Master cylinder

[FAHRENHEIT451]

When do you know it's the Master Cylinder? My brakes work buttttt......the brake pedal has some play before I can sense the brakes are engaging. It is not the same squishy feeling that you get with air in the line, or is i?. That instant response you get when you just start touching your pedal is not there. I just purchased this 2005 Liberty with 80k miles on it. I guess I'll bleed all lines and if that doesn't work then replace the Master Cylinder?? Any ideas?? The Booster??? What is the proper process of elimination?

 

[54cj3b]

check prop valve also check for small wet spots aka leaks all connections and fittings than go for major stuff last

 

[SteelHeadz]

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Yep check those. A tell tale sign that the brake booster is failing is a hard pedal. A low pedal would also indicate an internal leak in the master cylinder if an external leak is not evident. Try bleeding it first and see if the pedal height changes.

 

[superj]

also, hte rod might be mis-adjusted from the pedal to the master. my cherokee had brakes all the way on the floor with all new parts. turned out hte rod was not adjusted properly. you are supposed to have 1" of pedal swing before you can feel the rod engaging the master cylinder. there is an adjuster at the tip of the rod that is in the master cylinder, shaped like a bullet. it can be screwed in or out to move the engagement point up or down

 

[vickery_ray]

also, hte rod might be mis-adjusted from the pedal to the master. my cherokee had brakes all the way on the floor with all new parts. turned out hte rod was not adjusted properly. you are supposed to have 1" of pedal swing before you can feel the rod engaging the master cylinder. there is an adjuster at the tip of the rod that is in the master cylinder, shaped like a bullet. it can be screwed in or out to move the engagement point up or down

Is there a way to check the rod or adjust the rod without disconnecting all the hoses to the master cylinder? i jusr replace the rear brake pads in my 2000 jeep grand cher and can smell the brakes burning on the rear right passenger side again?

 

[superj]

yes, just undo the nuts holding the master to the vacuum booster and slide it off enough to see that rod. that is how i did my cherokee till i got it right and since an upgrade for me is to use a grand cherokee booster, it should work for you also

 

[SteelHeadz]

If the right rear caliper is locking up, the master cylinder is NOT a likely cause otherwise both rear brakes would be affected. I would suspect that the caliper is faulty. My 81 CJ7 started to grab a little bit harder on the left front than the right. After raising the wheels off the ground, i found that the caliper on the left front is partially locking up and requires a lot of effort to turn by hand. I replaced both fron brake calipers and problem solved. They were the original calipers from the factory.

 

[superj]

steelheadz is right, the rod adjustment is probably not going to help you with the back brakes getting hot. i was in a hurry and only read your first line.

 

[FAHRENHEIT451]

check prop valve also check for small wet spots aka leaks all connections and fittings than go for major stuff last

no leaks but thanks for advice!

 

[FAHRENHEIT451]

Sent from my iPhone using Tapatalk
Yep check those. A tell tale sign that the brake booster is failing is a hard pedal. A low pedal would also indicate an internal leak in the master cylinder if an external leak is not evident. Try bleeding it first and see if the pedal height changes.

No hard pedal and no low pedal, just no quick feel of the brakes when pedal depressed. They engage gradually when over a 1" depression is done. It must be the air....thanks for the advice!

 

[FAHRENHEIT451]

Everybody....THANKS FOR THE TIPS...will let you know how it turns out when I get some time to work on it !!!