Draining cooling system

[Stallion]

Okay, I have to drain my anti-freeze (intake removal) and I need to know how to do this. I couldn't find it in the service manuals on how to do this. They talked about stuff like reverse flushing, but not about what I want to do. I want to get all the coolant out.

And then putting new anti-freeze back in, how would you do this?

Thanks!!

TR

 

[Bob Chadwick]

I added Prestone's block flush per instructions and added a back flow kit. Using the back flow kit, I flushed the system completely.

Some will suggest that you need to remove the drain plugs in the block. After hearing the pros and cons I did not.

 

[Stallion]

But isn't there a stock way to drain the coolant?

 

[Bob Chadwick]

Opening the petcock on the radiator will not drain the block completely. That will require removing the drain plugs in the block.

 

[Stallion]

Where exactly are these drain plubs on the block? That doesn't sound too bad. And is this "petcock" on the radiator at the bottom of the radiator for drainage?

Thanks!!

TR

 

[Bob Chadwick]

The petcock in on the bottom of the radiator. Sometimes it is just a bolt screwed into a hole.

The drain plugs sound simple. However they are usually rusted in place, etc., and not as easy as it sounds. Here is my post last year on the same subject.

 

[Stallion]

Okay, I'm going to drain the whole cooling system and put in new coolant (50/50). I'm just going to drain through the bottom of the radiator and the drain plugs on the block.

Where exactly are these drain plugs? Any pics or description as to how to find these?

Thanks!

TR

 

[Stallion]

Any ideas? And what anti-freeze should I go with? Just something I can pick up at the auto store?

 

[MaineShark]

You can always take it to a shop and have them power-flush it.

In any case, I'm not sure about the block drain plugs, but the temp sensor in each head can be removed, to drain the water out of the head. They are below the exhaust manifolds, between the clyinders - I can't recall off-hand which two, but you should be able to follow the wires, and use an inspection mirror to see the sensor.

Joe

 

[Stallion]

You can always take it to a shop and have them power-flush it.

In any case, I'm not sure about the block drain plugs, but the temp sensor in each head can be removed, to drain the water out of the head. They are below the exhaust manifolds, between the clyinders - I can't recall off-hand which two, but you should be able to follow the wires, and use an inspection mirror to see the sensor.

Joe

About the head draining, I can't imagine that would get all of the coolant out of the block, would it? I want to drain the whole system. How would I do this? bobchad, are there these plugs on the block? Where?

 

[Bob Chadwick]

TR,

They are there on the block. You'll see them if you get the car up on jackstands and get under there.

I don't recommend that you take them out unless you have some kind of cooling problem. If you have problems getting these things out and create a leak you are talking about towing the car to a shop for repairs. I would follow some of the other suggestions for flushing the system as this will also get all of the coolant out.

Bob

 

[mvftw]

I would NOT remove the freeze out plugs out of the block! You are going to open a can of worms.

 

[Stallion]

Okay, I won't open those plugs on the block, but then how could I do a full flush on her? I know you recommended "Prestone's block flush", but what would you need to do? No permanent things right? Would that be best then?

 

[Bob Chadwick]

TR,

Go back and read through this post and the referenced posts and I think all of your questions will be answered. As for antifreeze, I use the green Prestone.

Bob

 

[Stallion]

Guys, quick question...why would you drain your cooling system? I only thought of one reason, that the anti-freeze is murky and dirty. So, I looked in my resorvoir (sp?) and it is pretty blue and pristine. So maybe I should just add to it?

 

[JonM]

Coolant contains special chemical additives to prevent serious damage from rust and corrosion. However, over time, the additives wear out. This depleted coolant becomes acidic and can actually corrode the metals in the cooling system.

 

[MaineShark]

The coolant in your reservoir should be green, not blue. Blue should be washer fluid, which shouldn't be in your coolant reservoir.

In any case, a periodic coolant change is similar to an oil change: the fluid deteriorates over time, and should be replaced periodically.

Personally, I'm planning on changing my coolant twice yearly, since I want to run 33/67 (antifreeze/water) in the summer, and 50/50 in the winter.

But I'll probably have it flushed only once a year. The flushing removes any contaminants that find their way into the system, so they can't harm the engine.

Joe

 

[Stallion]

Joe, you don't flush it yourself? Do you take it to someone else then?

 

[Bob Chadwick]

TR,

I'm getting the sense you are struggling with this. You just need to go ahead and get your hands dirty. Once you get under there you will be surprised at how easy it is. This is one of the first things I did and it will familarize you with where some of the things are under the hood.

Go to the store and buy some Prestone radiator flush, either a back flush kit (what I did) or a new thermostat gasket and enough coolant to establish a 50/50 mix of water and anti-freeze (the Model Center says yours takes 20.7 quarts, so you will need three gallons). I would also replace the thermostat with a new thermostat of 180 degrees just to be on the safe side, but that's just me. I also replaced the radiator cap at the same time. $15 bucks of overheating insurance for both as I recall.

Run the flush through it as recommended on the can. Let the car cool (NEVER OPEN A HOT RADIATOR), open the drain on the bottom of the radiator and either add the back flush kit (what I did) or pull off the thermostat housing (two bolts to do this). Close the drain on the radiator once it drains.

If you pulled the thermostat housing, scrape the manifold clean of the old gasket (make sure you get all of the old gasket off or it will leak. I learned this the hard way). Put the hose in the radiator and run it until clear water comes out of the manifold.

Turn the water off, drain the radiator again, close the radiator drain, replace the thermostat housing and add 10.35 quarts of antifreeze and fill with water (you will have to start the car to get the thermostat to open to accept that much coolant and/or water but don't start the car until the radiator is full). Once full, replace the cap, check to make sure your overflow bottle is within specs and you are off and running. Run the car, watching the temperature and monitor your overflow bottle. If you had air in the system, it will burp out and be replaced with the coolant in the overflow bottle.

If you bought the back flush kit, follow the directions with the kit. You will run the car and eventually get clear water out of the radiator neck. Once you have followed the instructions, drain the radiator again, close the radiator drain, add the cap to the backflush valve and fill as indicated above.

Hope this helps.

Bob

 

[jonstr]

TR -
Bob's correct. You just need to dig in. I have always gone through this every time I need to do something on one of the cars that I've never done before. When I finally just get started, it's never as hard as I thought it would be.

But looking back to your original post, you said you were going to remove your intake. I have always just let the car sit over night and then drained the radiator and expansion tank. I give the upper radiator hose a squeeze or two to push out any excess coolant, and then disconnect it at the thermostat housing, lifting it to let it drain back into the radiator. This is where it can get a little messy, particularly if the coolant didn't drain back in to the block or radiator before the thermostat closed, so pack a few rags around the housing first. Usually squeezing that hose will tell you if you have alot of coolant in there.

From there, I just pull the manifold. I generally have found that the coolant will settle down below the intake manifold level and there is never more than a little seepage of coolant that I need to clean up. I'm sure there are better ways to do this, but pulling the plugs to drain the block always seemed to cause more trouble then it was worth.

Jon