Partial Coolant Changes?
Thread Starter
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
Partial Coolant Changes?
The threads asking about radiator flushes and coolant changes brought to mind my last flush & change. It's a messy job and spreads toxic chemicals all over the driveway. Does anyone follow a schedule of siphoning out a gallon or two of used coolant and replacing just that volume with new on a regular basis? Wouldn't be a mess (though everything I tend to do turns into one) and I'd be cycling in new chemicals and diluting the mineralized water that was trapped in the system during the last full flush.
A 327/350 has a coolant capacity of ~16 quarts; a 427/454 holds ~23 quarts. By pulling out 4 quarts a year, you're essentially changing out the full system every 4-5 years.
What do you think? Pitfalls?
A 327/350 has a coolant capacity of ~16 quarts; a 427/454 holds ~23 quarts. By pulling out 4 quarts a year, you're essentially changing out the full system every 4-5 years.
What do you think? Pitfalls?
Burning Brakes
Joined: Jan 2022
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I'm a fan of this idea, been doing it for decades and never a problem with corrosion, plugged systems or mismatched coolant types. I use Peak universal antifreeze and distilled water. Our corvettes are relatively easy to get to the block drain plugs, some cars are extremely difficult. Do a partial change every couple of years and you are good to go with any make. Buy PH strips to test the coolant for proper corrosion resistance if it gives you peace of mind, mine always tested as like new so I stopped.
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I always use anti-seize on the upper & lower radiator hoses so it's easy to pull the end of the lower hose off the radiator or the engine...or just remove the clamp and ease a screwdriver between the hose and the connection to control-drain the fluid into a 5 gal. bucket.
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I think my Bucket is slightly smaller. But can be slid under the car with the wheels turned hard right. Just fits under the radiator drain with the car on the ground. I open the drain in the evening. Let it sit overnight. Just about completely fills the bucket. But can be carefully slid back out.
Not saying I don't get a few drops or splashes but nothing difficult to clean up.
Not saying I don't get a few drops or splashes but nothing difficult to clean up.
Instructor
Joined: Nov 2020
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From: Brentwood, Tennessee
partial coolant change
The threads asking about radiator flushes and coolant changes brought to mind my last flush & change. It's a messy job and spreads toxic chemicals all over the driveway. Does anyone follow a schedule of siphoning out a gallon or two of used coolant and replacing just that volume with new on a regular basis? Wouldn't be a mess (though everything I tend to do turns into one) and I'd be cycling in new chemicals and diluting the mineralized water that was trapped in the system during the last full flush.
A 327/350 has a coolant capacity of ~16 quarts; a 427/454 holds ~23 quarts. By pulling out 4 quarts a year, you're essentially changing out the full system every 4-5 years.
What do you think? Pitfalls?
A 327/350 has a coolant capacity of ~16 quarts; a 427/454 holds ~23 quarts. By pulling out 4 quarts a year, you're essentially changing out the full system every 4-5 years.
What do you think? Pitfalls?
Instructor
Joined: Nov 2020
Posts: 126
Likes: 37
From: Brentwood, Tennessee
partial coolant change
[QUOTE=Prysmian46;1606492641]I do a partial change every year with a fresh 50/50 mix with distilled water and green Prestone in my 82 CE and 93 40th.[/QUOTE
In addition to my last post I personnally never remove the block drain plugs. I use a siphon hose to remove old coolant from the radiator and reservoir. When doing this every year there is generally no crud build up in the block.
In addition to my last post I personnally never remove the block drain plugs. I use a siphon hose to remove old coolant from the radiator and reservoir. When doing this every year there is generally no crud build up in the block.
Burning Brakes
Joined: Dec 2021
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[QUOTE=Prysmian46;1606492739]
for choice of anti freeze I have always used the zerex G05 great stuff
I do a partial change every year with a fresh 50/50 mix with distilled water and green Prestone in my 82 CE and 93 40th.[/QUOTE
In addition to my last post I personnally never remove the block drain plugs. I use a siphon hose to remove old coolant from the radiator and reservoir. When doing this every year there is generally no crud build up in the block.
In addition to my last post I personnally never remove the block drain plugs. I use a siphon hose to remove old coolant from the radiator and reservoir. When doing this every year there is generally no crud build up in the block.
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From: Virginia
Thread Starter
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
I think you kinda missed the main objection and that's purposefully flooding antifreeze all over the driveway. If I siphon a gallon out of the radiator with a simple hose on a yearly basis, there's no mess to replacing a quarter to fifth of the volume. Done regularly it keeps the antifreeze fresh and all of the good juju in there juju-ing without the mess.
Race Director
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From: Virginia
I think you kinda missed the main objection and that's purposefully flooding antifreeze all over the driveway. If I siphon a gallon out of the radiator with a simple hose on a yearly basis, there's no mess to replacing a quarter to fifth of the volume. Done regularly it keeps the antifreeze fresh and all of the good juju in there juju-ing without the mess.
Along with the juju, you can find a big jug, or a Homer bucket.
Team Owner
Joined: Mar 2002
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From: Huntsville AL
While antifreeze does degrade as it is being used (key word) the general rule of thumb is a "drain & flush" every 30,000, 50,000, 100,000 miles depending on the manufacture recommended maintenance. GM says for a 1973 Corvette the interval is every two years or 24,000 miles whichever occurs first. Now having said that I think GM was basing that on the car being driven daily.
