Brake problem! HELP!!!

[UtXjXtream]

Heres a scenario for you guys.(tried searching but function is down). After exploding a factory brake line I switched to steel, When I bleed the breaks I have perfect preasure in all 4 bleeders, When I bleed the MC perfect preasure in both lines(bench bleeding and mounted). When I start the vehicle it goes right down to the floor and all it does is locks up the rear tire(driver side). What are some cures you guys might have? I've tried everything and after all that still no brakes im baffled. Thought it might be the MC but want some imput before I go spend 150$. Any suggestions, hints, Ideas are welcome(PLEASE HELP ME). Thanks in advance


Xtream

 

[Lincoln]

Sounds to me like you still have air in the lines. Make sure there aren't any leaks either, but it sounds more like air to me.

 

[Bronco]

I’m not perfectly clear on how the system works but I think if you are getting rear brakes your MC is good. My logic being that if its making pressure in the back (or anywhere) it works. Could the problem be with the proportioning valve? Air in the line would be where I would start if I had opened the system at all.

 

[massxj]

what year xj iv been told a few years have vacume pumps /motors for the brakes

 

[UtXjXtream]

its a 1990. Thanks for the help so far guys, Any other advice is greatly appreciated. Thanks in advance.

XjXtream

 

[UtXjXtream]

BTT...Thanks guys

XjXtream

 

[Bronco]

Have you bleed the system till you get clean fluid at all 4 wheels and no bubbles? What method do you use to bleed them?