Did A Complete Coolant Flush, Any Refill Recommendations?

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jomichael

jomichael

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91 3FE. Replaced the water pump, thermostat, many after market hoses that were on there with OEM, and replaced the radiator with a 3 core aluminum. I also flushed out all the lines and the heater core.

Are there any recommended procedures on refilling the coolant, like leaving the cap off to get the air out? Turn on heater? Also, is the Toyota coolant really that much better than Prestone or similar standard coolant? Don't care to spend double the money if the standard stuff will work fine.

Thanks for the advice.
 
SpenserAK

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Not a pro here, but with engine off, I fill slowly through upper rad hose until it stops taking any fluid, fill rad & reservoir, then run for a while, looking at scangauge to monitor true temp. I let it run for a while after reaching operating temp to make sure t-stat is open and fluid is moving, with heat on, occasionally briefly holding slightly higher rpm... takes a bit to really burp everything you can. I continually squeeze both upper & lower rad hoses to help purge. Once it seems like you can’t get any more into the rad, you can close it up and go on your way, but keep an eye on rad (when cool), reservoir & temp the next few drives and top off as needed. I usually don’t have to add much more. Never had symptoms of air in system when doing it this way.

I’ve seen people (non specific to 80s or Toyota) who stop burping when their dash gauge hits the middle, but that doesn’t mean you’ve actually reached operating temp & opened the t-stat, hence going by scangauge instead. In my case, my dash gauge hits its resting point at about 155-160, so you’re not quite there yet. It’s pretty much a dummy gauge.

If you’re changing colors from green to red or vice versa, it’s important to do thorough flushes to make sure all the old stuff is out first. This would include utilizing block drains

From my readings here, general consensus outside of diehard OEM-ers who swear by red seems to be that traditional is fine as long as there’s no mixing.
 
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jpoole

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Personally I prefer the generic green coolant from the local auto parts store. It's functionally equivalent to the red as far as I know and it's easier to get your hand on if/when you need to refill which could be especially relevant if you run low when traveling. Regular coolant changes are likely to help keep things cleaner long term than running any particular coolant (unless you go with specialty/no water coolant which is a different topic). I can't see any compelling reason to not just get the green and change it out every 2 years or so. If you want to splurge get bottles of 50/50 premix so that you don't have to mix your own.

My 80 has been really easy to bleed but it will keep taking coolant for the first few heat cycles until the bubbles have all worked out. Running up to temp with heaters on for the first fill could help you get things circulating fully and most of the air out with your initial attempt. Get enough coolant in to circulate before you start getting it hot and don't burn yourself messing with it after warm up :)
 
jomichael

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Not a pro here, but with engine off, I fill slowly through upper rad hose until it stops taking any fluid, fill rad & reservoir, then run for a while, looking at scangauge to monitor true temp. I let it run for a while after reaching operating temp to make sure t-stat is open and fluid is moving, with heat on.. takes a bit to really burp everything you can. I continually squeeze both upper & lower rad hoses to help purge. Once it seems like you can’t get any more into the rad, you can close it up and go on your way, but keep an eye on rad (when cool), reservoir & temp the next few drives and top off as needed. I usually don’t have to add much more. Never had symptoms of air in system when doing it this way.

I’ve seen people (non specific to 80s or Toyota) who stop burping when their dash gauge hits the middle, but that doesn’t mean you’ve actually reached operating temp & opened the t-stat, hence going by scangauge instead. In my case, my dash gauge hits its resting point at about 155-160, so you’re not quite there yet. It’s pretty much a dummy gauge.

If you’re changing colors from green to red or vice versa, it’s important to do thorough flushes to make sure all the old stuff is out first. This would include utilizing block drains

From my readings here, general consensus outside of diehard OEM-ers who swear by red seems to be that traditional is fine as long as there’s no mixing.
Thanks for the response. You leave the radiator cap off during this process, correct?
 
SpenserAK

SpenserAK

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Yessir. It won’t build up pressure as with the cap on, so no coolant explosions during the process.

I’m not running it after reaching operating temp for an hour or anything, just like to make sure fluid has a little time to flow before calling it good. As long as you get close, you should be good, and if your res system is working properly, remaining bubbles should purge themselves - just keep it topped off the next few days as needed
 
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FMC80

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I read when bleeding the rad after a flush, it's good technique to elevate the front end and run the heaters. When I did mine, I used ramps on an inclined driveway to point the front end way up. I let the engine idle for a long time while running the hot air in front and rear. I've done this procedure a few times and it seems to work.

