Mellis67

I'm trying to do a coolant flush in my 2000 Cherokee 4.0 . This is my first flush and my Cherokee's first I believe. I am really new to doing my own service but I have found this site very helpful. My bolts for the airbox were pretty well rusted so I opted for draining via the radiator drain plug rather than the lower radiator hose like a lot of people suggest. I turned the petcock a quater of a turn and it seemed to stop but I get no flow out of it. Does it take more than a quarter of a turn to open it? Could it be plugged? My coolant is very nasty and it seems to be gelled just under the radiator cap. I have no problems with overheating or leaking I just wanted to do the service before problems develop. Any ideas what I can do to get this flowing? Or should I give up on the drain and find another to empty the system?

tjwalker

First flush on a 2000 is waaaaaayy too long of an interval. How about other fluids like transmission, transfer case, differentials? Should not ignore fluids as they are the "lifeblood" of your engine. Especially cooling system maintenance on a 2000, which has the 0331 head, which doesn't need a lot of encouragement to crack.

Not sure if I'm understanding you as the lower hose should absolutely be accessible, even if you have to move the rubber splash shroud a bit.

It may take more than a quarter turn for the petcock to start draining. But if this were mine, I'd tighten it and go for the lower hose. You damage that petcock (they are frail and under-designed) and you've got bigger fish to fry.

You are going to likely need to perform multiple flushes from your description. Consider using a flushing agent for an abused system available from any parts store. Follow instructions on the bottle. Use conventional (green) anti-freeze in a 50-50 concentration when you're done. And replace the thermostat while you're at it with an OEM Jeep 195 unit. Check and replace all hoses as well. Dollar for dollar, no better money spent than that spent on cooling system maintenance.

mike96xj

Lock that drain plug again. And pull your lower radiator hose.. quick and easy. Be sure to have something to drain into..

Lowrange2

Turn the valve until it come out. It's on a "leash" so just let it hang when it's unthreaded all the way. Like dude said, be VERY careful when threading it back in. Do NOT cross thread it.

Why are ya'll so scared of the damn drain plug?

djb383

Removing the air filter box makes for easy access to the rad hose clamp on the water pump. Ooops, sorry, missed the rusted bolts but still worth a try.

tjwalker

Plenty of threads of broken petcocks. Much safer (and easier) to drain via the lower hose. You only have to remove the one end of the hose where it attaches to the radiator; you don't have to remove the hose completely.

You can access it from underneath; I do it that way on my 99 and that should be the same as your 2000. Just get a big catch pan ready and use eye protection as when it comes out when the hose is loosened, it comes out with some force. Ask me how I know.....

Knucklebuster

You'll need to take that airbox out eventually for a lot of other service and/or inspection - belt, power steering hoses, transmission cooling lines and more. Time to bite the bullet and pull that airbox. Soak the airbox bolts in P Blaster or Kroil and wire brush where you can reach Soak them again. While you're at it, blast the coolant drain valve. Let it sit overnight if you can. If I remember it's two bolts and one nut. Loosen them 1/8 turn at a time and tighten back up. P Blast again. Loosen and tighten a little at a time. If the bolts snap, you can still drive the Jeep. If you need to drill out the old bolts and re-tap the holes, you will learn a skill that you will need almost every time you work on your Jeep. Arrrggghh!

Mellis67

Got the bolts/nuts soaking in blaster now.. I'm draining into a bucket so the approach from the top seems a better way to control where it's going. That and like it was said I'll be battling the airbox again soon anyway. I managed to replace the power steering lines last week without removing it but what a pain in the *****. If the bolts snap they snap. At least I'll have fresh bolts when they are replaced.. I'll keep you posted.

djb383

In order to flush the system well and not move crud from one place to the other, I would suggest u also remove the top rad hose and heater hose from the t-stat housing. Stick a garden hose in the loose heater hose (to flush the heater core), then in the top rad hose (to flush the rad) then in the heater hose nipple on the stat cover (to flush the head/block).

No4x4Yet

Just and FYI my bolts are snapped, maybe one left. Doesnt matter too much. The box cant go too far.

fishtaconc

X2^^

DFlintstone

A seized bolt can "listen" to a good smack, and those couldn't hardly be easier to reach. A big long extension, a large drift, a big bolt, piece of pipe. Sharply whack down and give it a few good shocks. For the nut you could set a socket on it. Also you can try going "righty tighty" just a tad, sometimes that does it. (you aren't suppose to strike hard steel like an extension. A chip could fly off, tumble end over end, take out just one thread of your Levies and lodge in your shin, so I would use caution there).

DJB's talking about that there V youtube link

djb383

Hey D, watched u r spider video........ROTF,LMAO.

DFlintstone

I thought it was worthy of sharing....when I change it in a week or so nobody will know what we where talking about!

Mellis67

Ok air box out.. Only Snapped one bolt so I consider myself lucky. Flushed and rinsed now getting ready to fill. How can I be sure I got enough water out of the system before filling? I have been draining by pulling the lower radiator hose. Or should I be good. I plan on filling with pre-diluted coolant 50/50 (green)...