Dead Master Cylinder?

[79 surfwagon]

Today my Dad and i installed a new axle housing under the wagon. When we bled the brakes we couldn't get a good pedal. Nothing compared to what it was before the swap. We used all new lines, pads, wheel cylinders.

A test drive shows the car will stop reasonably well; kind of screeching the tires.... but the pedal is on the floor. Not nearly as good as before this axle swap. The car had an ever slightly higher pedal.

We bled the brakes again with no success. The brakes don't pump up (indicator of air) the pedal is just lower than before and if you are sitting at idle you can force the brake pedal all the way to the floor if you push hard enough.

I noticed where the master cylinder meets the vacuum booster it is seeping fluid. Not dripping, but the booser is definitely wet. It's wet kind of just under where the master cylinder bolts up and then it fans outward like an inverted "V". Is this an indicator or symptom of a failed master cylinder?

I can post a pic if needed... but I've parked the car and put the cover on it for the night. it will have to be tomorrow earliest before i can get you a pic of the seepage.

Thanks for any and all help; and i can definitly use the help!!!

 

[t5montecarlo]

seepage is bad

 

[bowtie81]

replace the master cylinder, and when you do that make sure you bench bleed the new one before you install it and if you have time gravity bleed the system.

 

[79 surfwagon]

Thanks, I will definitely bench bleed the new master cylinder before I install it.

I was planning to bleed all four wheels after installing the bench bled master cylinder.

What is gravity bleed?

 

[BMR Sales]

Gravity bleed is taking all your bleeders loose and letting gravity pull the fluid down and out. I've never done it that way, always just pump the pedaled 3 times slowly and cracked a bleeder loose. Two people of course. Other option is using a vacuum pump.

 

[bowtie81]

i've gravity bled before and it actually works good especially when you have lots of air in the system. just make sure you dont let the resevoir run empty.