I just looked under the hood because im going to the junkyard tomorrow to try and find some replacement interior pieces and a new overflow coolant box (the clips are broken so it's currently zip-tied to my truck) and I found myself topping off all my fluids. When I checked the radiator I noticed that my fluid was once again the color of rust. But this time its starting to form kind of a plaque like substance that is close to clogging up right where the cap is. So i figured that its time for another radiator flush. Im curious though if when flushing the radiator do you have to disconnect both of the tubes flowing to the engine? or do i only have to remove the radiator plug? all previous times when I flushed my radiator i have removed the hoses. I feel like if i remove those hoses there is no way to flush out the bad (old) radiator fluid inside the engine. so when i fill the radiator back up it just mixes with the old crap stuff again, not accomplishing much. I NEVER have problems with overheating by the way. Even when pulling my trailer all day in the Texas heat. Any pointers?

 

When i do mine i drain what i can out the radiator then i take the lower hose off and bend it down so whats in the engine will drain out some then i put everything back fill with water get it warmed up then drain it the same way again and i do that several times till the water i drain is pretty clear so usualy 3 or 4 times i do it then put your mix in and all good.

 

There's a flush kit, costs like $5, and you hook the garden hose to your truck and run it until it's clear.

 

If the crust is forming that bad where you can see it then imagine where you can't. I'd be pulling the thermostat out and replacing it. And back flush the engine while its out.

 

My temperature gauge on my cluster has always ran far left on the cold side. except for ONCE when i overheated my engine trying to get out of a ditch. i think you are right... i think i need to replace the thermostat and while im at it im going to replace all my hoses because they are showing signs of rot. Im just really afraid that ive got rust in my engine...

 

Replace the temp sending unit also. Its cheap and I bet its reading wrong.

 

But what im trying to find out if it is ok to flush the system with the two hoses still connected to the engine. or is it Vital to disconnect them.

 

I will be replacing both of them sunday or monday followed by a very thourough coolant flush and ill let you know the results. Im led to believe the thermostat is stuck open, because only one of my heater hoses are actually heating up, the other remains cool.