To Brake or Not to Brake...

[Frankenstien]

1997 Mercury Mountaineer, Most times Brakes OK... some times to the
floor... Here the Skinny, 98% of the time Brakes function normaly, no
pulling good foot preasure, then for no reason you go to use the brakes an
your foot goes nearly to the floor , one pump and your back to normal.
This condition exists Hot or Cold, Wet or Dry ... I have taken the
following actions, checked wear on all pads, 75% + on all 4 Blead the
brakes... all 4 the fluid looked clean when I started ...looks a little
cleaner now no leaks, hear no Vacume leaks.. all 4 calipers actuate
freely. ... I changed the Pads about a year ago... I did not remove the
bleeder screw as it was suggested in some of the Posts that I searched, I
would have thought tho if my problem were related to bad fluid in the ABS
sstem it would have shown up long before now. any way kinda thumped on
this one... Things I have concidered but have since ruled out: Air in the
lines...
Lost Caliper Pin
Cracked or Broken Brake pad
Contaminated Brake Fluid
Leaking Calipers

Hoping one of the followers of this forum will have a clue as I no longer
have one... :-(

 

[Glassdude]

Sounds like the master cylinder to me. The symptom you described were the same I had on my '87 F250. Changed the mastrer cylinder. Solved the problem.

Mike

 

[Frankenstien]

Thanks for the Reply.... Hope Fully thats it... I have heard/read rumors of possible ABS propotioning Valve Assembly.... Big Bucks... on a Small Buck Budget....

 

[Frankenstien]

Well heres the up date... BTW this could affect any Vehicle not just this one... Turns out the Previoucs owner... or FOMOCO put the lines ont the wrong side... ie Front brake line, Left was on the right right was on the left, This would cause the Brake lines to stretch when turning, this is what gave the "intermitant problem... any way Put on new lines Blead the system.... Life is good now...

 

[DaveBen]

Happiness is brakes that work well.

Dave

 

[powerboatr]

Concur, sounds just like a seal in the master cyclinder. them little orings can be weird.

1997 Mercury Mountaineer, Most times Brakes OK... some times to the
floor... Here the Skinny, 98% of the time Brakes function normaly, no
pulling good foot preasure, then for no reason you go to use the brakes an
your foot goes nearly to the floor , one pump and your back to normal.
This condition exists Hot or Cold, Wet or Dry ... I have taken the
following actions, checked wear on all pads, 75% + on all 4 Blead the
brakes... all 4 the fluid looked clean when I started ...looks a little
cleaner now no leaks, hear no Vacume leaks.. all 4 calipers actuate
freely. ... I changed the Pads about a year ago... I did not remove the
bleeder screw as it was suggested in some of the Posts that I searched, I
would have thought tho if my problem were related to bad fluid in the ABS
sstem it would have shown up long before now. any way kinda thumped on
this one... Things I have concidered but have since ruled out: Air in the
lines...
Lost Caliper Pin
Cracked or Broken Brake pad
Contaminated Brake Fluid
Leaking Calipers

Hoping one of the followers of this forum will have a clue as I no longer
have one... :-(