Any tips on refilling "closed" coolant system?

[georgedexter]

My loyal, sometimes painfully dumb 18 year old son managed to crack the plastic coolant recovery bottle on his '89 4.0 wide open. He admitted that he knew it was "a little cracked" and drove it anyway. (That's the dumb part) Poor kid had a jeep full of surfboards and girls but alas the heat and traffic won out and the crack went major. I believe it had been leaking water/sucking in air until he was just making steam. Would steam pressure blow out cracked bottle and spew remaining fliud out? No water in oil. No problem finding a bottle at junkyard,but would like some tips on refilling system. All I can think of is to keep filling the bottle,heat up the jeep and hope the engine sucks it in. Someboby must know a better way. Happy 5th of July!!

[jnovgrod]

I just had to refill mine yesterday. The haynes manual has a section on it but I found it to be less than helpful. I ended up taking the top radiator hose of the engine side and filling the hose and the thermostat housing with coolant. Then filling the bottle to the top of the post inside the bottle below the cap and bringing it up to normal operating temperature with the cap off the bottle and adding more to keep it to the top of the post. This worked for me. Hope this helps,
Jordan

[Edbrooks]

I disconnected the heater hose at the T-connection where the control valve is. I inserted a standard garden water nozzle in there and turned on the water, low volume. This puts water past the water pump and thermostat into the block itself. When water runs out the other heater hose (which is now disconnected) the block is full. Run it a bit longer.

If instead you want to put in anti-freeze, still disconnect the water hose at the heater control valve. This time use Visegrips (lightly) to hold the end of the hose vertical and insert a funnel. You can now pour a gallon of antifreeze into the funnel and again, it will fill the block. You can, of course, pre-mix water/anti-freeze in a gallon jug and use that instead.

[Saudade]

LOL... I've had a lot of "fun" trying this. I ended up running the engine at fast idle until hot, then shutting down and wait until it cools. Then fill the bottle until it reaches the full mark. Then repeat this until the level in the bottle remains reasonably high (between add and full). I know I have enough when 2 things happen.

1. Coolant flows out of the return and out back into the bottle when the engine idles.

2. The electric fans kicks in when the needle gets slightly past half way.

Bottom line is my '88 runs MUCH cooler now and I don't have to run the a/c as much (it turns on the electric fan).

[rotorfloat]

My experience with the cracked recovery bottles has been from the pressure cap failing to vent. If you get a replacement bottle from the recycler, it would be recommended to buy a new cap, for putting the old cap back on will give you 2 cracked bottles.

jnovgrod's filling method has worked well for me too.

Go Jeep!