Mazda truck brakes

[wlkjr1951]

My son and I changed the rotors and pads on his 91 Mazda truck and now we can't get any pressure. We filled up the master cylinder and started bleeding the lines. Then the m/c just lost pressure. We loosened the lines at the m/c and can't get any fluid out. What are we doing wrong?

 

[97f150]

Think maybe you may need a new m/c.

 

[michael harris]

Well when you changed the pads and rotors what did you do to the calipers..? w/ the exception of pushing the pistons back a bit they shouldnt had much done to them. It's obviously something you have done, just need to know what all you've done??
44H

 

[wlkjr1951]

All we did was push the piston back with a C clamp replace the rotors, install new pads, and fill up the m/c with new fluid. Started bleeding the lines and it lost pressure. The book said to bleed the m/c so we tried loosening the lines right at the m/c but can't get fluid to bleed out.

 

[beanoil]

quote:

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Originally posted by wlkjr1951:
All we did was push the piston back with a C clamp replace the rotors, install new pads, and fill up the m/c with new fluid. Started bleeding the lines and it lost pressure. The book said to bleed the m/c so we tried loosening the lines right at the m/c but can't get fluid to bleed out.

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Just a guess, but possible that dirt was pushed from the line into the MC and has lodged in a seal. A basic explanation of MC's is on POPMECH
Good luck.

 

[wlkjr1951]

Beanoil, thanks for the link. I read it over and we backed the truck up a hill to get the m/c level and that did the trick. It would then blow my finger off the bottom hole in the m/c and purge fluid. Connected it back up and did a thorough bleeding and now have a full pedal. It will stop on a dime and all for about $55. The old rotors were shot.