Best / most effective way to flush the radiator?

All i've ever done before was disconnect the lower hose and stuff a garden hose in the top radiator cap, and turn on the hose. I know this can't be right, and haven't been taught correctly (obviously). I've done some searching and can't really find much. I did find though that a guy pulled his thermostat out, but couldn't really find what that does. I can only figure for more flow, but how do i flush the radiator to get everything to flow thru the thermostat.


Or can someone please help, and tell me the usual procedures to do a correct radiator flush?

thanks, and sorry for the newb post

go to your local parts house and pick up Prestones radiator flush kit. It includes every thing to flush your engine. The proper way to flush your cooling system is to turn on the heater on full and allow the engine to reach operating temp. after you have installed the flush kit

rebelcherokee said:

go to your local parts house and pick up Prestones radiator flush kit. It includes every thing to flush your engine. The proper way to flush your cooling system is to turn on the heater on full and allow the engine to reach operating temp. after you have installed the flush kit

Click to expand...

I disagree with the chemical flush. Every time I have tried this my water pump bearings go out within a month. I now always use white vinegar (about $1/gallon at the grocery store). Just empty the system as best you can and refill with the vinegar. Run it for a few days (I have left it in for as much as a couple months with no negative effect...in the summer) and drain it out and flush very good with water. Then refill with your 50/50 mix and you're good to go.

The way the Renix radiator is set up, their is no good way to mechanically flush the radiator, except to pull the radiator, stand it on end with the drivers side on the top, and fill / flush from the top down.

Jess said:

I disagree with the chemical flush. Every time I have tried this my water pump bearings go out within a month. I now always use white vinegar (about $1/gallon at the grocery store). Just empty the system as best you can and refill with the vinegar. Run it for a few days (I have left it in for as much as a couple months with no negative effect...in the summer) and drain it out and flush very good with water. Then refill with your 50/50 mix and you're good to go.

Click to expand...

so should i just take bottom hose off, drain. put back on take top hose off, open my radiator cap, turn on XJ with heat on, then stick the garden hose in the radiator cap, and flush away.


Then seal everything back up, throw some white vinegar in there, fill the rest with water, run it for a few days, then throw in the 50/50 mix?


does this sound right?

If you want to use a kit (easier)

http://www.diynetwork.com/diy/en_maintenance/article/0,,DIY_13808_2270919,00.htm

If you want to flush with water 2 or 3 or 4 times (or until the water drains clean)

http://www.associatedcontent.com/article/120951/diy_automotive_tips_flushing_your_car.html?cat=27

You don't need chemicals for either method.

Which side is the radiator cap on? If it is on the inlet side, that would just flush acumulated trash on the inlet side into the tubes. Also you need an opening, or outlet as well as an inlet to do a flush.
The chemical flush is designed to chemically disolve calcium scale off the radiator tubes and engine walls to increase the heat transfer rate. Calcium and other salt scales (the white and yellow crud) act like insulation and trap heat inside. 1/64th of an inch of scale in the radiator tubes drops the heat transfer rate by a good 30% to 50% or so.

Vinegar and DI water with a bit of water soluble oil added to lube the water pump seal might make a lot of sense.