Brake Bleeding

[phat46]

I replaced a broken brake line on my daughters car today. the line to the drivers side rear had split and she was running on two wheel brakes. I replaced the line o.k. and bled that wheel cyl. The pedal was still low so i went to bleed the other rear wheel  and it won't bleed. When the bleeder is opened and the pedal is depressed it is just a little pulse and virtually no fliud movement. Several minutes of bleeding resulted in a thimble full of fliud being pumped out. Seems like I have read somewhere that the propotioning valve will over center or domething when you go low on fluid and has to be reset somehow. Any ideas? That wheel also seems to be dragging, maybe the wheel cylinder is bad?

[Carnut]

My guess is bad wheel cyl.

If prop valve was problem, other rear wheel wouldn't have bled.

[phat46]

My guess is bad wheel cyl.

If prop valve was problem, other rear wheel wouldn't have bled.

I should have mentioned in my first post that the car is a Mercury Topaz (Ford Tempo) It has a separate line to each wheel from the master cylinder/prop valve. That is, there is four outlets on master cyl, each to a different wheel.

[enjenjo]

Check the rubber hose on that wheel, It's probably swelled shut. I've had it happen before on them.

[wayne petty]

the topaz is a split diagnol system....  right front and left rear... left front and right rear...edit  oops... wrong.. four lines direct from master to the combo block..  still sort of a split combo system...

you almost have to use a vacuum bleeder on these units ....

or a pressure bleeder.. a pressure bleeder can be a 2 quart hand sprayer from the home center.. and a rubber plug in the top of the master...

it is also possable that the master has traveled through a rough unused patch in the bore and cut the seals...

i seem to recall that there is a combo valve for each rear line ....

check figure #1
http://www.autozone.com/az/cds/en_us/0900823d/80/12/81/53/0900823d80128153/repairInfoPages.htm


tons more stuff there.... and if you end up replacing  the master cylinder... install the lines before you bolt it to the power brake booster...  since they are 10mm thread and as i recall fine pitch... like 10mm X 1.0 they are easy to cross thread... i used to run across bolts from cars that were grade 12.9 that were that thread... i always saved a nut and bolt threaded together in a drawer in the rollaway..   they came in really really handy when someone made a mistake...as a tap will just screw everything. up....


and ... i forgot who posted the thread... was this car exposed to sub 0F temps?  brake fluid is alcohol and glycerine... and absorbs moisture from the air... this is why it is nice and clear (water white) when first opened.. and turns amber/yellow after use or when the bottle has been opened and left loose...i was thinking that if it was exposed to sub 0 and the fluid was old the extreme temp could have frozen the water in the fluid and broke the side out of the line...  or it could have just rusted out...

[rooster]

I replaced a broken brake line on my daughters car today. the line to the drivers side rear had split and she was running on two wheel brakes. I replaced the line o.k. and bled that wheel cyl. The pedal was still low so i went to bleed the other rear wheel  and it won't bleed. When the bleeder is opened and the pedal is depressed it is just a little pulse and virtually no fliud movement. Several minutes of bleeding resulted in a thimble full of fliud being pumped out. Seems like I have read somewhere that the propotioning valve will over center or domething when you go low on fluid and has to be reset somehow. Any ideas? That wheel also seems to be dragging, maybe the wheel cylinder is bad?

I had something simular happen when working on the sons s-10! To get the spool in p-valve in right position I opened the front bleeder all the way and spiked the brake pedal 1 time , that re-positioned the spool and things would bleed right.

[rooster]

I replaced a broken brake line on my daughters car today. the line to the drivers side rear had split and she was running on two wheel brakes. I replaced the line o.k. and bled that wheel cyl. The pedal was still low so i went to bleed the other rear wheel  and it won't bleed. When the bleeder is opened and the pedal is depressed it is just a little pulse and virtually no fliud movement. Several minutes of bleeding resulted in a thimble full of fliud being pumped out. Seems like I have read somewhere that the propotioning valve will over center or domething when you go low on fluid and has to be reset somehow. Any ideas? That wheel also seems to be dragging, maybe the wheel cylinder is bad?

I had something simular happen when working on the sons s-10! To get the spool in p-valve in right position I opened the front bleeder all the way and spiked the brake pedal 1 time , that re-positioned the spool and things would bleed right.