Given the low miles we put on these vintage cars doing a drain & flush is pointless for the most part other than to set a baseline. If someone is overly concerned about the degradation of the corrosion properties of the antifreeze a radiator drain and refill should be more than sufficient to maintain those properties.
So, to answer the OP question I would have no issue with draining a gallon out of the radiator and replacing with new every year and call it a day.
Given the low miles we put on these vintage cars doing a drain & flush is pointless for the most part other than to set a baseline. If someone is overly concerned about the degradation of the corrosion properties of the antifreeze a radiator drain and refill should be more than sufficient to maintain those properties.
So, to answer the OP question I would have no issue with draining a gallon out of the radiator and replacing with new every year and call it a day.
Burning Brakes
Joined: Jan 2022
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Having pressure washed more than a couple of bare engine blocks with freeze plugs removed on engine stands, no way draining the block by removing the drain plugs is going to remove much from an all to common poorly maintained old cooling system. Most of the chunks, even if they were loose, wouldn't fit out of the drain plug holes.
If we're talking garden hose flushing, no way is that going to remove much beyond the point of the hose connection. It would be like dumping a bag of gravel in your bath tub and trying to remove it by overflowing the bath tub. But yeah, a bad idea leaving whatever mineral content is coming out of your garden hose in the engine block or anywhere else water can't drain out.
You have to keep the sediments from forming in the first place. Effective anti freeze and no introduced minerals.
If we're talking garden hose flushing, no way is that going to remove much beyond the point of the hose connection. It would be like dumping a bag of gravel in your bath tub and trying to remove it by overflowing the bath tub. But yeah, a bad idea leaving whatever mineral content is coming out of your garden hose in the engine block or anywhere else water can't drain out.
You have to keep the sediments from forming in the first place. Effective anti freeze and no introduced minerals.
Instructor
Joined: Nov 2022
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From: North Coast
I think that method would be ‘ok’ if it was fresh engine/cooling system.
Down on the farm we use industrial vinegar, as opposed to them nasty engine flush chemicals, we use a 1;4 mix of industrial vinegar/distilled water, run her a while, crack all the drains and view output.
usually takes 2 or 3 rounds of this to get clean flow, you’d be surprised at what comes out.
beware that stuff is brutal on the skin and you want to ‘rinse’ it a time or two with distilled water before refilling with antifreeze but boy oh boy does it work.
The vinegar comes in 5-20% mixture, I use the 20%.
It’s also very good for soaking old rusty/dirty parts but use thick rubber gloves..
Down on the farm we use industrial vinegar, as opposed to them nasty engine flush chemicals, we use a 1;4 mix of industrial vinegar/distilled water, run her a while, crack all the drains and view output.
usually takes 2 or 3 rounds of this to get clean flow, you’d be surprised at what comes out.
beware that stuff is brutal on the skin and you want to ‘rinse’ it a time or two with distilled water before refilling with antifreeze but boy oh boy does it work.
The vinegar comes in 5-20% mixture, I use the 20%.
It’s also very good for soaking old rusty/dirty parts but use thick rubber gloves..
Race Director
Joined: Mar 2017
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From: Virginia
I think that method would be ‘ok’ if it was fresh engine/cooling system.
Down on the farm we use industrial vinegar, as opposed to them nasty engine flush chemicals, we use a 1;4 mix of industrial vinegar/distilled water, run her a while, crack all the drains and view output.
usually takes 2 or 3 rounds of this to get clean flow, you’d be surprised at what comes out.
beware that stuff is brutal on the skin and you want to ‘rinse’ it a time or two with distilled water before refilling with antifreeze but boy oh boy does it work.
The vinegar comes in 5-20% mixture, I use the 20%.
It’s also very good for soaking old rusty/dirty parts but use thick rubber gloves..
Down on the farm we use industrial vinegar, as opposed to them nasty engine flush chemicals, we use a 1;4 mix of industrial vinegar/distilled water, run her a while, crack all the drains and view output.
usually takes 2 or 3 rounds of this to get clean flow, you’d be surprised at what comes out.
beware that stuff is brutal on the skin and you want to ‘rinse’ it a time or two with distilled water before refilling with antifreeze but boy oh boy does it work.
The vinegar comes in 5-20% mixture, I use the 20%.
It’s also very good for soaking old rusty/dirty parts but use thick rubber gloves..
How long is "run her a while"?
If you were swapping radiators anyway, and only wanted to clean the engine, could you connect the water neck to the water pump (bypassing the radiator), and run the engine for a few minutes, or turn the water pump with a drill or something? You could use a lot less vinegar and DI if you don't need to flush the radiator, too.
Instructor
Joined: Nov 2022
Posts: 158
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From: North Coast
We yank the thermostat n run em about an hour…never bypassed the radiator before so can’t speak to that.
unless it’s a fresh engine/cooling system there is crud built up in the block, once I cracked the block drain, nothing came out.
took a dental pick and worked it around the hole, lil chunks came out, then the floodgates of hell opened and literally pebble sized chunks came flowing out.
unless it’s a fresh engine/cooling system there is crud built up in the block, once I cracked the block drain, nothing came out.
took a dental pick and worked it around the hole, lil chunks came out, then the floodgates of hell opened and literally pebble sized chunks came flowing out.