the stock unit until I switched to the 929. Some one please help me out on this thanks.

Is the check valve still in the booster vacuum line?

I am pretty sure it is as i never removed it. Can it fall out

No, but it could get stuck. Blow into the line, the check valve should prevent flow in that direction.