No front brakes

[LaJ10]

Ok I have had this problem since I got my truck today I finally decided to tackle it.I changed the master cylinder and bleed the brakes .Still no front brakes !!!!!!!!!!!!They do work but just have no real stopping power.The back brakes work great and will lock up the tires no problem but the front will not lock up.The peddle goes down and gets stiff but still the front brakes dont hold well.Am I missing something here?I have heard of the button (for lack of a better word) on the front of the com vale and the first time I held it in,no help.So the second time I pulled it out .Still no good.Somebody help me please !!!!!!Has anyone got any suggestions.Pics of the 2 different com valves would also be helpfull.

[Mud Thrasher]

What shape is the rubber brake hoses in that are going to the calipers? When they get old they will dry rot and when you press the brakes they will swell and not fully engage the front brakes. I would almost bet that is it. That or you have a kink in the line.

[Sitting Bull]

Did you bench bleed the master cylinder? The prop valve is one of those things that gets the blame for 95% of brake problems, when it only causes 5%. Are you getting good pressure when bleeding at the front? Do you have to pump a lot to get the pressure? Will the pressure hold once it is pumped up? In short, we need more info to help.

[LaJ10]

I checked the brake lines .No signs of swelling or leaking or kinks or binds.I did bench bleed the master cylinder.Pumping the brakes makes no difference in how my brakes work.The peddle gets hard but the front brakes just dont hold tight.I did get some pressure at the front bleeders but not as much as at the back.Could someone ,previous owner,Have possible reverse the brake lines.I know they are the same size at the master cylinder but am not sure whenthey come out of or into the combination valve.

[Mud Thrasher]

They wont swell until you press the brakes laj10

[LaJ10]

I had the wife pushing the brakes.checked everything then bleed them.

[Glenn_tx]

Frozen calipers? Hit'tem with a hammer.

[LaJ10]

nope calipers are moving just dont get enough pressure to really do a whole lot.Any more suggestions?

[andy d]

it may be that the lines got switched, the front brakes should be connected to the port that goes to the larger chamber on the m/c. i replaced the m/c in my 83 a long time ago, so my memory is hazy. but i would think that the way the lines are formed would give a good indication of where they went. just for grins swap em if you can and see what happens. good luck