Any tips on flushing the C5's cooling system?
Thread Starter
Le Mans Master
Joined: May 2000
Posts: 5,267
Likes: 15
From: Syracuse NY
Cruise-In II Veteran
Any tips on flushing the C5's cooling system?
Hey:
I am going to be flushing the cooling system in my C5, as the Dex is now coming up on 5 years... Everything looks clean, so I plan on running tap water thru to clear out the old, and then add Dex to get the 50% mix.
Anyone with experience who can offer some time saving / trouble prevention tips, please chime in
.
Thanks in advance!
I am going to be flushing the cooling system in my C5, as the Dex is now coming up on 5 years... Everything looks clean, so I plan on running tap water thru to clear out the old, and then add Dex to get the 50% mix.
Anyone with experience who can offer some time saving / trouble prevention tips, please chime in
.Thanks in advance!
Burning Brakes
Joined: Aug 2000
Posts: 1,132
Likes: 1
From: Morganton, NC, USA
I've previously posted a procedure I developed for my C5, but I haven't received much positive feedback. I think the owner's manual says the C5 cooling capacity is about 12.5 quarts. When you open up the petcock under the radiator, you only get about half of this amount out. Therefore, there's still about 6-7 quarts in the block, H2O pump, heater core, or wherever. There's supposed to be drain plugs on each side of the block, but I don't think they are very accessable or practical, so what I do is force water through the coolant system to purge out all the old coolant. To do this, I bought 8" of 2"dia. radiator hose that I hose clamp to the inlet on top of the recovery tank. With PVC fittings, I made a hose adapter to clamp to the other end. I then run city water through the coolant system until the discharge from the radiator starts to run clear. I then close the petcock and turn on the engine until it reaches operating temperature with the heater running. I then open the radiator drain and run for another 5 minutes. This appears to purge all the old coolant out of the system. Let me know if you want to know what to do next.
Race Director
Joined: Sep 2004
Posts: 17,786
Likes: 4
From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Originally Posted by FKING1
Taking mine to a Dealer where they hook the system up to a machine and power flush it with some solution.
Fred
Fred
I did that, it changes 100% of the fluid. Less time and less mess.
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
Be careful opening the radiator drain plug, it only turns 90 degrees. You can break it if you turn it too far, it does pull out.
The shop manual says you don't have to flush the system if it is clean. My 1998 was clean in 2003, so I just refilled. You must top it off 3 times, reving engine to 3,000 rpms to get all air out of it. Mine drained almost all (12 quarts) out of system. I left car down (off jack) so that it was level when draining.
Use distilled water for mixing.
The shop manual says you don't have to flush the system if it is clean. My 1998 was clean in 2003, so I just refilled. You must top it off 3 times, reving engine to 3,000 rpms to get all air out of it. Mine drained almost all (12 quarts) out of system. I left car down (off jack) so that it was level when draining.
Use distilled water for mixing.
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Melting Slicks
Joined: May 2003
Posts: 2,840
Likes: 301
From: Bonita CA
I guess it depends on how good your tap water is but it would be terrible to ever mix any tap water in a cooling system here. Too many minerals in the water. I would use only distilled water, even just to flush. NEVER any tap water!
Instructor
Joined: Aug 2005
Posts: 120
Likes: 0
From: New Baltimore Michigan
The old way of flushing out the old engine anti-freez with a garden hose going down the driveway and into the local sewer is a no-no in my state 
.
Therefore, flushing out your engine is no longer praticle for most backyard mechanics unless their is a holding tank involved, and taking the used fluids to a recylcle/reclame center just like used oil. Getting ticketed for this stunt is extreamly costly
. Better to take your auto to someone who has the equipment and knowhow. I would think that most states have these dumping codes.
. Therefore, flushing out your engine is no longer praticle for most backyard mechanics unless their is a holding tank involved, and taking the used fluids to a recylcle/reclame center just like used oil. Getting ticketed for this stunt is extreamly costly
. Better to take your auto to someone who has the equipment and knowhow. I would think that most states have these dumping codes.
Burning Brakes
Joined: Feb 2004
Posts: 1,024
Likes: 108
From: Ocala, Fl. State of Confusion
The problem with letting a shop do it is that they don't refill with distilled water. I even left 2 gallons of distilled water for a garage to mix in another car of mine. They forgot and put in tap water.
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
Originally Posted by BananaVett
The old way of flushing out the old engine anti-freez with a garden hose going down the driveway and into the local sewer is a no-no in my state .
Therefore, flushing out your engine is no longer praticle for most backyard mechanics unless their is a holding tank involved, and taking the used fluids to a recylcle/reclame center just like used oil. Getting ticketed for this stunt is extreamly costly . Better to take your auto to someone who has the equipment and knowhow. I would think that most states have these dumping codes.
. Therefore, flushing out your engine is no longer praticle for most backyard mechanics unless their is a holding tank involved, and taking the used fluids to a recylcle/reclame center just like used oil. Getting ticketed for this stunt is extreamly costly
. Better to take your auto to someone who has the equipment and knowhow. I would think that most states have these dumping codes.I always prefer working on my own car, I know what I do is right.
