WE JUST GOT A AND HAD TO REPLACE THE M/C AND THE HOSES.
1989 Jeep Cherokee
May, 23, 2012 AT 11:35 PM
We bled the brakes with no results. We have tried several times now to no avail. The brakes themselves look fine. The pedal will get tight but if you leave them alone for 5 minutesm they go straight to the floor again. They also fail when we start the ignition. Why?
You still have air trapped. Pressure bleeding from a shop may be the answer.
Did you replace the master cylinder?
May, 23, 2012 AT 11:41 PM
Yes we did. We have been continuously bleeding for 30 minutes each times and have tried 4-5 times now. Could air still be trapped?
May, 23, 2012 AT 11:43 PM
You sure it not leaking anywhere such as the wheel cylinders
May, 24, 2012 AT 1:03 AM
I'LL THROW IN (RATHER PASTE IN) MY ANSWER!!!
My Bench bleeding ain't on the bench...it's on the vehicle!
Much EZer that way!
This can be done on the vehicle (my preference) using two people, one pumping really slowly and one monitoring the Master Cylinder.
I wrap string loops around the little hoses that attach to the plastic bench bleeding adapter and tie a knot, as to keep the tubes from blowing off of the plastic adapters.
I keep the two plastic lines submerged in the master cylinder, at all times.
I take it one step further, by squeezing the little hoses with my fingers (as if "I" were a check valve) The VERY SLOW PUMPING OF THE PEDAL will push the fluid into the reservoir, SCOOTING BY MY PINCHING, but the pinch will not allow it TO S.UCK AIR BACK, as you see in the beginning of this video (he is not pinching the lines, makes it take longer to remove the air)....My way makes things faster, but if you did not tie the hoses to the adapters--THEY WILL BLOW LOOSE (lots of adjectives will be bust loose out of your mouth!)
This is very similar to my way, and is a good video showing this being done on the vehicle
Once the "MC" is "air free"---this is the procedure that has worked for me......forever!
This is the basic bleeding procedure I use:
KEEP FLUID IN THE RESERVOIR AT ALL TIMES/ CONSTANTLY CHECKING!
START WITH FURTHEST OUT WHEEL CYLINDER, FROM THE MASTER CYLINDER, WORKING TO THE CLOSEST (RR, LR, RF, LF)....THIS WILL CHANGE IF THE VEHICLE IS "RIGHT HAND DRIVE"
2 PEOPLE, ONE PUMPING, OTHER BLEEDING AND REFILLING
#1 man is the Bleeder
#2 man is the Pump Man
1-MAN BREAKS BLEEDER LOOSE-SNUGS IT BACK CLOSED (THIS SORTA KEEPS HIM FROM FIGHTING IT, WHEN HE IS READY TO ACTUALLY BLEED IT) THEN HE YELLS, "PUMP IT UP"
2 MAN-PUMPS 6-8 TIMES (YELLS "PUMPING"), THEN HOLDS PEDAL--YELLS, "HOLDING"......ANY MORE PUMPING IS FRUITLESS
1-MAN CRACKS BLEEDER...AIR/ FLUID SPURTS OUT OR WILL EVENTUALLY
2-MAN YELLS, "FLOOR" JUST BEFORE IT ACTUALLY HITS THE FLOOR (THIS GIVES #1 MAN SOME TIME TO TIGHTEN, BEFORE IT DOES HIT THE FLOOR)
1-MAN TIGHTENS THE BLEEDER....WHILE IT IS STILL SPURTING OUT (NOT AFTER IT STOPS...OR IT WILL SUCK AIR BACK IN).....THEN YELLS, "OKAY---PUMP IT UP"
THIS PROCESS STARTS OVER AND OVER UNTIL YOU ARE SATISFIED, WITH EACH WHEEL
THIS DOES NOT MATTER WHETHER THEY ARE DRUM BRAKES OR DISC.
ON DRUM BRAKES:
YOU SHOULD ALREADY HAVE THE SELF-ADJUSTERS PUSHING THE SHOES CLOSE TO THE DRUMS, SHOES SLIGHTLY TOUCHING THE DRUMS , BEFORE YOU DO THE BLEEDING PROCEDURE.....THIS WILL KEEP YOU PEDAL AT THE TOP AND TIGHT. DO NOT OVER ADJUST!!!(WE'LL GET INTO THAT PROCEDURE IF YOU NEED ME TO)
I PREFER THIS OVER USING THE ONE MAN, HOSE AND CUP, METHOD WHERE YOU SUBMERGE THE HOSE AND PUMP....TO ME THIS IS FASTER AND MUCH EZer. GRAITY BLEEDING HAS NEVER WORKED FOR ME