Luis Ramirez
TYF Newbie
- Joined
- Nov 22, 2016
- Posts
- 23
- Reaction score
- 2
Anyone familiar on how to drain the radiator and heater core on a 03 suburban 5.3V8 and where is the drain plug located ?? Anyhelp is appreciated thanks !
Radiator coolant change
- Thread starter Luis Ramirez
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
MrBalll
Full Access Member
If you're fortunate enough to have a drain plug, which I think the 03 did, it will be on the very bottom of the radiator on the drivers side slightly behind a wire loom. Very small black plastic pep ****. Unscrew it and drain.
OP
OP
Luis Ramirez
TYF Newbie
- Joined
- Nov 22, 2016
- Posts
- 23
- Reaction score
- 2
Alright thanks ! and yep I gotta look for it
4WDTRK
sleeps in garage
I just finished servicing the coolant within the last week. A tip given to me and I'll pass along is just to pull the lower radiator hose when draining. It's much easier, drains faster, and you'll get more old coolant out. I drained, filled with distilled, heat cycled, drained...repeated that about 4-5 times until the old coolant came out almost clear. Finally refilled with full strength dexcool. Keep in mind you will only get about half the system capacity out by draining just the radiator. Any other questions just ask!
OP
OP
Luis Ramirez
TYF Newbie
- Joined
- Nov 22, 2016
- Posts
- 23
- Reaction score
- 2
Alright thanks for the tip !!!
Just heard about this trick, makes like easier.
4WDTRK
sleeps in garage
Another tip...replace the factory hose clamp on the lower radiator hose with a regular stainless hose clamp. It will make removal and installation MUCH easier. I hate fiddling with those factory spring clamps!
grnphrog
TYF Newbie
- Joined
- Jul 16, 2016
- Posts
- 11
- Reaction score
- 3
Unbelievable! Spent 30 minutes trying to get that dang spring clamp off, and another 30 minutes trying to put it back on.
I read your tip about putting on the 'Stainless Steel' clamp... and went straight to the auto parts store to buy one... I've removed the hose 4 times since and each time it has taken me literally 5 minutes to remove the hose, drain, put it back on and refill.
Your a god sent!
those factory clamps can be opened and locked open just like they come when new, just have to do it just right, I think there is a tool made for those clamps also that pushes it just right and locks it open
SnowDrifter
Full Access Member
- Joined
- Sep 5, 2016
- Posts
- 2,439
- Reaction score
- 2,681
Cant remember if your hear has a drain or not
If it does, it'll be on the drivers side bottom of the radiator. There will be a hose coming off of it that has its own little spot it tucks into so you can drain it into a bucket
If you don't have that, then you need to pop off the lower rad hose. I'd suggest taking off your ac+serpentine belts for this. Contact with coolant will ruin them. If you're feeling so inclined, toss a baggie over the pulleys and AC compressor clutch. Just don't forget to put these back on before you next start the vehicle!
If you want to do a drain and fill as routine maintenance, just let everything empty into a container, toss it back together, and fill up. These cars are super easy to bleed coolant on. Just fill the reservoir, start it, top off reservoir. Rev a few times, then go take a dump while you wait for the thermostat to open. When the vehicle is at operating temp, rev a few more times, check level, and you're done.
If you're looking to get some old schmoo out, go to the store, grab 10-15 gallons of distilled water and some coolant /concentrate/. Depending on how much room you have under the vehicle, you'll also want either a way of measuring how much comes out when you drain it, or a refractometer for checking glycol concentrations. If you can't get access to this, some coolant test strips will suffice. The floater gauges are dog shit and I'd sooner rub the coolant between my fingers and gauge strength from how slippery it is than use one. Seriously, just don't bother. *
You'll want to drain your coolant from the lower rad hose just as in above. Then you can remove your reservoir, take it to the sink, and scrub off the death-cool residue. Plug up the holes with a glove and some rubber bands, fill it with drain-o, shake it up, then go back outside.
Remove the heater hose from the water pump, clamp off the line that goes to the reservoir, the take your garden hose and just flush the crap out of it from both directions. Do it a few times, chase it with distilled water and a funnel, then toss it back together. If you want to replace the heater core connectors as part of preventative maintenance, now would be a good time. Grab a fuel line disconnect set to do so
Now go back inside, grab your reservoir, clean the crap out of it - you don't want any of the draino stuff messing with the pH buffers in the coolant you're going to put in. Install it back in the vehicle, connect all your hoses, then fill it with your distilled water. Don't use tap crap for this. Dissolved minerals can attack different metals in the cooling system over time. Look into hot water heaters and how they overcome this if you want to see why its not wise to do the same for our vehicles.
Bleed/burp/rev/etc with the distilled water, let the engine get up to operating temp so the thermostat opens, then remove the lower rad hose and drain. How long you let the vehicle cool for is entirely up to you and how comfortable you are working around hot things.
