Leak under dashboard - 2007 Nissan Frontier SE Crew Cab

If it smells like coolant it could be the heater matrix under the dashboard leaking. Your probably better to get a mechanic to deal with it as you will have to strip the entire dashboard off to get to it.

I did not understand your question. Is it about your heater matrix and is leaking? or is it anything else having problem under your dashboard? If it is about your heater matrix,the only thing you must do is just to take it to a specialist auto electrician to do the renewal as it is very difficult for you to do it and even you do attempt,the only thing you will manage is either to brake something valuable,and cost you might double paying.
My professional advise please ask for an expert.
good luck.

The problem has nothing to do with a "vacuum pump."

You either have a vacuum leak under the dashboard (vacuum line broken or fallen off), or you have a bad vacuum solenoid (less likely).

Best thing to do is listen for a hissing sound under your dashboard when the vehicle is running with the A/C off. Find were the hissing sound is, and there's your vacuum leak!

(My bet is that you will find the vacuum line has come off of the automatic parking brake release. This is the most common source of internal vacuum leak in those vehicles.)

Well your car is 113 years old it's bound to leak somewhere, I didn't know they made sunbirds in 1900

could be antifreeze ,have a taste and if its sweet then it is most likely antifreeze ,if directly under the pedals then it could be brake fluid thses are the only two things that would leak under the dash on this vehicle that i can think of offhand

May have to check out if the vacuum motors have the vacuum tubes attached but this may take a lot of work to disassemble the heating ventilation air conditioning out of the dash and underneath the dashboard. If rain enters the compartment under the dashboard, the pan that is designed to catch water may be disturbed or cracked somehow. Try to check fuses for a/c and the heating, the cruise control, and windshield wipers to see if there is an obvious electrical issue there. The vacuum leak is not related to the windshield wiper motor not working.

Good luck on this repair.

test the heater core

The leak is the evaporator which is in the dash.The complete dash has to come out to remove the hvac plenum to remove the evaporator.It is about a 7 to 10 hour job.The factory evap.core is about $475 and what ever the labor rate is for the repair shop.Hope this helps.Good luck.

HI. This will be the cause of a failed heater core device. The heater core has ruptured, thus causing the coolant that flows through this device to leak out onto the cabin floor. The core is mounted under the dashboard, on the passenger side. Inspect the hoses that connect to the core. If they are not loose, and the clips are tight, the core may be damaged.

The core must be replaced if it is , indeed, damaged.

Where is the leak?
Passenger side under dashboard area? (heater core)?
Near front of car? (Radiator leak)
Under fanbelts and pulleys? (water pump)
Under middle of engine (water hose)

Please .. more info.