Radiator Cap/Excessive Pressure

You may try using the funnel to bleed any trapped air from the system

 

Is that done via attaching the funnel and giving both the upper/lower hoses some good squeezes?

 

Truck on jacks (or a lift)

Remove radiator cap

Open the lower radiator per cock, drain all coolant into a suitable container.

Close when done.

Insert funnel into radiator top. Start filling with Toyota SLLC (pink). Go slow. It'll bubble. Rinse and repeat until it stops filling and you've got a pool of coolant in there. Then start squeezing the upper hose. You'll feel bubbles and such move through it. Repeat until you feel no more. Make sure you still have a pool of coolant in the funnel.

Turn truck on.

Turn on all heaters to full.

Stand by the funnel. If the coolant level drops, continue to add more.

After about 10 ish min, the heaters should be blowing hot and your engine should have the proper amount of coolant.

Hope in truck, mash the gas to above 3000 rpm for a few seconds, let it down and shut it off.

If there is any coolant still in funnel (there should be) instead the stopper, transfer funnel to overflow tank, and let the rest into the tank.

Close all caps, spray any messes (coolant can be cleaned up with a drop or two of dish soap in a hand sprayer full of water)

Voila! Dont ever pay $180 for a shop to do that again.