Review on 💦 Lisle 60900 Heater Core Backflush Tool: Efficient Solution for Flushing Heater Cores by Russ Mashlan

I am a professional mechanic and I have never had the opportunity to try this tool. I have a Chev Blazer that I physically replaced the heater core on 10 years ago. Well a few months ago it was clogged and I wanted to spend the day removing the whole dash again to replace the core. I saw this tool on Revain and realized that I really have nothing to lose but a lot to gain. By the way, you can isolate the defective core by feeling the temperature in the two hoses of your heater, if any. When working properly, both will be hot during normal engine operation. When plugged in you only have one hot (inlet) the other (return) is much colder or just colder. Okay, back to my use of the flush tool. I just disconnected my hoses from the heater on the firewall and adjusted the lengths to 3/4" and 5/8" and then installed a Lisle flush tool on the end. outlet hose and began the "backwash" process. I just flushed it with water in that direction for about 25 minutes until the water flowed out at a good rate. So I reconnected my original hoses and poured coolant into the radiator (reservoir on new cars) with the engine running and was very surprised and relieved to find my heater core working like new again. I am still amazed at the simplicity of this tool and its ability to safely clean such a complex and time consuming part of my truck. I didn't even have to use a chemical additive. I'm not sure if a heater core with excessive deposits (on engines that don't use the coolant in the right mix with water) would benefit from a backwash, but it's worth a try, maybe adding a chemical solvent to the flush mix radiators after flushing. initial core flushing through a connected makeshift drain hose. After adding the additive, leave the additive in the active zone for at least a few hours (follow individual product label instructions), then flush again and see if flow is restored. I wish you success. I hope your Lisle Flushing Tool saves you the time and money it saved me!