jeepgrandcherokee4x4brakes

elg4llo · 03-19-2009, 06:49 AM

hi i have a problem with my jeep cherokee the brake are not workin wen the car is on they do wen is off bt i soon i start the engine the brake pedal gos to the floor i ha change the master cylinder but no it wasnt that and i change my booster and combination valve and sitll the same i have bled the calipers all and the master cylinder but a a just don khow wath alse cuold by du u have any sugestions

corbett_auto · 03-19-2009, 01:54 PM

How fast does it go to the floor? Imediately or slowly

If you pump the pedal does it get firmer? do not pump it too fast, but can you build it up any?

Have you checked the system for any leaks?

Keep us posted on oyur problem.

elg4llo · 03-21-2009, 01:50 PM

hi corbet thanks for aswwer ye the pedal go inmediatli to the floor after a have crank the car and yep a have check for leaks and no i have found no leaks and yes if i pupm on the pedal it semms to work i litle but if i stop punp it like one min. i loose all presure what it u thing i have chanche mi master cylider 2 times and now i thinking on changing the abs pump bt its very expesive

corbett_auto · 03-21-2009, 03:03 PM

The ABS system is an independent part of the brakes. If it goes out, it will not affect the normal function of the brakes. So do not spend the money or time on ABS parts.

Honestly it sounds like you air in the system. Are you sure bleed the brakes correctly? Did you bleed the master cylinder before you installed it? Also if you have rear drums and you are bleeding the brakes by pumping the pedal..... insure that the rear brake shoes are adjusted properly before you go through the bleed process. Trust me it can effect the outcome.

My recommendation is that you take your time and re-bleed the entire system. Starting with the master cylinder.

Satty101 · 03-21-2009, 05:35 PM

Your problem definetly sounds like air in the line.

http://www.brakebleeder.com/product.php?pid=37

I highly suggest one of these. It's the best tool I've put in my toolbox that's brake related. It goes on the bleeder screw on your caliper/cylinder and bleeds them the best way. Goes through the caliper and forces air to the master cylinder, the way it wants to go. Plus you don't have to bother having someone hitting the brake while you do it.

elg4llo · 03-22-2009, 02:01 AM

ok i have now put everiting togeter after takin the master cylinder for the 3 time i have bleed everiting caliper no have no air bubles.master cylider bleed it and still have same problem i have change the master cylinder 2 times but i have herd the they can by bad some times i now people the said they have change it tree or four time before they get a good one i buy it from advance autoparts and a think its a rebuild one shold i traid it again

corbett_auto · 03-22-2009, 03:59 AM

Your statements sound like you bled the calipers first, then the master cylinder. Have you bled everything in the right order? Yes occasionally parts can be bad, but master cylinders usually are ok. The things that you may need to go through 3-4 on are things like carburetors, starters and alternators.... If you truly think the master is bad, just buy a new one.

But again I strongly believe that you are not bleeding the system correctly. Before you spend any ore money go through the whole system step by step and insure you didn't miss something.

Because this is not something I typically do everyday (My specialty lies in metal work, bodywork and electronics) will some one walk him through this step by step? So I do not miss something.

elg4llo · 03-22-2009, 06:14 AM

ok bleed the master cylinder i put some plastic scru s with holes atach a litle piez i hose o 2 and put the end of hoses on the resevoir tank then pump till i dont stee no more bubles and then i put the master cylinder in but every time i put it in wen i lose the plastic plugs to install the line i lose fluid so bleed tha connecion by pressing the brake pedal all the way old it in and tide the line no bubles then i move to the calipers on the rear hook i hose to the bleeder screu sumerge the end of that hose on a glass with brake fluid lose the screu pump the pedal till i see no more bubles coming out , then i apply the same proses to the rest of tcalipers