My pickup (4.8L engine) is overdue for a coolant change. I've got 2 gallons of Dex-Cool antifreeze (not 50/50) and a bucket of distilled water that I've been saving from the dehumidifier.
I'm pretty sure there's a radiator drain petcock, but does that get enough coolant out of the engine block, or are there drain plugs, or do I remove the lower hose to finish draining the system?
I need to be able to get at least half of the old coolant out; planning to refill with water, run for a few minutes, drain again, repeat. Will probably temporarily remove the thermostat during all this. Then add
6.5 quarts of straight antifreeze, then top up with water. Unless I can figure out how to drain the block. Is that about right? Thanks.
Hey Bob All I've ever done is to look up the cooling system capacity.....then drain the radiator into a bucket (or siphon it)...see if you get at least half of the capacity in the bucket.... Then refill with good water and run and drain for a couple times . Then add pure antifreeze at half the capacity of system...then top off with good water. You can always use the reservoir to get that 50-50 mix.....you gotta clean it out too ! Never had any problems this way, but I have never used any chemical flushes either.... Good Luck..........Pete
That's what I've always done too, but I've never changed the coolant in a system with a pressurized surge tank before instead of an overflow tank. You can't really get in to the radiator -- maybe thru the upper radiator hose inlet, I'm not sure.
On my 99 Mustang GT with that kind of surge tank the only way to really get things flushed out is to pull the upper thermostat housing and put the new stuff in there.
This is the weirdest coolant system I've ever seen. I can't even find the thermostat; it must be built into the water pump.
I found the radiator drain. Everything I've read online says it's on the passenger side, but it's on the driver's side. I was able to drain
6 quarts out, very slowly, from the radiator and the surge tank. I doubt that I got anything out of the engine water jacket. The coolant capacity is 12.7 quarts, so I need to get another quart out if I'm going to fill-with-water, drain, fill-with-water, drain, fill-with straight antifreeze. I don't think the lower radiator hose will do it, but I can try.
My dad siphons 1 gallon of coolant out of his Suburban every year (older one with a real radiator with a cap) and replaces it with fresh 50/50. I think that might be a real good idea after this.
Nope, It is a bolt on part attached to the water pump. The water inlet/thermostat are a one piece unit.
Has the radiator been changed? It should be on the right side and drain out the bottom. If it's on the other side I would say that you either have a different radiator OR it's a running change vehicle.
Easy way on a surge tank system is to pull the upper surge tank hose. Then hook a separate line to the surge tank and run it to your drain tank. Then pump the new coolant mix in through the hose you pulled off. Faster and easier. For the DIY person who doesn't have the proper flush unit a simple drill powered pump will do the job. Just use straight water to flush out the system first. Then drive it some, it doesn't hurt if you reverse the heater hoses while you do this to help clean the core. Now use the pump to pump in the coolant. I usually go with a 60-70% blend with Dex-Cool. BUT if you do a full flush this way you do not HAVE to use Dex if you don't wish to.
I'm going to use Dex and distilled water. If I put the whole 2 gallons in and top up with water, that would be about 63%. I just might do that instead of having a quart left over.
The drain is definitely on the driver's side. A little petcock at the bottom of the radiator, with a 3/8" drain hose attached that runs up the side of the radiator and clips loosely at the top. It would have taken
*days* to drain out that hose; it acted like it was plugged up with a mud-dauber nest, but I pulled it off and checked it and it looked OK. So I unscrewed the petcock like a plug and caught the coolant with an old Cadillac radiator hose run into a bucket. Much faster.
I found the drain plug on the driver's side of the block. It's right by the oil filter. (the one on the passenger's side is probably hidden by the starter) It's about 1.5" brass plug with a 17mm (I think) hex socket. Amazingly, I had a wrench to fit it (I don't know why; something left over from working on Volkswagens 30 years ago.) Had to use an impact wrench to get it loose. Coolant went everywhere, but I caught another 2 quarts and probably lost almost as much.
I put the plug back in and only screwed it in about 2 turns, overfilled the system with distilled water, and and started it up and idled with the lights on, airconditioner on, and the heater on to flush the core. When the radiator hoses got hot, I shut it off and there it sits overnight. I'll drain it again tomorrow.
I like the idea of reversing the heater hoses to backflush the core. I didn't know you could do that.
The coolant still looked pretty enough to drink; like orange Nehi, no sludge at all. But it's starting to smell like fish after 8 years (only
50000 miles though.) I probably got lucky that it didn't gel up on me. Not gonna let it go that long again.
I forgot to mention, this is the original radiator, even tho' the drain is on the driver's side. If it was an mid-run engineering change, it was a good one because there's more room to work on that side.
I pulled the little drain hose off and checked it a little closer, and it had a spider in it. I blew it out, put back on and use it to drain the radiator, and it was still kind of slow but I got 2 gallons out this time in about 20 minutes, and it was still dripping. Not sure if it was slowly draining the block too (I doubt that because didn't remove the thermostat), or if I got more this time because I filled the surge tank to the top last night instead of just to the COLD line.
I pulled the drivers side drain plug again and drained that half of the block, put it back in and tightened it, now I'm about to fill it. (it's cold and rainy here today and I'm working outside, otherwise I'd probably fill-with-water/run/drain one more time.)
I'll put a golf tee in the end of that drain hose when I put everything back together to keep the bugs out.
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