Hi All,

I'm shure there is a sticky on this, but wondered about the 3.0L specifically - I see those t kits for back flushing, but don't really feel keen about cutting a $50 heater hose (these were like 40-50 bucks, and dealer only when I replaced them 4 years ago)

But, if the back flush is the best way to go, I'm all ears - I'd love to get better heat in the winter, and maybe this will run the van a little cooler - it runs past middle normal with the air on lately.

So, my question is - is it a good idea to back flush? or should I just use one of those cleaners, etc

opinions? - anyone back flush and found it worked wonders on the older areos? - it has never been done on this one, and it's an 89 - the coolant looks like it could use a flush - not horrible, but not clear/green either...

Thanks

 

The back flush will help with the heater core to a point. I assume it is the original heater core and being 20 years old, I bet there is alot of scale and crud buildup in it. Instead of spending $50 on a backflush kit, you might be better off buying and installing a new heater core which would run around $35. You mentioned that you already have new hoses so I would think you would be better off there.

As for the whole system, I would pick up a container of prestone cleaner, dump it in and run the system for a while drain, rinse, and fill.

I don't know which thread it was but Pablo had a great idea of using something (orange juice, or something like that) for cleaning out the system. He will probably pipe in about it shortly.

 

Yeah, I'd love to have the time to change the Heater Core out, but I guess I like doing things the easy way first, and seeing if it helps it at all - I was actually gonna pull both HC hoses, and do a gentle heater core flush that way with a garden hose on low pressure, going both directions

The heater works in the van, but of course, here in New England, we have very cold winters... I actually don't know if it ever really put out that much heat - did the older vans have a problem with heat in really cold weather?

I also have heard that to pull it is kind of a nightmare job, and you need mirrors, etc, short of pulling the whole dash out.

The only way I'd change it, is if it ever leaked - then I'd have no choice (well, except to block it off :-))

Peak makes a T kit with their cleaner for $15, but I have heard that in some cars, you can actually ruin stuff doing a back flush - or I guess, by the fact that you are going backwards, can unlodge some bigger stuff in the HC, etc...

I guess I don't want to create more of a problem than not doing it at all, is what I was wondering...

93, how is your 97 AWD? - Did they ever made that in a Shorty? I kinda like the shortys...

 

Just so you are aware, the flush fitting is a common failure point when left in the system. The plastic gets brittle and the part snaps. We have used these in three of my families vehicles, all three eventually failed, all did the same thing with the plastic part cracking. If you use the flush agent and make sure never to use tap water in the system, you shouldn't ever need to backflush the system.

 

I've done the flush thing before. It's more of a requirement on a system that has been neglected, where there are a lot of rusty crud. As long as you drain everything out from your flush, I don't think you will hurt anything.

If you're worried about the plastic T fitting disintegrating, you can replace it with a brass coupler after the flush. Most auto parts stores should have those.

 

yeap. I figured that the plastic would fail, due to the heat there - sounds like I'd be ok, just running a good flushing agent the normal way, and be done with it.

My thought also was, instead of cutting the hose, maybe just take it off, and run a temp hose from the WP to the T, and then from the T to it, and then just re-connect the hose back as normal when done - it's not something I'm gonna do every day -

I'm temped to try it, since it's never been done, but thanks for all those that chimed in on it - always good to hear the pitfalls, or the good things about stuff, etc...

 

The plastic tee flush fitting is really great to flush the cooling system, but take it off when your done. Some plastics will fail with heat, unless the plastic is virgin & you cannot be sure. After flushing drain the entire system, before re-filling, especially if you have harsh tapwater.

As for heat output, the single heater core system is not brilliant but adequate. It should be hot enough to feel like you want to move your hand from the airstream at the vents when working correctly. Mine takes about 10-20 mins in the -20c winter we get around here, to get full hot air from the system.

 

when I take it off, what do I replace it with? a brass coupling as was suggested? - I do like the idea of doing the back flush, but I don't want the plastic to leave me stranded...

which Heater hose should I use to do this? our tap water is ok, but we never drink it, if that helps :-) - I have a couple of gallons of distilled water too I could use - just want to do it right :-)

do you have a step by step on it? - thanks

Also, new thing - I hear air gurgling in the HC, but when the van is cold, I take the Rad Cap off, and it's full - so how can I burp the system, if it's already full? - wonder why there is air there that I can hear?

