Failing brake booster / master cylinder?

[cout]

Here are the symptoms I've recently started seeing:

* Idle at 1500 rpm, usually will go down to 1000 rpm _after_ I come to a complete stop, but sometimes stays up at 1500 even then.
* Suspected vacuum leak but haven't been able to detect one. Replaced PCV with purolator supra valve and brand new hoses.
* Brake lights often fail to go off when the car is parked. I can get the lights to go off if I tap the brake pedal once or twice.
* Brakes occasionally feel mushy like there is air in the lines. Took it in to mechanic since I didn't have time and was told rear brakes needed to be adjusted (I had previously burned up the automatic tensioner cable in the passenger side rear brake due to the exhaust system putting pressure on the emergency brake). I do not know whether they did a bleed. They did not charge me.
* Windshield wiper motor seems to have failed. I would guess that this is unrelated but the motor is next to the booster, so maybe it is related?

If the problem were just the brakes I wouldn't suspect the booster, but since there appears to either be a vacuum leak or a problem with the AIS, I'm wondering whether the brake system is the cause of my leak. Can I verify just by closing off the vacuum line to the booster or is there a better way?

I was also hypothesizing that it could be a failed brake pedal sensor or that the pedal itself is sticking a bit, since according to http://minimopar.knizefamily.net/ecu/brake_sw.html the computer will raise the idle speed when the brakes are depressed (is this true for both manual and auto?).

[cordes]

The brake switch is right behind the brake pedal. It should be easy to test. If it is bad it just twists out and new ones are very plentiful at JYs on the cheap.

The wipers not working could be from a bad ground. Check the ground by touching the bracket for the motor with a good size jumper wire which you ahve hooked to ground.

[turbovanman²]

Booster is easy to check, turn off the car, you should have aprox 3-4 pumps of assist left, if no, then its leaking or the check valve is bad.

Bad MC will cause the pedal to go to the floor.

[tsiconquest88]

The wiper motor ground needs to be re-done. thats all most likely. I had the ever so common wiper issues, i sanded and put the ground back and it was fine for a long time- till this post apparently. You might want to just do a new ground altogether now.

Soft pedal is any leak in a line or a bad caliper, etc. Could be the rear wheel cylinders as i had not done anything to the rear brakes. Front pads i did new not long before i sold it to you. BTW im pm'n you cus i want to ask you something.