Re: Flushing out radiator? (rusty colour)
I had a mid 80's car that the coolant turned brown in the minute I poured it in. The lady I bought the car from had it serviced regularly at the dealer with receipts for the 80K miles the car had on it. I changed, flushed, changed, flushed with no result. I finally drained, refilled with tap water, drained, refilled with tap water, pulled the upper radiator hose, and ran the car with the hose in the radiator and the upper radiator hose discoed. When the thermostat opened I had to increase the water supply as the upper hose was discharging hot water on the ground. I ran it this way til the engine was well up to temp and the discharged water was clear. I redrained, and filled with coolant only til I was at the 60% of what the system held. I then topped with distilled water.
I knew I could never totally drain the block, so this method ensured that I had at least a 50/50 with some wiggle room. I did not like the idea that there was a certain percentage of tap water in the block, but it was never a problem in the next 190 thousand miles. The coolant stayed clean til I sold the car.
This might be an easy way to get that rust out cause it does not sound like you have a bad sediment problem, just rust that was allowed to build.