Also, on the mechanical door type heater levers, is the system using the heater core, regardless of the position of that slider? - or is there a vaccum switch in line as well?

Thanks to all on this...

 

Get two brass inline couplings & some 5/8 bore heater hose ($5). You can then connect up the heater & flush both ways & compare flow. The prestone flush will help too. I would follow their instruction first & then flush the HC in both directions to wash any loosened crud from the lines.
You can then install the flushing tee, open the drain tap & run the engine until the outflow is perfectly clear. Then drain the system & refill with 60% AF + Distilled water . I would change all suspect hoses and the thermostat while your at it.

 

AWD Shorty's were availible from '91-'95ish. After '95 it was only availible in the Long body form.

As for my AWD, it has been running great. Just last week we went on a 800mi trip. I averaged 18.9 mpg, which I wish was more, but oh well, the trade off of fuel economy for room for the wife and three kids, all their stuff (and the kitchen sink) plus having a/c running in the front and back, and with the stability of AWD, it is hard to be beat.

 

bought a backflush kit years ago for my 4L. never installed it after seeing the thin weak T fitting, didn't want a major overheating failure miles from nowhere up a logging road or out in the middle of the E. Wa. desert.

i just add a bottle of Prestone radiator flush.
run for 1/2 hour at temp.
take out the thermostat, pull one of the hoses to the rear and front heaters and remove one end of the bottom radiator hose

i then blow out the system with a garden hose and nozzle only turned partially on. heater cores are only rated to handle 30 psi max.
nozzle into heater hoses flushes out the cores.

nozzle at full pressure into thermostat opening blows out coolant passages in engine which flush fitting will never get to.

best to remove radiator to do a complete flush on it as the core ends are where most crud collects in a mineralization deposit form. use a long commercial plumbers brush in thru hose holes to rod the ends, hose flush thru both sides. blow water thru from the backside of the radiator to blast all those sticky little road kill bugs out of the fins.

use compressed air to blow out much of the tap water.

 

Cliff - didn't you have an 89 at one time? - I only have the one heater core on my 3.0L 89...

seems like all I can find around here are the T back flush kits, and not just the stand alone flush product - I remember about not using a lot of pressure for the HC - I was actually gonna pull both hoses and run low pressure hose there....

I get a film on the top of my Rad fill - esp when it's really cold, you can see it, I usually drain and reload every 2-3 years, but I know it's never really been flushed with an agent... got to get that done before the winter comes...

Thanks to all - I'll see what I end up with... not sure I'm gonna pull the radiator, and get that into it, unless this is why the van is running a little hotter lately than normal - it was always at a 1/3rd on the gauge, and lately, I see it staying around the middle... would like it to be a little cooler, esp when air is on, etc...

BTW - a bit off topic - can I put a newer 3G Alt in the 3.0L without having to rewire anything? - thanks

 

is the film on top of the coolant greasy or oilly? not good.

most coolants will develop a slight film from the chemicals used for coolant system corrosion and water pump seal lube protection

i like to use a can of Prestone or Gunk coolant restorer and water pump lube every fall as and additive.

96 was my first and only Love Van.

only certain way to measure coolant temp is with a thermometer.

 

it's only a film looking thing when it's really cold outside - like below zero it's not oily per se, but it's like when my mom used to make homemade pudding, and you'd let it sit in the fridge, and it would have that skin not quite as jelly as that, but similar... - if I opened it right now, (90+ degrees) it would look fine, like normal - hope it's nothing major, but the van isn't overheating, and nothing but oil in the Oil Pan :-)

BUT - one other thing I noticed last couple of years, when it's raining outside, and like in the 50's-70's - you can smell a little bit of antifreeze sometimes around the passinger side, but outside the van - I see no leaks (heater hoses are right there, and they are fine, etc... it's strange... only when it's raining do you smell it... why? - am I crazy?

Still love my Van, and I'm the original owner of 20 years! - hope to have her another 20, and thanks to all of you, I might just get there! - not too many 89's like mine, unless they are CA or Fla cars...

 

Use the flushing tee for conveniance but remove it after you are done. I never leave mine installed ,plastic cracks sooner or later!

Sounds like you have the start of a leak, check around the heater hose push-in connections ( does yours have the AC heater bypass valve ) plastic looking block with 4 hose connections & a bell shaped butterfly vacuum valve, I had one fail recently.

Any bubbles in the AFC with rad cap off at idle?