ZJ brakes not working

[JIMBOB]

I recently swapped Ford 1/2 ton axles into my ZJ and now the brakes are very soft. I have to slam the pedal all the way to the floor to get it to brake. I've bled them multiple times and I am sure there is no air in the lines. My suspicion is that the stock master cylinder and reservoir are unable to pump enough fluid into the larger calipers. Has anyone ever had similar problems with axle swaps and how would I go about fixing it? Are there after market master cylinders that would be bigger or would I have to somehow adapt brake parts from a larger vehicle? Any advice would be great! I need to get this thing working again.

 

[jeep-N-montero]

My suspicion is that the stock master cylinder and reservoir are unable to pump enough fluid into the larger calipers. Has anyone ever had similar problems with axle swaps and how would I go about fixing it? Are there after market master cylinders that would be bigger or would I have to somehow adapt brake parts from a larger vehicle? Any advice would be great! I need to get this thing working again.

Your suspicion is correct, you need to upgrade the MC to compensate.