Where Is My Radiator Cap?

ScottyBoy · August 23, 2007

I want to do a coolant flush on my 2001 suburban and I cant find a cap on my radiator. Is there one? Or do I fill it thru the reservoir? Also, what is the best/easiest way to flush my cooling system at home?

C & A s Dad · August 23, 2007

The cap is the res cap. It is a presurized res and the cap on it is your only fill.

Depending on your miles, I would recommend changing the stat at the same time.

Cliff Notes version of flushing at home.

Drain the system with it cool. The draincock is located at the bottom fo the radiator on the drivers side. Be sure to catch coolant and dispose of it properly.

Make sure both front and rear heaters are on and fans blowing on high.

Refill with water and a mild flush such as Zerex or Prestone.

Drive it for 10 to 20 mins after it reaches operating temp.

Let is cool a little, drain and refill with water and drive again. Most people will only do this once. I recommend at least doing this step twice and 3 times if time allows. I like to be sure all of the flush chemical is gone.

Refill with 50% Dexcool approved coolant (Not the green stuff or the new Universal coolants that are avail) and 50% water. Some people use Distilled water and there is much discussion if this the proper thing to do or not. If your local water is really mineral heavy, I would use distilled water, if not use your tap water. Some research has shown that distilled water contributes to Electrolysis which I will comment on in a minute. Make sure you drive it with both heaters on and watch the temp gauge for fluxuation. You should not have to do it, but on occasion the system will have trapped air making the temp gauge fluxuate. If so, the system would need to be "burped".

Once you are done, I highly recommend adding a bottle of Lubegard's Kool It, part # 96001. This product will eliminate any chemical electrolysis that could occur in your system. It is also recommended in writing by Modine Radiator Co. and is an excellent product.

There are other methods including removing the radiator hose etc. but IMO, this is the best and most simple way to do this at home.

ScottyBoy · August 23, 2007

Ok, sounds pretty easy. But a few more ?'s now. How do I burp the system? where can I buy this lebegard stuff? And is that prestone orange aintifreeze (that they claim lasts 5 years) any good? Not that I'm planning to actually go 5 years, but is it pretty good to use in my radiator?

C & A s Dad · August 23, 2007

The only vehicle that I ever owned that I had to burp was an Intrepid and the radiator was mounted lower than the motor. On our trucks this is not the case. However, the Intrepid had a bleeder screw on the thermostat housing. I had to run the car up on ramps getting the radiator higher than the engine and with it running and warm, I had to open and close the bleeder screw until no air came out.

I will have to let a real Tech chime in here about burping a truck with no bleeder screw. I have some ideas but do not want to mislead you. I do not feel this will be an issue but again, lets see if a Tech will chime in and help you out.

I work for CARQUEST and we sell Lubegard but I see you are located in Shreveport and we do not have any stores in your market. You will need to visit Lubegard's website and locate a distributor in your area.

The Prestone orange 5 yr antifreeze is the Dexcool approved coolant I mentioned. It is what is designed and recommended for your truck. It is really good coolant but I would not suggest leaving it in for 5 years either. Make sure whatever brand you buy, that it actually says "Dexcool" on the bottle. There are several new "universal" coolants on the market (including one from Prestone) that are claimed to be compatible with almost every coolant out there. They may be, but why use a Universal coolant when you can buy what was designed for your truck.