96XJ_MrFantastic

I'm taking my XJ on a trip through the mountains to a cabin. There will likely be snow on the highway leading there and 4-hi at least will likely be necessary. Round trip will be approximately 400 miles. I have a heater hose leaking coolant so in a few days I'm eliminating my HCV, replacing both heater hoses and also replacing both radiator hoses as well. While I have the hoses off I am going to do a coolant flush. There's a lot of info out there regarding best methods and such. My flush method is as follows:

-remove lower radiator hose and let drain
-flush radiator with water until clear
-flush coolant reservoir tank
-remove heater hoses and backflush heater core with low pressure. Then flush other direction
-flush through water pump housing nossle (one connected to heater hose) to bypass t-stat since it'll be closed while cold
-spray air through hoses and such to remove excess water
-attach new hoses and clamps
-fill radiator with 50/50 self-mixed solution
-run engine (no rad cap) with heat going until t-stat opens and refill radiator as necessary
-once at operating temp allow to cool completely and top off reservoir tank
-go for a drive, test HVAC, allow to cool again and check levels. Add fluid as needed
-have beer

Does that sound about right? My coolant in the radiator is clean and green and I have zero overheating issues but I know it won't hurt to get everything flushed and clean.

It has had a recent 4x4 tune up including fluids (diff transfer case, engine oil/filter, etc), new plugs/distributor/etc, rear drums rebuilt approx 3k miles ago and front brakes approx 8k miles ago. New BFG KO2s. New fuel filter as well. Rear main, valve gasket, oil pan gasket replaced recently.

I'm going to carry extra oil and coolant with me on the trip just in case. Anything else you guys would consider checking prior to a 400 mile trip?


​​​​​Pic of the ol girl:

downs

Make sure to use distilled water if you are mixing your own. Tap water and filtered water are a nono you don't want any extra minerals in there with your coolant.

MonacaYankee

F1Addict

My road trips [see sig] are always between 500 and 4,000 miles. Every year I take several 1,000+ mile road trips that include epic off-road stuff. I've never been left stranded. You seem prepared. I was really nervous and over-prepared the first time, too. Take a deep breath, know that you've done everything you can and enjoy your trip.

jordan96xj

Beautiful 96!

Because the weather might be spotty, make sure the windshield washer reservoir is full. I've noticed during the winter, I can go through that stuff quickly, and it would suck to run out when you need it most.

Jeepwalker

1) I don't understand why you don't just swing by a hardware store on your way out of town and pick up another couple hose clamps for $.50 ea? Get a couple thin ones that are just large enough (not too large) and install on the little bit of remaining hose next to the existing hose clamps (put screws 180* apart). Then you can enjoy the trip w/o worrying about coolant.

2) You might someday regret removing the heater control valve. Especially on a hot summer day when you ask yourself why the heck it's SO hot in there. I know some have done it w/o problems, but as your seals start leaking (??). You're really not gaining anything by taking it out of the system other than adding one more cobbled up item. A lot of guys who have classic cars ...and other vehicles actually put them IN. I personally wouldn't remove mine ...but hey, whatever.??

3) Double-that on the purified water. Purified is better than distilled, but as pointed out, don't use tap water (ever!). When I grew up, every car we had had crapped-out radiators primarily because my dad and everyone we knew just added tap water. They'll really get deposits in them if you do.

4) Before removing heater hoses, get under the hoses from the backside with a 90 or 180 degree pick and work it around to separate the rubber hose from the metal heater core ends. Or cut the existing hose with a razor knife and peel away with a screwdriver. It's not worth prying or tugging on the hoses to get off. They could be stuck on pretty tight.

5) After you remove the hoses, back-flush the heater core by sticking a water hose end (that's turned "on") onto the heater core OUTLET end. You might get a lot of crap that'll blow out. Maybe after that, take a short hose and a funnel (holding the funnel up 10") and pour purified water in to displace the hard tape water.
BTW, the heater hose which comes from the thermostat housing should be the supply hose to the heater core ....so you can figure it out from there.

It's a pretty easy job. If you have any doubts about your water pump, changing it before you do the flush would be a good idea. Not too hard on these vehicles.

96XJ_MrFantastic

Thanks everyone! Yep, I'll be using distilled water for the mixing. The newer XJs don't have the HCV and most people who have elimated them report no negative effects. I do not drive often so I'm not worried if it makes the cabin a bit warmer. I will also probably just cut the hoses and then take my time getting the excess off the fittings.

I am right in thinking I can flush the block by using the water pump where the heater hose connected, right? That way I can bypass the t-stat?

00t444e

My 97 came without a heater control valve, no issues with it getting to hot in the summer, that's what the blend doors are for. When I flush the system I remove the thermostat first, then I drill a small hole in the new thermostat to make filling it up much quicker, because you don't have to wait for the thermostat to open.

dave1123

Just something that might come in handy. Take a star (cross) tire wrench. You'll thank me if you have to change a tire on the road quickly, especially with those deep set lug nuts. I go the extra mile and spray the one socket I need a different color.