Bad Master Cylinder?

[m3x1c0]

Hey guys. My pedal went to the floor again (this car hates stopping.) I was only a minute away from my buddies house so I pulled in and looked at the MC only to find a tiny bit of fluid in the front reservoir. Not sure if it went dry but seems possible. Turns out my right rear wheel cylinder was peeing all over. Car sat for a week or two and last night I threw in the new wheel cylinder. All the pads and hardware were in good shape just needed the cylinder.

Now my question. The pedal still feels pretty spongy to me after bleeding the old fashioned way (a rag, a socket and a mess.) Not sure if I just need to bleed it more or if my MC is bad. The MC was replaced about 9 months ago. Whats making me think its bad is that when I step on the brake I can see inside the MC is shooting fluid up at the lid. I've been told this is a symptom of a bad MC but I suppose it could also be due to air in the system.

Thought I bled them pretty ok but those stupid sunk in bleeder screws in back don't give me confidence. What do you guys think?

 

[dr..mach]

I'm leaning toward air in the system. I use a hand held vacuum brake bleeding pump that has always worked really well whenever I have a soft pedal. Make sure you bleed all 4 in the proper order. I'd start there as that will only cost you a little time.

 

[m3x1c0]

I'm leaning toward air in the system. I use a hand held vacuum brake bleeding pump that has always worked really well whenever I have a soft pedal. Make sure you bleed all 4 in the proper order. I'd start there as that will only cost you a little time.

Ill probably go with the hose into coke bottle technique costs pennys.

 

[whitehot1]

You can get a one-man-brake bleeder kit from Autozone for about $9.00 and it works great for what you are doing. Really simple and easy to use for one person brake bleeding.

 

[87geeinn]

You can bleed the brakes all day long but if the fluid was low enough to uncover the holes in the MC, then you likely have air in the MC. Best to remove the MC and bench bleed it. Fluid shooting up when depressing the pedal is normal. You'll see this if you ever bench bleed a MC and push the piston in too fast.

 

[larrym]

 

[TexasT]

X2 on bleed it again. Start at the mc. I bleed em on the car, but it isnt just cycle it a few times and call it good. Put your eye protection on, put a 2x4 under the pedal and recruit a pedal pushing helper that understands push and hold, and release. Then have your fluid ready and start with the master cylinder. Cycle the pedal until you don't see any, even tiny bubbles in either reservoir. Then move to the pass rear, bleed it until it doesnt blow bubbles. I use a glass jar and some tubing. I loosen the bleeder, feed the tube through the socket so you can open and close the bleeder by hand while bleeding then tighten it back up and move on to the driver rear, then pass front and driver front. You need to keep topping off the mc as if you run it dry you must start over.