4.0L Engine Coolant/Flush

[Jim Cissell]

I was wondering if simply detaching the bottom hose on my 4.0L Jeep Wrangler radiator and runn ing fresh (hose) water thru the top for a couple of minutes (while the engine is runningof course) would sufficiently flush the cooling system? I wanted to keep the procedure simple so I would actually do it, rather than put if off awiting a bigger time slot due to a more 'involved' flush.

Thanks, Jim

 

[got boost?]

usually the bottom hose is the return line that feeds the water pump, disconnecting that would starve the engine of coolant. this method is sound though: disconnect the hose that flows hot coolant FROM the engine to the radiator (top hose)and let it drain into a bucket, continuously fill the radiator with water, it will take a while to do this however.

[ March 13, 2006, 02:51 PM: Message edited by: got boost? ]

 

[Eddie]

I put a flushing tee in the heater hose and flushed that way. Prestone makes the kit for about 6 bucks and it works very well.

 

[Gary Allan]

Open drain cock on lower passenger side of rad. Hang hose in top of rad. Regulate a near "no overflow" ingress/egress flow.


Run until clear.

Leave drain

Close drain

Refill.

 

[Dark Jedi]

to add after refill. let the engine idle with the radiator cap off. so all the air bubbles can get out and when the bubbles stop you can pu thte cap back on. have heard air bubbles can cause the engine to run hotter,

 

[Chris142]

There is a special way to refill the jeep engines. You need to fill it through the heater hose that connects to the stat housing.

Remove the hose, put a funnel in it and fill it through the hose, through the heater core untill coolant comes out where the hose connects, Put the hose back on and top off the rad. Run it till the stat opens and shut it down.

Check the level, fill and repeat.

Removing the lower hose wont get anything done. Remove the stat (or heater hose on the housing) and lower hose and run water through it that way.

Bottom of the rad will have a drain...........Don't bother trying to remove (or find) the block drain as it's a Pain in the arse to acess.

 

[Matt_S]

I take it you have no draincock? If you do, I'd use that. Detaching the bottom hose is going to cause a torrent of coolant to come out, leaving you with air pockets in the motor that you won't be able to eliminate with a garden hose. I wouldn't run an engine under those conditions.

There are also environmental problems. Coolant is very toxic. You should catch the coolant and recycle it, or at the very least, pour it down a sanitary drain. With your plan, it'll be difficult to catch everything coming out of there.

I think an ideal plan would be to locate the block drain, then drain the block and radiator, which will get everything out, run the engine up to temperature with some fresh water, adding some radiator flush chemical if you prefer, or not, then drain and catch all of that, then refill with coolant. I know it's not as simple as your plan, but IMO it's the right way to do it.