Why is my radiator rusting after a Thermocure flush and fresh fill?

[Viking Jeeper]

Takes way too long plus on some, they want to burp a big bubble of coolant out right before the thermostat opens. If you pull the thermostat, you can fill, circulate, and drain in about 10-15 minute cycles. Gets a lot more work done in less time.

On that cycle are you draining the radiator and removing the thermostat housing to drain or is there more to it?

 

[LONGJP2]

Is it OK to run just clean water temporarily? I completely understand why we use coolant for colder temps but not sure of the ability of water to cool as efficiently as a 50/50 mix or how plain water will affect the metals.

IIRC, some antifreeze coolants have lubricants for the waterpump seal.

 

[SkylinesSuck]

It's fine to run regular water from the hose for short periods as part of the flushing process. It's not going to hurt seals or scale everything up in the short term.

 

[Rentmoney]

I know some of you are not going to like this LOL. I flushed my system using Cascade dishwasher powder, does not foam up or create bubbles. Heat engine completely then repeat. I did that several times during the day and finished by sticking a hose in the radiator and running into water was clear. My radiator looked like the above picture from the op. Everything in it now looks great has been 4,000 MI

 

[mrblaine]

On that cycle are you draining the radiator and removing the thermostat housing to drain or is there more to it?

Remove thermostat, reinstall thermostat housing, then fill, circulate, drain, fill, circulate, drain until the water is clear. With the thermostat in there, you have to run it until it comes up to temp and opens the thermostat to circulate the water to clean out the block.

 

[Blondie70]

I use the cheapest dishwashing soap I can find....clean water (from faucet) then a big ole shot of the soap....put cap back on and run a few days. Drain (will be nasty) do it again until happy. flush a few times with (faucet) water....then antifreeze and rain water and finished. Not a problem....do a few other machines the same way. All running young.