Coolant flush machine
Thread Starter
7th Gear
Joined: Mar 2022
Posts: 7
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From: West bend, WI
Coolant flush machine
Considering going to my local mechanic and having the cooling system, on my 90 C4, done with the machine they have. Has anyone gone this route? Are there any pitfalls I should consider? I am not in a place where i can do a coolant flush myself, but i am pretty sure my car needs it.
Pro
Joined: Sep 2024
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Considering going to my local mechanic and having the cooling system, on my 90 C4, done with the machine they have. Has anyone gone this route? Are there any pitfalls I should consider? I am not in a place where i can do a coolant flush myself, but i am pretty sure my car needs it.
Safety Car
Joined: Mar 2017
Posts: 4,202
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From: LeClaire Iowa
I had one done on my new to me at the time (8 years ago) when I was still working and did not know how to do it properly. I am sure the skill of the operator has a lot to do with it. In my 96 GM put little pills in the cooling system at the factory (some kind of stop leak). I don't know if they did in 90. My machine flush actually made it worse. In my opinion it does not move enough water to clean the brown scum film off. This seemed especially true in the pressure reservoir tank and the lower block. A week after my machine flush I turkey basted out some coolant and took it to the shop to show them what it looked like. The response I got was that with older cars it sometimes took 5-6 flushes before it cleaned up. I was not happy but your milage may vary. Dan
Safety Car
Joined: Mar 2017
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From: LeClaire Iowa
After I learned I was not getting it really clean at a shop I figured out a way to flush it vigorously. See my post. Dan
Shop vac flush works! - CorvetteForum - Chevrolet Corvette Forum Discussion
Shop vac flush works! - CorvetteForum - Chevrolet Corvette Forum Discussion
Thread Starter
7th Gear
Joined: Mar 2022
Posts: 7
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From: West bend, WI
Thanks for the feedback. I think my first concern was does it create too much turbulance and cause other issues, but I think what I am seeing is all it really does is change out fluid. But probably churns up enough surface crude to make matters worse. So I may try the shop vac route.
Safety Car
Joined: Mar 2017
Posts: 4,202
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From: LeClaire Iowa
Thanks for the feedback. I think my first concern was does it create too much turbulance and cause other issues, but I think what I am seeing is all it really does is change out fluid. But probably churns up enough surface crude to make matters worse. So I may try the shop vac route.
Safety Car
Joined: Mar 2017
Posts: 4,202
Likes: 1,323
From: LeClaire Iowa
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Race Director
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From: Melbourne, FL
I don't believe in flushing any fluids in a car. Draina and fill. I would rather do a series of drain and fills to get all fresh fluids in than flushing personally. Especially for a fluid that's easy to service like coolant.
Melting Slicks
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After I learned I was not getting it really clean at a shop I figured out a way to flush it vigorously. See my post. Dan
Shop vac flush works! - CorvetteForum - Chevrolet Corvette Forum Discussion
Shop vac flush works! - CorvetteForum - Chevrolet Corvette Forum Discussion
I used Whaleman's procedure recently and although it tales some time I thought it worked well.
Melting Slicks
Joined: Dec 2009
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If you're afraid to flush or back flush a cooling system because it might cause leaks, then your parts are living on borrowed time. Plus, a garden hose gets nowhere near the 14 psi radiator operating pressure.
Race Director
Joined: Oct 2012
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From: Melbourne, FL
To your point, if the hose doesn't create as much pressure as the water pump, what's the benefit other than maybe time?
My tap water has 300ppm worth of crud in it, so I would definitely not use tap water for it personally.
Safety Car
Joined: Mar 2017
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From: LeClaire Iowa
It's more or just a general disbelief in the process in general. My 92 runs cool as can be, so I don't see a reason to try any sort of powered flushing, just keep the coolant clean.
To your point, if the hose doesn't create as much pressure as the water pump, what's the benefit other than maybe time?
My tap water has 300ppm worth of crud in it, so I would definitely not use tap water for it personally.
To your point, if the hose doesn't create as much pressure as the water pump, what's the benefit other than maybe time?
My tap water has 300ppm worth of crud in it, so I would definitely not use tap water for it personally.
Pro
Joined: Sep 2024
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I think people blow the tap water thing out of proportion. If you were so inclined, you could buy a cooling system pressure tester from Harbor Freight. Pump it over 15 PSI and check for leaks. If nothing at 20 psi and it holds for 15 minutes, your system is good.
Safety Car
Joined: Mar 2017
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From: LeClaire Iowa
I think the words "tap water" can vary widely from place to place. Dan