Sebastianc2012

I own a 96 XJ sport, with about 210k miles on it.

Im in the midst of replacing the water pump for the first time, after it failed and the belt slipped off while driving due to im guessing the bearings failing.(made the pully incredibly hard to remove).

Ive removed the electrical fan and belt, and after removing the lower radiator hose from the WP, the coolant was really rusty and sludge like, and only drained a really small amount. Most of it had leaked out after the pump failed, but what leaked out at that point was a bright green almost new looking coolant.

Ive searches and read a few threads and think ive confused myself quite a bit. A lot of places say to fill the radiator with water and let the truck idle for a bit, is this doable with the belt removed? I dont want to overheat or cause any problems.

With the lower radiator hose off, can i just pour water into the radiator until it comes out clean? Or will i have to pull the drain plug? Also the coolant in the resevoir needs to be drained aswell.

Sebastianc2012

Came across this bit of advice, wondering if this would be the way to go

"Disconnect the top rad and heater hoses from the t-stat cover. Disconnect the bottom rad hose from the water pump. Stick a garden hose in the heater hose and flush. Stick the garden hose in the heater hose nipple on the stat cover and flush. Stick the garden hose in the top rad hose and flush."

IJM

I just did this yesterday, and it works perfectly. So much crud came out. Multiple drain and refills of the radiator is OK if all you need to do is get fresh coolant in there, but it won't get all the crud/mud/rust/etc. out. The nice thing about the XJ setup is that you can easily flush the radiator, block, and heater core. My VW and Mazda, not so much, as they use a closed system with a pressurized bottle. That, and the GTI's cooling system is redonkulously complex.

Sebastianc2012

Okay, one last thing im concerned about is where the return is for the water that should be going to the heater core through the heater hose.

If im correct, top rad hose return should be lower rad hose and the return for the water being flushed into the t stat cover from the heater hose nipple should be the nipple on the upper left of the water pump?

If so, then is the return for the water that goea theough the heater core going to come out through the hose that connects to the upper left nipple of rhe WP?

Kingfisher

Just flush both direction.

dschappell

I was planning on this this as well, early next week. Thanks for the info, helped me!!!

IJM

Yes, but flush in both directions as Kingfisher said. I got more gunk out on the back flush than the forward flush. Do it both ways several times until it comes out clear.

djb383

A '96 XJ has a heater control valve (unless it has been eliminated). U must stick the garden hose in the heater hose that's after the heater control valve in order to flush the heater core. Perfect time to eliminate the heater control valve, if u have one.

Sticking the garden hose into the heater hose, water will come out the water pump, Sticking the garden hose in the heater hose nipple on the stat cover, water will come out the water pump. Sticking the garden hose in the top rad hose, water will come out the bottom rad hose. Flush in that order......heater core 1st, motor 2nd and rad 3rd.

Sebastianc2012

Is completely removing the heater control valve something i want to do?

HarleyRob

Is there a way NOT to flush? I mean is there one certain thing to be sure you DONT do when flushing? Like flush in wrong direction some how?

Roler

LOL. I'm sure there are many ways not to flush or things not to use when flushing. But regarding your question, there is not so much of a 'wrong' direction. You will find with flushing the heater core for instance, that you get actually more crud out if you ' reverse' flush it, so opposite direction of how the flow through the core normally is. See the core as a bit of a funnel; the stuff that accumulated is better flushed out the way it came from, so to speak.
You will probably notice that one direction goes somewhat better than the other when flushing.

Flushing up the lower radiator hose wont do much. To reverse flush the radiator you either need one of those pressure kits, or remove the radiator and do it out of the Jeep.

HarleyRob

OK, thanks. Thats what I meant...which direction. My logic (though may be wrong) is to unhook said hoses and flush in/out every opening till clean.

djb383

U bet there is a way "not to flush". The last thing u want to do is flush crud from the heater core and motor into the radiator. Following the directions I post will prevent crud from entering the radiator.

HarleyRob

ok, thanks. and the heater core is the thing where the thermostat is? i'm learning

djb383

The large heater hose and the top radiator hose attach to the t-stat cover. The small heater hose and bottom radiator hose attach to the water pump.