Vacuum reservoir thanks for your reply this stuff i already suspescted I have checked all the lights i suspect the battery drain is comming from the light under the bonnet, maybe the microswitch is faulty. As for the vacuum reservoir could you please tell me how I check this and where it is located. Once again thank you for your assistance. Kind regards Kim Nelson [email protected]

You can but it will run bad. Might get check engine light to come on and it wont pass emissions.

Check alternator voltage output, might be low. obd2 scanner

Sound like the check valve in the vacuum reservoir has gone bad. The reservoir is located under the plastic cowl that is under the wipers. If the check valve has gone bad you have two options. 1. You can replace the vacuum reservoir. 2. You can pick up a check valve at your local parts store and install it in between the vacuum supply hose and the vacuum reservoir. Let me know if you have any questions and I'll do my best to answer them. Thank you for using FixYa.com!

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Look at your coolant reservoir tank does it look dirty inside it. If it does which I suspect your sensor near the bottom of the tank is what sends a signal to your coolant light. You can drain and clean the reservoir and sensor or the same but buying a new sensor if the same problem persists

Is the system ESOF ( Electronic Shift On the Fly ) or MSOF ( Mechanical Shift On the Fly ) ?

Lift and support the front of the truck so the front wheels are off the ground ( take safety precautions, chock wheels, jack stands, etc )
Key on, engage 4x4 and try to turn the front drive shaft.
If it turns it is a problem with the transfer case.
If it doesn't it is a front axle engagement problem.

I would suspect you will find the front drive shaft does not turn, and the issue is with the vacuum shift motor, the vacuum lines to it or the solenoids that operate it ( could be the vacuum reservoir, small chance ).

The vacuum disconnect motor is on the front axle, item #10 in the picture below :


Picture of it


The 2 vacuum lines to it change between 2WD and 4WD operation. You should have vacuum on the pink vacuum line when in 2WD mode and the light blue vacuum line when in 4WD operation.

If a test with a vacuum gauge does not show vacuum, chances are the vacuum line is cracked.
It is this simple.


If you do not have vacuum on either line, it could be the fuse to the solenoids is blown ( power is always at the solenoids, ground is operated by the GEM - Generic Electronics Module ) or it could be the vacuum reservoir behind the battery is cracked adn causing a vacuum leak.

Start with checking the fuse for the system, and verify if the front drive shaft engages and go from there.

Lift and support the front of the truck so the front wheels are off the ground ( take safety precautions, chock wheels, jack stands, etc )
Engine on, engage 4x4 and try to turn the front drive shaft.
If it turns it is a problem with the transfer case.
If it doesn't it is a front axle engagement problem.

IF the front dive shaft does not turn, check that the vacuum shift motor on the front axle is operating.


Item #10 in the diagram below.


The vacuum shift motor is vacuum operated ( name says that, I know ) the pink vacuum line is 2WD operation, the Light Blue vacuum line is 4WD operation.
If the motor does not move, you can check the vacuum lines to the vacuum solenoids on the firewall


The other is the vacuum reservoir behind the battery

You have a vacuum leak in the engine compartment mst likely. Check the vacuum line from the engine to the firewall and into the vehcile under the dash.
Also check the vacuum storage canister that stores vacuum for the heater controls when you step on the gas. You can just disconnect the hose to the reservoir and plug it temporarily to see if the system workd ok.

Vacuum Reservoir Removal and Installation

1. Remove the battery and battery tray. For additional information, refer to Section 414-01 .

1. Disconnect the vacuum hose and remove the vacuum reservoir.

1. To install, reverse the removal procedure.

IT SOUNDS LIKE YOUR VAC PUMP HAS FAILED IT SITS ON THE BACK OF THE ALT

The sensor is at the top of the rad next to the battery on the right side: easy to see but not so easy to reach. The sensor may not be defective, but dirty. If the coolant is dirty, it will coat the sensor and cause false readings. To check, unplug the sensor and check to see if the light goes out (allow 15 seconds or so). If it does, then remove and clean the copper probe of the sensor with a scratchy pad and reinstall. If the light comes back on, then replace the sensor. If the light stays off, flush your cooling system and replace with the green stuff: the pink Dexcool is evil.