Oh and I use Toyota Red...The green stuff is fine too if you don't care about your LC :rofl::flipoff2:
 
Marco Lau

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Fill the block with coolant/distilled water mix via the top radiator hose disconnected from the radiator till the block is full. connect the hose, continue to fill up the radiator via the cap while squeezing the top hose to remove air pockets while filling. drive the rig up on a ramp or on a wheel stop etc. to get the radiator as high as possible, keep the rig running with the cap off, turn on all heat and let it idle and warm up to temp. and occasionally blip the throttle to get the RPM up /water pump spinning to get all air pocket out. Works like a charm.... and don't forget to fill the overflow bottle to the full mark and monitor the level for the next couple weeks.
 
Feldrian

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In before the OMG YOU HAVE TO USE THE RED STUFF comments. :popcorn::popcorn:
 
FMC80

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Ha! I already started adding the green stuff, I'm trying to kill my 80!

I have to go buy more, the system holds a lot of coolant.
I can sense your HG disintegrating as I type this.
 
77mustard40

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Green should be fine in a 3FE, that's what I run in my 2F 40. I park mine in the drive where the front is elevated some and use a funnel that fits the rad opening perfectly. I over-fill it some so there's some in the funnel and run it from cold until it gets to full operating temp, heater on and monitor the funnel. It burps and belches along the way but usually stops once the thermostat opens. Then I cap it and fill the overflow to the line and call it good, I check the overflow for a couple of days just in case I need to add any.
 
jonheld

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Wow. So much drama to fill the cooling system. I never understood this.
After replacing the radiator, water pump, thermostat and the majority of hoses, I open the heater valve, Fill the radiator to the top of the filler neck and put the cap on. Fill the overflow bottle to the fill line.
The cooling system self bleeds, so this whole "burping" the system is really not needed. As air is purged from the system, the level in the overflow should decrease as more coolant is drawn into the system through the radiator cap as it cools down. After a few drive cycles, recheck levels and top off as required. Always fill the radiator to the top of the filler neck and the overflow bottle to the full line.
 
jpoole

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ha, @jonheld that's been my experience as well. I've been around a few vehicles that were not easy to bleed and required the purging etc. but my LC has been very forgiving and I've done full drains/flushes a number of times over the years. I have had air in the system after refilling but it always worked itself out quickly/easily.
 
peacesells63

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My 95 took 7 full flushes until the green was completely gone, along with the sludge from whoever didn’t flush it properly when they put green in. I put green back in it since I had 7 gallons of it on the shelf. Original head gasket and it’s had green in it for at least 12 years now. Don’t mix one with the other and you’ll be fine. I run red in my other 5 Toyota’s, since they have always had red in them..
 
jomichael

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I buttoned everything up last weekend and filled up the block only to find a drip at the water pump. What a pain. I have the pump out and a new pump to block gasket. does everyone use the gasket dry or do they add any gasket sealant? And what should the bolts be torqued to? It always seems to take me 2-3 times to get things right.
 
Bambusiero

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I can recommend using one of those special purpose radiator fill funnels - Filling, warming up, self purging of air - is very easy.
It allows you to overfill just a bit while things settle out, and easily pull off the excess without spilling much.
 
sogafarm

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I used to have a first year water cooled boxer engine in an '84 VW Vanagon. Two 10 ft. coolant lines running under the belly from the front radiator to the rear engine. Now that was a real pain in the arse to bleed the air, especially since they have the worst head gasket problems. The average head gasket lasts 100k miles in those engines with luck.

I need to change out a few hoses in the Landcruiser and will do a flush. Green is the current color and haven't had any troubles yet. I will probably go back with green just so I don't risk mixing the red and green coolants. I've read too many debates on coolant color to give a damn either way so will go the easier route and go back with green preston.
 
jomichael

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Finally got the refill done! Now just need to wait for the Texas summer to really test it out. Took a total of 7 gallons with an 8th gallon for topping off. I hope to never do that project again.
 
R

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Wow. So much drama to fill the cooling system. I never understood this.
After replacing the radiator, water pump, thermostat and the majority of hoses, I open the heater valve, Fill the radiator to the top of the filler neck and put the cap on. Fill the overflow bottle to the fill line.
The cooling system self bleeds, so this whole "burping" the system is really not needed. As air is purged from the system, the level in the overflow should decrease as more coolant is drawn into the system through the radiator cap as it cools down. After a few drive cycles, recheck levels and top off as required. Always fill the radiator to the top of the filler neck and the overflow bottle to the full line.
100%
 

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