Then you have a coolant leak. Do you ever check all your fluid levels or know how? Seriously if you don't say so, so we can help you, if you do, then go bleed the coolant system fill it properly and keep an eye on the level every morning for the next week.

 

Indeed don't be shy if you don't know say something. We are here to help in 99% of cases.

 

On my trip to Moab last month, I noticed I didn't have heat either. I'm certain the system needs to be bled, especially after I did the whole manifold and valley pan. I've tried following the RAVE for bleeding, but for some reason I cannot for the life of me get the air out. All my hoses collapse when it cools down, which I know is a sure sign air is in the system.
Things replaced recently:
Radiator, tank, cap, thermostat (2x), plastic tee valve (replaced with black iron trick).

 

Update on my "No Heat" issue.
I just ran my truck from stone cold to operating temperature.
The Heater Inlet Pipe is warm, like the rest of my coolant tubes.
The Heater Outlet Pipe is dead cold.
I suppose this indicates a blockage in the heater core

Is the next step to hook a garden hose up to the Heater Outlet Pipe, and disconnect the Heater Inlet Pipe and flush it backwards?

How do I get that hose water out of the matrix once the flush is complete?

 

do you have access to air?

 

Yes, i do have access to air... That makes sense... flush it, then force air through it to clear as much tap water out?

Is my method correct for trying to clear the blocked matrix?

 

cant hurt. you may want to crimp the hose every know and then to create a surge to help lossen any debris.

 

And not too much pressure, it only has less than 20 PSI normally. It is a delicate device, and highly valued by Land Rover, they build the truck around it. In other words, you don't want to change it. If you can get some flow in it, you can introduce radiator flush or white vinegar and let it sit to convert some of the crispy crud to more liquid sludge so it can move out with the flushing.

 

Guess who now has HEAT!!!

Attached a garden hose to the output tube, and a clear plastic tube to the inlet tube.
Ran the hose.. At first a tiny amount of coolant, then something that resembled something that would come out of a baby, then crystal clear water.

I let it run for a minute or two, then shut the hose off. I found this one the ground. It was soft and squishy. There was more on the ground.

I then blew the thing out with the air hose. Got a bunch of water out, and blew until mostly air was coming out.

Hooked everything back up as normal, started the truck, ran to operating temp with heater on. Both the inlet and output pipes were now hot, and the heater was again working.

Now I have to wait for it to cool, and attempt to bleed.

 

Here's what that calcium build up looks like inside a core. Imagine that some might still be in the heater core and the radiator (use commercial flush product). Think about what would happen if you dumped a big bottle of radiator sealer into this - the sealer finds all the internal crevices and starts blocking everything up. Old school guys ran a gallon of white vinegar in for a few days before flush out. Of course, they also had a winter and summer thermostat they swapped out, and changed coolant more frequently.

Thanks for the pix.