I bought my 1997 S-10 in 2000. Coolant was always rusty. I have had it flushed several times. Pep Boys said they could only use DEX cool on GM products. My radiator sprung a leak and had it replaced. Again, coolant was rusty brown. I again had the radiator flushed but had them to use different coolant. My truck overheated again and there was a hole rusted in the thermostat housing. I replaced the housing and thermostat (very rusty)and flushed it out myself. Coolant is still rusty. I am loosing just enough coolant to be aggravating. I have to add coolant every trip. Intake manifold seems to have a leak. Mechanic quoted repair at $4.50.