Fill it up, do it again.
Fill it up, do it again, but this time; measure how much water comes out of the system. Reference with the coolant capacity of your vehicle and determine if you were able to remove enough water such that when you fill with coolant, you have an appropriate ratio. If you need more air space, grab a large hex driver and pull out the threaded freeze plug on the drivers side of the block. If you have a block heater, that's where it will be. If you want a block heater, that's where you will install it.
Now you can add coolant to your system such that you get your desired ethylene glycol/water mix. I personally go for between 60/40 and 66/33 glycol/water ratio. If you weren't able to gather and measure how much coolant came out, then check with test drops / refractometer. I like the prestone yellow universal long life stuff, but since you've removed all traces of the previous coolant, you can use literally anything you want now
Bleed the system, install a NEW pressure cap, go for a drive, and you're done. The pressure cap is a preventative measure. Cooling systems need to have pressure in them. And no, it's not just for the boiling point. Your water pump relies on that pressure so it doesn't cavitate at higher rpms.
*The floater systems rely on density and surface tension, both of which will change as a result of temperature. You might think it's a non issue, but when referenced with a refractometer they were found to be completely inaccurate. Unusable, even for a ballpark reference. If you want to watch things float around, get a lava lamp.
If it does, it'll be on the drivers side bottom of the radiator. There will be a hose coming off of it that has its own little spot it tucks into so you can drain it into a bucket
If you don't have that, then you need to pop off the lower rad hose. I'd suggest taking off your ac+serpentine belts for this. Contact with coolant will ruin them. If you're feeling so inclined, toss a baggie over the pulleys and AC compressor clutch. Just don't forget to put these back on before you next start the vehicle!
If you want to do a drain and fill as routine maintenance, just let everything empty into a container, toss it back together, and fill up. These cars are super easy to bleed coolant on. Just fill the reservoir, start it, top off reservoir. Rev a few times, then go take a dump while you wait for the thermostat to open. When the vehicle is at operating temp, rev a few more times, check level, and you're done.
If you're looking to get some old schmoo out, go to the store, grab 10-15 gallons of distilled water and some coolant /concentrate/. Depending on how much room you have under the vehicle, you'll also want either a way of measuring how much comes out when you drain it, or a refractometer for checking glycol concentrations. If you can't get access to this, some coolant test strips will suffice. The floater gauges are dog shit and I'd sooner rub the coolant between my fingers and gauge strength from how slippery it is than use one. Seriously, just don't bother. *
You'll want to drain your coolant from the lower rad hose just as in above. Then you can remove your reservoir, take it to the sink, and scrub off the death-cool residue. Plug up the holes with a glove and some rubber bands, fill it with drain-o, shake it up, then go back outside.
Remove the heater hose from the water pump, clamp off the line that goes to the reservoir, the take your garden hose and just flush the crap out of it from both directions. Do it a few times, chase it with distilled water and a funnel, then toss it back together. If you want to replace the heater core connectors as part of preventative maintenance, now would be a good time. Grab a fuel line disconnect set to do so
Now go back inside, grab your reservoir, clean the crap out of it - you don't want any of the draino stuff messing with the pH buffers in the coolant you're going to put in. Install it back in the vehicle, connect all your hoses, then fill it with your distilled water. Don't use tap crap for this. Dissolved minerals can attack different metals in the cooling system over time. Look into hot water heaters and how they overcome this if you want to see why its not wise to do the same for our vehicles.
Bleed/burp/rev/etc with the distilled water, let the engine get up to operating temp so the thermostat opens, then remove the lower rad hose and drain. How long you let the vehicle cool for is entirely up to you and how comfortable you are working around hot things.
Fill it up, do it again.
Fill it up, do it again, but this time; measure how much water comes out of the system. Reference with the coolant capacity of your vehicle and determine if you were able to remove enough water such that when you fill with coolant, you have an appropriate ratio. If you need more air space, grab a large hex driver and pull out the threaded freeze plug on the drivers side of the block. If you have a block heater, that's where it will be. If you want a block heater, that's where you will install it.
Now you can add coolant to your system such that you get your desired ethylene glycol/water mix. I personally go for between 60/40 and 66/33 glycol/water ratio. If you weren't able to gather and measure how much coolant came out, then check with test drops / refractometer. I like the prestone yellow universal long life stuff, but since you've removed all traces of the previous coolant, you can use literally anything you want now
Bleed the system, install a NEW pressure cap, go for a drive, and you're done. The pressure cap is a preventative measure. Cooling systems need to have pressure in them. And no, it's not just for the boiling point. Your water pump relies on that pressure so it doesn't cavitate at higher rpms.
*The floater systems rely on density and surface tension, both of which will change as a result of temperature. You might think it's a non issue, but when referenced with a refractometer they were found to be completely inaccurate. Unusable, even for a ballpark reference. If you want to watch things float around, get a lava lamp.
Last edited:
