I just flushed my radiator recently and recommend you pull the thermostat prior. The tstat is on the passenger side front of the engine just in front of the engine mounted fuel filter. Just follow the upper rad hose, there will be a large pipe. To get to it you will need to remove the alternator, vacuum pump, and loosen the bracket for the filter (manual recommends keeping the bracket in place probably to prevent breaking the fuel lines but good luck getting to the other bolt). Once you have the pipe off carefully scrape the seating surfaces and vacuum out the block.So, where I'm at now, I need some random help on various bits I'm working on. In no particular order:
1. How to drain the front diff
2. Does anyone use CLR to clear out a radiator? And while I'm here, where's the thermostat everyone says I need to replace?
3. In my heater box, does my blend door look ok?
On the passenger side follow the block heater wire and look on the side of the block there will be a plug just behind it, should be a 9/16 if I recall. pull this to help drain that side. Driver side is in the same area, bit more of a pain to reach. I would then pull the plug on the back/bottom of radiator on passenger side. With both plugs and tstat out I put my garden hose in the radiator top and flushed for a good while until it was clear. Then I ran the truck for 30 minutes and I don't have any more sediment in the rad.
I am sure there are some flush products out there and yeah, maybe everyone recommends DI water but who has that much kicking around?
I used some teflon tape and some yellow rectorseal 5 (any ptfe paste will work) on the block plugs. No leaks 1,000 miles later!