Coolant Flush

Looking for a good technique to drain the coolant out of my 454s and flush the system. Drain plugs are completely inaccessible. Would like to remove coolant without filling the bilge or running afoul with the EPA. Is there a way to capture all the old coolant ?

Can you suck it out, as one does with an oil change?

Jeff

Do have a vacuum tank but don't think there is a place to insert the tube low enough to suck out most of the fluid. I think I can get some through the fresh water pump bypass. Thinking about opening the connection at the thermostat and hosing in fresh water and forcing out old coolant into a bucket at the same time. The optimum solution still seems elusive.

Its gonna be messy...best thing is to contain it and recover as much as possible.

You can get most out by pulling to hose from the HX to the circulating pump but there will still be some in the block - that's why the block drain plugs are there....also, best to drain the manifolds if it is a full FWC system (90%+ are).

Finally, best to use the full strength stuff - there will be some residual water - and adjust the concentration for the local climate....

Managed to flush the entire system without getting any AF in the bilge. Disconnected the water pump bypass at the filler neck, attached the suck-o-matic tank to the end of the hose and was able to pull five quarts. This effectively drained the top side hoses. Disconnected the system at the T-stat housing, removed the T-stat and collar hose. Using PVC tube and rubber couplings (with provided hose clamps) from Home Depot, directed fresh water directly to the HX while draining coolant from the T-stat housing in to five-gallon buckets. When the drained water was clear, inserted a new T-stat and reconnected the system. Sucked out another five quarts of water and added new AF. I'll check in the fall if more AF is needed to survive the Florida winter.

re: Florida "winter".... actually a mixture of 50/50 anti freeze and water is more effective transferring heat than straight water or 100% antifreeze... so your engine will cool more efficiently, i.e., respond to transient changes in heat load, with a 50/50 mixture.

Bob brings up a good point - being down south, you could probably go towards the minimum concentration of antifreeze (going on memory, its ~ 30%) recommended in the manual....the concern there isn't so much the freeze point but the anti-corrosion properties of the coolant...alkalinity being one of the more important ones....

Re: Coolant Flush
A mechanic at our marina just told me to:
Run one engine to temperature. Then disconnect the coolant lines running into the Water Heater and put the "return hose" in a 5 gal bucket of new pre-mixed antifreeze (coolant) and the other (inlet) in an empty bucket. Start the engine and let the coolant exchange happen.
This method seems almost too simple. Only one of my engines is connected to the heater so the other would require some temporary plumbing, but that may not be too bad.
Anyone see a problem with this????

I don't do it that way....biggest issue is dilution....lots of others as well.

Bottom line is, for routine maintenance, rarely do you find a 'better' way than what the factory service literature provides.

Not sure, but introducing cold water into a warmed up engine may be an issue.

I also want to drain the coolant now and am facing the same problem. How did you solve this problem in the end? My sensor on the car showed the engine overheating, although this should not have been. I read here https://thetoolscout.com/best-refrigerant-leak-detector/ about a tool that can detect a coolant leak and I found a leak in my radiator. My uncle said that I was lucky that I immediately identified the problem because if I haven't caught on time, it would have led to bad consequences. I try to drain the liquid myself, but it does not work, I can not contact the service now due to lack of money, is it possible to somehow handle this myself?

I use a shop vac. I disconnect the hose at the bottom of the manifold and stick the shop vac hose in it. Still get some AF in the bilge, but suck it out with vac.