a couple days ago i turn on my car and try to put it into D. i step on the brakes but they wont go down even a little. maybe an inch but thats it. all 3 brake lights come on. could this be a problem with the pump or master cylinder?

 

lots of potential issues - you day the pedal won't move at all?

do the brakes work at all and it is just super stiff?

could be lots of things, but I would start by looking at the vacuum assist, and the hoses leading to the intake manifold....

 

well i cant tell if the brakes work at all but i cant move from P to D.
the resivor is full. i did unplug the battery and put it back on it was after this that they wouldnt work.

where is the vacuum assist?

 

First make sure your battery connections are tight and secure and on the correct terminals. When putting the terminals back on the battery did you plug positive or negative first?

 

yes to both

 

The brake is a mechanical device. I don't see touching the battery has anything to do with it. You can take out the battery and the brake still works. That's the safety design. I'd do like Mitsuguy. Also, check from the caliper all the way up, including the lines. Check if the brake pedal if it's stuck somewhere.

 

If happened after the battery was messed with so it should have something to do with it. I was just thinking maybe if you plugged the negative terminal first it caused a fuse to blow since you are supposed to plug the positive terminal first. Also, when removing terminals the negative should be removed first.

 

it makes absolutely no difference which one you plug in first, or un-plug for that matter... so long as they don't touch each other...

there is no fuse in the system that will have a negative effect on stiff brakes...

as was mentioned, brakes are 100% mechanical, the only electrically controlled item is the ABS pump, but you'd have to screw something up real bad to get it to lock in the closed position (it's a fail safe device)...

Anyways, again, it sounds like you lost your power assist.... do the brakes actually hold the car in place?

 

the only thing that will cause that is if your vaccume line is disconnected or if the valve is stuck i recommend changing the vaccume line /valve on the brake booster

 

I don't know guys, can it be that coincidental that after he connected his battery that the brakes stopped working? I mean it was working fine until he messed with the battery right?

I don't know if this link may help, but worth a shot I guess:
http://us.lexusownersclub.com/forums...0&#entry250189

 

Sorry, I was diagnosing for a hard brake pedal, not a stuck in park issue...

 

im confused now .is it stuck in park or is the brake not functioning?

 

The brake pedal can't be pressed down in order to shift the lever.

 

me too, someone posted a link regarding a stuck in park issue that was somehow related to the brake not being depressed...

thats why the question.... just making sure I read the first one correctly...

 

bingo the brake lights do come on