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GMC 1500, thermostat and radiator flush, new hoses

K

kherman

Golden Member
OK, I'm set with the thermostat and gasket. I also need to know if there are any other hoses other than the top tube going into the radiator. I want to replace all the hoses I can.

Should I run the engine with water as the coolant only to "clean the system from gunk"?

How much dex cool will I need for a total flush?
 
When I drain the radiator, how much fluid do I have to collect? I need to know how many containers i need to catch it all.
 
Plan on spending some time on the flush, you only get a % of the original coolant out, in the summer time, I usually flush the system several times and run it for a week or so between flushes (I use reverse osmosis water), and then replace the fluid with the long lasting coolant & distilled water.

There's a lower radiator hose to replace (and there's usually a spring in it to keep it from collapsing, don't forget to replace it), as well as 2 hoses to your heater core, minimum, if you grab a service manual, you should be able to identify all the coolant hoses pretty easily.
 
I've decided tday is top tube, new thermostat and gasket only. I'll use new fluid to replace what I took out. Total overhaul this summer maybe.
 
When you put that new thermostat in make sure you have it facing the right way or it won't work. also make sure it is seated properly or you will crack the housing. Look at the old one for proper orientation.
 
Flushing the cooling system with water does not accomplish too much except for flushing loose debris out of the cooling system.
The only real way of cleaning it is with a commercial chemical flush using the back flush method.
If you are going to do a good job next summer, just drain the coolant, do a quick flush with water (With the engine cold), drain it thoroughly and refill with a 50/50 mix of Ethylene Glycol and water.
When replacing hoses, it is always wise to replace them all at one time, chances are that if one hose is bad (Soft, bulged), then the others are not too far behind.When removing hoses, it is best to grab a large set of channel locks, grab the end of the hose and twist it, this will break the bond between the hose and the fitting making removal easier.
Make sure that the thermostat goes into the housing the correct way, there is a wax pellet with a spring surrounding it, this end goes toward the engine, do not use silicone sealant on the gasket, either put it together dry or use Indian Head gasket cement.
 
Originally posted by: Curly
When you put that new thermostat in make sure you have it facing the right way or it won't work. also make sure it is seated properly or you will crack the housing. Look at the old one for proper orientation.
Click to expand...

I have the haynes manual at home (at work now). I'm not worred much about thenuts and bolts ofthe maintenance as I m worried about the fluids spilling. It's 40 degrees out which sucks though. I can't live wihout a heater in my truck any longer :|
 
If you just want to do the thermosat, darin about 3 cup fulls from the drain cock on the bottom of the radiator, this will drop the level of the coolant below the thermostat housing.
 
Originally posted by: Roger
If you just want to do the thermosat, darin about 3 cup fulls from the drain cock on the bottom of the radiator, this will drop the level of the coolant below the thermostat housing.
Click to expand...

3 cups is all! Phew, that's not much at all 🙂 Piece of cake. Autozone will take old dex cool coolant and recycle it, won't they?
 
Yes they will, DO NOT mix DexCool with normal Antifreeze, they are incompatable.
 
There is an upper and lower radiator hose. Most cars have several other small hoses going to various sensors and heater hoses. They should all be replaced!

I always get my radiator flushed and antifreeze changed at the local shop. They pressure test the system as well as flush the radiator using a machine that exerts considerable pressure and gets ALL the crap out of the cooling system. They also properly dispose [recycle] the antifreeze. You cannot be too careful with the cooling system. Overheating is THE primary reason many cars get junked way before they would've worn out if they had received routine maintenance.
 
Come to think of it, I had the system "cleaned" about a year ago. Back when I *shutter* paid for someone to do oil changes. Time to go through receipts.

I'll do the top tube since I have to get the thermostat out anyways and that tube will have to be empty 🙂

This summer, I'll probably do an overhaul ofthe engine. It's almost at 100K miles.
 
If you catch the anti-freeze in a clean container, you can put it right back. For your job, that would be the best thing to do.
Drain out about a gallon to be sure, and set it aside where you will not knock dirt off the engine into it, etc.
all this is dependant on having good antifreeze in there in the first place, which is probably the case, considering you paid to have it flushed a year ago.
 
Originally posted by: skyking
If you catch the anti-freeze in a clean container, you can put it right back. For your job, that would be the best thing to do.
Drain out about a gallon to be sure, and set it aside where you will not knock dirt off the engine into it, etc.
all this is dependant on having good antifreeze in there in the first place, which is probably the case, considering you paid to have it flushed a year ago.
Click to expand...

Tis very true. I have a gallon milk container I plan on rinsing out and using. I need a tube to do that. though. I'll use a funnel to "catch" it as it falls.
 
If you drain out a gallon, you will have to purge the cooling system before driving the vehicle, if you drain only a few cup fulls, you will not need to.
 
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