unidentifiedbomb

Hi there,
I have an 88' XJ and I want to flush the system and put a proper 50/50 before the heat of the summer comes. My jeep is my first vehicle so I learn things as they come, this is a new learning experience so please be as simple and step by step as you can. I appreciate all those who help.

DFlintstone

Others might know better than me, but I have a thing or two. The E-fan comes out with just two screws and a plug. Now you can reach the lower radiator hose. (No fun), but once you have that off, with a garden hose, wherever you can rinse from, (upper hose, inner heater hose @ T-stat housing), crud can come out there. The drain **** is a joke, don't even touch it.

You can disconnect the heater hoses into the firewall. (careful with that valve! REALLY CAREFUL!). It might just crumble!.. With hand pressure, hold the hose on one heater hose, (into the firewall), then the other. Go back and forth a bunch of times to flush the heater core.

I might start with (some product). I might even bypass the heater core for that to rule out loosened crud ending up in there. (bypass, meaning connecting the two hoses that go into the firewall together.) Then after, "the product", had had time, pull that lower hose.

Don't run cold water into a hot engine!

hbracing13

What I usually do is drain the rad out out from the plug or can do lower rad hose just depends on now much time you wanna spend on it. Then fill with water like around 2/4 times depending how bad it is. Then on the last drain I fill with just coolant and call it good been doing this on all my vehicles with it being close to a 50/50 mix.

DFlintstone

Larger pieces won't fit out the drain, and smaller pieces can lodge in there, then you have another problem. (can be a real )

highmileage

One way I have done this on my Jeep...
Disconnect both heater hoses from the diverter valve(if you still have it)
locate the heater return and place a water hose nipple into it, hook to water hose(turned on about quarter the way) start and turn the water up. You can also do a reverse flush as well through the other heater hose.
As per Dflintstone also do the heater core flush and radiator drain.

JackJare9455

a coolant flush at a local lube shop isnt a bad option...

its usually around 65 bucks and they flush and fill the coolant system with a 50/50 mix...

You can use some coolant flush in there before you go up to the shop...

I like this method because its

A. Easier on you
B. They dispose of the coolant properly

Its a little more money to do it this way, but a lot less of a headache IMO.

Im always a big fan of doing all my repairs myself, but this is one of those that I outsource LOL

When I did my water pump and radiator, I was able to flush out my block and head really well, but next time I want to replace my coolant, I'm going this route

hbracing13

+1 usually the lube shop will dispose of it, if its just coolant. When its mixed that's a whole another story.
Something are worth the hassle because you do a better job and its way less then other work, plus if they mess up something because they forgot to plug the fan, tighten a hose in its all on them.

DFlintstone

JackJare9455

not a fan?

unidentifiedbomb

I have read about the Preston's flush kit and will probably go that route to make it easier. What would be easier to flush through, radiator plug or lower hose? And do I need to unplug the fire wall cables or can I just flush the whole thing at once?

DFlintstone

I rarely even go to tire shops..unless I can't avoid it! (or am going to get info on what they messed up).


unidentifiedbomb, "unidentifiedbomb", might be a good name for that drain. When crud lodges in there, you can't screw it back closed. Also anything on the bottom of your 20+ year old system bigger than seed won't "flush" out. (not to mention "flow", well, won't really be in the equation). "I'm doing a dribble flush?)

unidentifiedbomb

I want to get as much crap as I can out with the smallest headache. You're making me worried about the heater cables breaking as I can't afford to break anything. So did you say it's a bad idea to just leave the cables connected to the heater and flush it?

DFlintstone

See Post#15. I believe the "heater return" is the line closest to the valve cover that runs to the left (drivers side), of the t-stat housing. I think he is saying run the hose there with it running, with the lower hose off.

Very unlikely a shop would so more than just drain it, (if that), and make it look pretty for you. (they might even put coolant in it from the car in the bay next to it!)

unidentifiedbomb

So just remove and replace that line with the hose and let it all flush through with the engine on to open the thermostat? Seems simple

DFlintstone

Valid point. (they are heater hoses, not cables). If you follow Highmileage's advice, you will not flush crud into the heater core. You can always come back and address flushing the heater core if you want. It's the heater valve it's-self that can brake while pulling the hoses off.

Remove that lower hose. Removing the E-fan is easy. Getting that clamp off is no fun, then getting the hose off is also no fun. Give her a go. Might not be as hard as mine was last time. (just awkward to reach, and the hose might be a little stuck on there).

Now with it free to drain anything, hook a garden hose to that inner heater hose going to the driver's side of the thermostat housing. Or remove the hose from the housing and figure a way to run a garden hose there.

I might just pull that lower hose, (with the filler cap off) and let her drain, then run a hose in at the top to flush the radiator. Then deal with the heater core separately, if need be.