I recently purchased a '98 Dakota and i am having brake issues. The pedal started to go soft so i replaced back shoes and front pads. I bled the fronts no problem and when i went to bleed the rear i am not getting any fluid to rear passenger side. I can not bleed the rear driver because the valve is broken. Pedal is soft and will go all the way to the floor eventually when pressed softly, if i push it hard and quick it seems to grab and hold ok. Curious if anybody thought it was a master cylinder or booster problem. Not a ton of experience with brakes and could really use any help anybody can give. Thanks in advance

 

Are you getting fluid out of the drivers side rear wheel cylinder?

Replace the passenger side wheel cylinder. They aren't very expensive at all.

Any air in the system will give you a sinking pedal because you're compressing air. You can't compress fluids.

It wouldn't be the booster. A sinking pedal is a hydraulic issue, not booster.

 

First I hear you

But how did you bleed the system there is an order to bleeding the brakes back to front and usually back passenger side first the front not that important but front passenger side first after the back are done.

Never let the master cylinder go dry as you do this or you will inject air into the system

Replacing a back cylinder is easy but can get a bit tricky if you have never done this before.

Cylinders are $10 to $25 depending were you get them

Hint take pictures as you go so you know how to put everything back together

This may be a good time to flush all old Dot 3 out of the system if never done before

One more thing I would do is visually check all your break lines for any leaks

 

So we couldn't get the back valve to break free so we bled the fronts while we waiting for the liquid wrench to work. Never got any fluid to the back passenger side. Looked like nothing was moving the resavoire level never changed. Very odd when depressing pedal quick and hard at higher speed it grabs good and holds. When depressing slowly pedal will go soft, had pedal drop all the way to floor and stay there today. All shoes are new, and front pads replaced. Not sure where to even start now. Any ideas?

Also did check and no leaks in lines anywhere.

 

Change the rear wheel cylinder if you can't bleed it. If there is air in the line it will do just what you're describing.

 

But im not getting any fluid to the rear passenger side at all. I should get some kind of fluid to the rear after attempting to bleed corect? Could it be a master cylinder or a booster problem? I do get a pretty load sqeaky noise from the pedal when i press and depress.

 

check to see if you have a leak as there is an isolation valve that will close off the rear or front brakes if it has a leak. its called the hydraulic system control valve it can be checked for operation by depressing the pedal with key on engine off losen a bleeder screw and the brake light should come on. you should pull your drums off and check wheel cylinders if there is no leak that valve maybe stuck

 

I get it now, I got the sides confused.

It could be the master cylinder. The booster has nothing to do with moving fluid, all it does is help you push the pedal.

Have you ever bench bled a master cylinder? You could rig up the same thing, while installed, and see if it moves fluid.

The valve Rycoma is referring to is called the combination valve. It distributes pressure to the rear brakes and has the brake warning switch on it. It could have failed but the pedal should be very hard if it did as fluid wouldn't be allowed to flow to the back brakes.

 

not really 00dakdan I had a 92 dak. brake light was on pedal was soft if I pressed it slowly down but hard if I slammed it turned out I had a blown out wheel cylinder the valve limits the fluid but does not completely shut it off

 

not really 00dakdan I had a 92 dak. brake light was on pedal was soft if I pressed it slowly down but hard if I slammed it turned out I had a blown out wheel cylinder the valve limits the fluid but does not completely shut it off