How do I do a coolant flush a 351W?

[mnm99]

I went to replace my thermostat housing gasket today. (I just bought the car) I want to flush the system because of the brown gunk. I always used distilled water in all my motors and never looked like this. What the best way to do it?

Edit. If I ran the car without a thermostat, and left the fill cap off. Disconnected the bypass hose at the thermostat housing and connected a long hose to a bucket. Capped off the water pump bypass. Ran the car while filling at the cap. Would the water flush through the bypass?

[Rick Parker]

Remove the thermostat temporarily. If you have one, open the petcock on the bottom of the radiator or loosen the lower hose to allow coolant to drain in a controlled manner. While the engine is running fill slowly with a garden hose filling at about the same rate as what is draining out. Once clean water is flowing out turn off the hose, let the water drain completely and then fill with distilled water AND a coolant. If you can drain the block separately, do that before refilling.

[Dwight]

follow Rich's suggestion then fill with distilled water and drive it for a few days. Then drain again.
If the water is still brown, refill with distilled water and drive it for more few days.
When you think it's as clear as you can get it refill with antifreeze and distilled water.
In North Alabama we use 25% antifreeze and 75% distilled water. Our low temp. in the winter is 25 degree but the car is inside a garage. We do drive in 35 degree weather but not long.

Dwight

[mnm99]

Problem is I don't have a petcock. I cant see how I can control it by loosening the lower hose either. By doing that your just flushing the radiator. Water goes in the top and just comes out the bottom pretty much. I want to flush the entire system. Do you think If I bought like a 4 ft hose and did what I said with the bypass it would work too? I quess the way I see it is the fluid goes into the top of the radiator, The pump pulls it through the radiator and motor then it will come out the bypass.???

Originally Posted by Rick Parker

Remove the thermostat temporarily. If you have one, open the petcock on the bottom of the radiator or loosen the lower hose to allow coolant to drain in a controlled manner. While the engine is running fill slowly with a garden hose filling at about the same rate as what is draining out. Once clean water is flowing out turn off the hose, let the water drain completely and then fill with distilled water AND a coolant. If you can drain the block separately, do that before refilling.

[mnm99]

Problem is I don't have a petcock. I cant see how I can control it by loosening the lower hose either. Do you think If I bought like a 4 ft hose and did what I said with the bypass it would work too? I quess the way I see it is the the pump will pump the new coolant into to motor then it will come out the bypass. Scroll down on this page and see what I mean

rear coolant passage

Originally Posted by Rick Parker

Remove the thermostat temporarily. If you have one, open the petcock on the bottom of the radiator or loosen the lower hose to allow coolant to drain in a controlled manner. While the engine is running fill slowly with a garden hose filling at about the same rate as what is draining out. Once clean water is flowing out turn off the hose, let the water drain completely and then fill with distilled water AND a coolant. If you can drain the block separately, do that before refilling.

[madmaxx]

Do as mentioned above, in addition there is Allen head screws on the block toward the back you can remove to completely flush block, but that's extreme. The brown gunk u see is probably leak sealant. Once you flush the system you will discover leaks around the horrific water pump design. I would drain and flush raidiator. Fill with water drive flush, install antifreeze. Distilled water in this case is like marking a piece of wood with a 5mm pencil and then cutting with an axe. Use at minimuim 180f thermostat.

[Dwight]

no petcock, no problem

Just loose the clamp on the lower hose and move it out of the way. Work a screwdriver under the hose till water drains out. You have about four gallons of coolant so have enough pans to catch it all. I have used a short plastic box that I bought at WalMart. The ones with a lid used for storage.

Or the pan you use to drain oil into will work.

Dwight

[Dwight]

Madmaxx
we use distilled water because we have a lot of limestone in our tap water


Dwight

[mnm99]

I have one of these necks in the middle of the hose. http://www.summitracing.com/parts/hre-3423 . I first removed the lower hose, drained , connected , filled and ran the car. I did this 4 times. Brown crap still came out...I then just disconnected the lower hose, stuck my garden hose in the filler. Water came out of the lower hose and radiator the same time. I did this until it was clear.. There was still a lot of crap! I then connected the hose and was able to put 2 gallons of distilled water in. I think I'm going to drive it for a week or so. Drain it again and add the 2 gallons again. If I do this 3 or 4 times I should have all distilled water in the entire system. Then the last time I'll drain , add 1 gallon of anti freeze and the rest distilled.

Originally Posted by Dwight

no petcock, no problem

Just loose the clamp on the lower hose and move it out of the way. Work a screwdriver under the hose till water drains out. You have about four gallons of coolant so have enough pans to catch it all. I have used a short plastic box that I bought at WalMart. The ones with a lid used for storage.

Or the pan you use to drain oil into will work.

Dwight

I understand, but if I fill the top of the radiator and it drains at the bottom how does it flush the ENTIRE system?

[DAVID GAGNARD]

Easiest way to flush the engine is remove both radiator hoses from the radiator,you'll also need to take out the thermostat.......
then stick your garden hose in the top hose a few inches and turn on the water full blast,it will go thru the block and out the lower radiator hose....

David