rock hard brake pedal

Been driving my Jeep a little since I finished the 4 wheel disc conversion. The proportioning valve took care of the rear tire lock up problem. The brakes seem pretty good except for the brake pedal. It goes to a certain point then get rock hard. I had the same issue with my drum brake and I'm a little disappointed to still have it. The only thing in the entire brake system I didn't replace was the master cylinder. I thought about using the one off the Caddy I took the rear brake off of but hoped I wouldn't need it. It's weird because the pedal travel seems normal but after a certain point it makes no difference how hard I push on the pedal it just stays there. It went to the floor while I bled the brakes so it's not like it's binding and physically won't go any farther. It just seems like the master cylinder is building up pressure that doesn't make it to the calipers. Anyone ever had a similar issue? Cold as heck here so I won't be driving much for a few days so any input would be great????

 

REALLY wierd. please let us know what you find out, never heard of such a thing.

does your jeep stop when you hit the brakes? its not a matter of not having the 'strength' to clamp the brakes is it?

 

The brakes are pretty good I guess. I drove it on in the snow last week trying to get the proportioning valve adjusted. If I really stood on the pedal it would lock up all four. It just seems weird because the pedal hits a point that almost no matter how much harder I push it doesn't travel much further. On my gpw, with all drum brakes, if I stand on the pedal it will lock up and I can tell if I pushed harder it would go down farther. The white Jeep had always had a hard brake pedal with my drum brakes so I tried a different master cylinder. It didn't help so I sort of gave up and dealt with it. So after I swapped out my drum for all disc I couldn't believe it was still so stiff at about the same place. My pedal assembly is out of a Toyota Land Crzer. I didn't change the distance from the push rod to the pivot point but I did shorten the pedal arm about 3" from the push rod down. I'm a little disappointed because I thought I fixed it with the new brakes.

 

Just got off the Wilwood web sight. They recommend a 6:1 ratio for a non-power assist brake system. The means 100lbs on the pedal will be 600 on the master cylinder. The GPW with an old Chevy truck pedal assembly is right at 5.3:1. The white Jeep with my modified Toyota pedal assembly is only 2.25:1. That really tells the story. I either need to gain alot of weight and start doing leg curls or I need to move the pivot point down closer to the push rod. I did not change that but I did cut several inches off the lower arm. That drastically changed the ratio. The Toyota swinging pedals were the longest I had ever seen but they are extremely well built so I used them. Now I can move on to the next phase of this brake upgrade. No good way to do this except to rip the whole thing out from under the dash and fix it. Oh well the weather here still reeks so I will get started asap.