Radiator Flush

I recently posted about my successful attempt to install a thermostat on my vehicle. This saved me quite a bit of time and money and I became a little more comfortable with and adept at performing my own automotive repairs.

Prior to that repair, though, I put "Stop Leak" into my radiator/engine cooling system. The product's name says it all. It's supposed to find and seal (some) internal leaks. Since my vehicle is operating at a higher temperature than normal and nothing comes out when I open the radiator drain, I and mechanics I've spoken to, believe there's a blockage in the system - probably a clump of Stop Leak.

My local "Super Lube" location would be more than happy to address this potential blockage for $69.99. As it turns out, all they'd be doing is attaching a hose to my system and running water through it to flush out any blockage. Sorry, but that's hardly worth $70, to me.

I found out that there's a radiator flush kit available at AutoZone and Advance Discount Auto Parts for around $15. That kit, a garden hose, a razor, a pair of pliers, and a flat-head screwdriver were all I needed to flush the system, myself.

Below is a picture of the two heater hoses (center of the photo). I chose one, then used a razor to cut it in two. Then, I placed a plastic tube, called a "TEE," between the two pieces, reattaching them with fasteners from the kit. The TEE effectively reconnects the hose, while adding a place for me to insert a water hose.

Below, you can see my garden hose has been screwed onto the TEE so that water can flow into the system, pushing out all the coolant/radiator fluid plus anything that might be obstructing the flow the radiator fluid.

Once I turn on the water from the garden hose, everything in the radiator and engine coolant system should be pushed out of any available openings, like the top of the radiator (once the cap has been removed). There's a piece in the kit that temporarily replaces the radiator cap with a tube. This allows one to direct the flow of radiator fluid into a receptacle for proper disposal. I don't have a typical radiator cap so I couldn't attach that piece. I just put a bucket under that area of the truck to catch the overflow from the reservoir shown below.

I let the water run until the fluid coming out of the radiator was clear, which means it was about as clear as it was going to get. Unfortunately, there was still no fluid coming from the radiator drain (at the bottom of the radiator). So, I put the cap back on the radiator reservoir.

This increased the pressure in the system because the water couldn't get out from the top of the radiator. As a result it pushed the blockage out of the bottom of the radiator, which is just what I wanted. The radiator drain began to leak and Stop Leak material. Once the flow from the radiator drain was consistent and the water was clear, I disconnected the water hose from the TEE and put a cap on it. Now, the TEE is part of my heater hose and any time I need to flush my system, again, I can just hook the garden hose up to it, again.

After closing the radiator drain, I put fresh coolant in the system, then replaced the cap on the radiator reservoir.

Mission accomplished. I'll let you know how it goes. The next week and a half will be pretty busy, but I'll post when I can.


I had to put this together pretty quickly, so it's not as clear and succinct as I would've preferred. Sorry about that.

If you have any questions or comments, feel free to mention them in the comments section.