can't figure out brake problem (totally lost)

itsjustme

NAXJA Forum User

Location

tonoph, az

• Apr 9, 2012

• #1

I am working on a 1989 Cherokee with brake problems.
We have replaced almost everything and still have a mushy spongey pedal.
Almost to the floor.

It is a non ABS system.
Parts we have replaced :

Shoes
Wheel cylinders
Master cylinder
Power booster
Proportioning valve

Fronts looked good.
We have bleed the brakes many times but still no pedal. Any Ideas or tips ?

 

Last edited: Apr 9, 2012

T

Tacedaddy

NAXJA Forum User

Location

Shenandoah valley

• Apr 9, 2012

• #2

did you bench bleed the master?

 

Talyn

NAXJA Forum User

Location

Radford, Communistwealth of Virginia

• Apr 9, 2012

• #3

Did you bench bleed the master cylinder prior to install? Are your rear brakes adjusted properly?

 

T

Tacedaddy

NAXJA Forum User

Location

Shenandoah valley

• Apr 9, 2012

• #4

:laugh3: beat you

communistwealth of va... very true

 

itsjustme

NAXJA Forum User

Location

tonoph, az

• Apr 9, 2012

• #5

did all of that as well !! Adjusted the rears so there is a little bit of drag on them when you turn the wheel by hand.

 

techno1154

NAXJA Member

NAXJA Member

Location

In the islands

• Apr 9, 2012

• #6

Did you vacumn bleed them or did you use pressure? If left alone for a few minutes how many pedal strokes is needed to get a hard pedal?

You could be gettting air sucked into the lines from some where.
Is the adjuster rod on the master cylinder the correct length?
Take a look at the rubber hoses to see if they swell when pressure is applied.
Does the pedal get hard at all? If not, you may need to replace the master cylinder,...again.

 

K

Kevinma255

NAXJA Forum User

Location

West Milford, nj

• Apr 9, 2012

• #7

take out the stock master for the 89. throw it off the highest cliff you can find into the deepest ocean. replace it with a newer master and booster (think the cut off to the newer style that will work is 92 or newer but I am not sure). you will have to either space the booster from the firewall or modify the pedal to put the break pedal in the right spot. I have done this on two older xjs and my brakes have been unmeasurably better.

 

GrimmJeeper

NAXJA Forum User

Location

Gardena, CA

• Apr 9, 2012

• #8

try bleeding the lines at the master cylinder, sometimes air gets trapped up there because it's the high spot in the system. just have someone pump the pedal a few times and hold it then crack the line and close it again where it goes into the master. do it 3 times for each line, if that doesn't help you most likely have a problem with the master cylinder.

 

T

Tacedaddy

NAXJA Forum User

Location

Shenandoah valley

• Apr 9, 2012

• #9

if its not leaking anywhere and the brakes are new i would pull the master and booster from a WJ in the junkyard and bolt it in..
40 bucks and you can lock up all four tires

 

S

scottmcneal

NAXJA Forum User

Location

not here

• Apr 9, 2012

• #10

Look at the fronts, maybe mounted upside down.Just saying, heard about it.I think it was funny, but he is still BUTHURT over it.LOL.They did the brake lines on the rear axle to find this problem.I'm still laughing at it.Man he was/still is upset to this day.