Tony_22

Okay so I just changed my master cyliner because my clutch was acting up as it would stick to the floor and I would have to push it back up with my foot. Once I changed it though, it just slams to the floor and has no pressure at all. I have no idea what to do next as I couldn't find any tutorials on how to properly change a master cyinder. The most I seen was I had to bleed the air out but I have no idea where.
I know this may sound stupid but this is all really new to me and just need advice in this whole process.

mazdaverx7

iTrader: (6)

You will bleed the clutch hydraulic system at the slave cylinder. There is a bleeder screw on the top of the slave cylinder. The slave cylinder is located on top of the transmission on the driver's side. You will use DOT 3 fluid to top off the brake fluid reservoir, whichbfeeds the clutch hydraulic system.

UnknownJinX

When I bled it on the RX-8, I did it the two-man way. I had my buddy sit in the car, press and hold down the clutch, I unscrew the clutch bleeder screw in the engine bay a bit, some fluid come out, I screw the bleeder screw tight, and tell my buddy to pry up the pedal. Rinse and repeat, and add fluid into the reservoir as needed.

BTW DOT 4 and DOT 5.1 are also okay to use(they are actually better than DOT 3 but they cost more), just don't grab DOT 5 because it's very different from the other 3.

Tony_22

Okay but is my clutch supposed like just drop to the floor?
I feel like it needs to have some pressure to bleed it but it has nothing and just drops.

TeamRX8

iTrader: (25)

What model year is it? 2004-2005 had a bleed screw on the MC. They eliminated it in 2006.

Tony_22

I have a standard 2005 RX8

CaymanRotary

It's likely a leak in the slave cylinder. I had the same thing happen to me and yes it's normal if you have a slave cylinder leak. The slave cylinder needs to change out when you change the Brake Master Cylinder.

TeamRX8

iTrader: (25)

Sorry, I was thinking brake MC. The clutch MC doesn’t have a bleed screw. The recommended way to bleed the MC w/o a bleed screw is put fluid in it on the bench with short line(s) coming from the brake line connections back into the top reservoir opening plunge the MC piston in/out until all the air is removed from the recirculating fluid.

However, be advised that until you get most of the air out and have the bleed screw closed that during the bleed process the pedal won’t return on it’s own. You have to pull it up by hand. Once the system is fully bled and sealed, when you push the pedal down the system is pushing against the clutch diaphragm spring and then when you lift up off the pedal the diaphragm spring is pushing the fluid back and then the pedal also. When you’re bleeding the system the diaphragm spring is not being compressed/engaged. After you close the bleed screw with all the air out and then pull the pedal back, then when you press it again you should feel the spring pressure and it’ll return as it should.

this is how I bleed it myself without a speedbleeder, which I don’t trust/use. I open the bleed screw, go around and push the pedal down by hand, then go back and close the bleed screw, pull the pedal up by hand, open bleed screw, push pedal down by hand, and just go back & forth. However, I do use the speedbleeder catch hose/bag and before I do all that I just open the bleed screw with it attached and let that sit and gravity bleed first to get a lot of the air out first, which minimizes the back and forth. That also assumes no air in the MC because that isn’t going to get out by gravity. It has to be pumped out by the MC piston.

.

thebubbadog

Make sure you didn't forget the little press bar on the clutch peddle under the dash that goes into the fire wall. If it pushing into the fire wall into the little tube just try bleeding the air by removing the clutch from the floor maybe pumping it a couple of times holding it to the floor having you or your friend crack the bleeder valve and the close it after a sec and then pump and repeat the bleeding and hopefully who ever is under the car will start to see fluid coming out, I would recommend running a clear tube off of the bleeding nipple into a jar or something so you can see if air is coming out. If you never messed with the clutch under the dash I believe the little tube it push's in the fire wall was attached to the master and the bar could have fallen out

dannobre

iTrader: (3)

The easy way is a pressure or Vac bleeder... otherwise it can be really hard to get the air out. Especially with a new totally empty master

Cosmo Canuck

Did you bench bleed the new one? If not, it’s full of air and not fluid. I use Castrol GTLMA brake fluid in 90% of systems to keep moisture out. The wrong fluid (ie: old Dot3 that isn’t clear or contaminated with oil fluid) will do more harm than good.
I assume it’s a steel line system with compression fittings. If so, loosening the line at the master (with a rag or something to catch the drips that will eat paint) and bleeding there to remove all air bubbles should make it work again.
I had many Jeeps bend the clutch pedal “arm” so they pushed on an angle and we couldn’t get pedal until it was straightened out (and braced). It’s possible that might be an issue if nothing else helps.