Write-Up: Radiator Replacement

Mine did the same thing. It soaked the entire front moulding with trans fluid. Solution: unscrew the trans line, clean off the fitting, reapply Tephlon (I use the liquid tube type) and re-tighten. Applied about 10% more torque the 2nd time. So far no leaks after 3 months.

Thanks AA!

It's been about 3 weeks with the new radiator and that was the first instance, so I assume it finally got past the teflon and then started leaking...

I'll remove the bottom cover and should be able to reach up and clean parts & such.

Radiator lines are flare nut fittings, NOT pipe threads. You should not use anything on the threads, a flare nut seals by pressing the tubing flare on the base/tapered part of the fitting.

okay, two sides...

so NO teflon (or at least a tape type)???

I can see how AA's doesn't leak if he used a liquid sealant...

deekster_caddy wrote:

Radiator lines are flare nut fittings, NOT pipe threads. You should not use anything on the threads, a flare nut seals by pressing the tubing flare on the base/tapered part of the fitting.

Don't to anything to flare fittings except clean them and lube them... I've had mine apart once for the aux tranny cooler and once for the POS plastic radiator tanks, and no leaks whatsoever.

(Seriously - NObody else has any trouble getting the new radiator aligned to the mounts at that sloping angle??)

Natesriv wrote:

okay, two sides...

so NO teflon (or at least a tape type)???

I can see how AA's doesn't leak if he used a liquid sealant...

With a flare nut, if the seat and flare aren't squeezed together, it can leak out by the threads, or right around the pipe/nut. There is clearance there too, and if there is a pressurized leak it can and will come out anywhere it can. It's essentially two sealing surfaces, the flared pipe to the female receiving fitting seat, and the flare nut to the back of the flare on the pipe. The threads are not tapered, and not sealable. It's possible if the fitting isn't tight enough but was somewhat tight, that fluid was leaking past the flare seat and down the threads, but the flare nut to pipe/flare part of the seal was holding. But if the base can leak, the nut will eventually leak too, so sealing the threads is only going to hide your leak until another time. The key is making sure the pipe is straight and the threads are not crossed. Personally I hate flare nuts because I tend to overtighten them and round out the nut, requiring vice grips next time it comes apart. I think the newer design with the O-ring is a massive improvement.

Okay, I got in it again yesterday and took the nut off. Cleaned the threads and the inner threads on radiator (as best I could).. I DID apply a small amount of thread sealent to the threads...this time a thin liquid instead of tape... and I then threaded it back and tightened it good...I feel any harder and I'll strip something...but I turned it pretty darn hard.

I then hosed off the spilt fluid and let it dry... Then I put a paper towel under the lower nut and went for a drive today. About 20 miles of mixed driving. Got home, looked at towel and it is wet with fluid, but not soaked.

Since that towel sat overnight, I wonder if it was just soaking up the watery/transmission fluid that was left over from the hose washing...

If it's still leaking then I'll take it off again, and NOT put anything on it, I'll clean the threads and put it back together and tighten it good again..

but besides that...what else can I do? I threads in, doesn't feel stripped but the nut doesn't go all the way in (never did I think)....

Wait a few days and see if it's actually still leaking. It may not be.

At this point, you need to think about protecting the radiator. If you over-tighten, it could damage the fittings, and that's the last thing you want to do. The way these work, when they get tight, they don't want to be tightened much more.

If we assume the new radiator fittings are in good shape (probably are), that leaves the line nut as the culprit. Imo, you can fairly easily cut the line and install a new nut and re-flare the line. That's what I'd do if you're still having a problem in 3 days time.

well SHIT!

Guys, guess what? When I bought this used replacement radiator, they plugged all the openings...INCLUDING the little overflow tube outlet.

Today my Bro-In-Law and I were looking at it...and realized that little opening was plugged, Removed the plug and all is better...

BUT...we also saw oil in the coolant...unsure if it's motor oil or tranny fluid (since that tranny fluid cooler is on the passenger side)

So....I'm unsure WTF to do... right now I see no indication that I blew a head gasket..car drives fine, no smoke or steam or bubbles in coolant. No foam on oil cap.... we're thinking the plugged outlet may have overpressurized the internals and made the tranny fluid leak out...an internal crack which is now closed since the coolant system now works right..

I'm going to drive it and check every day for leaks, bubbles, and other indicators for a gasket faiure or tranny leak


SH_T!!! I never thought to check that little tube!!

Took another look this a.m. ...a better look

Appears the entire inner surface of the radiator (at least as far as my finger can reach) is coated in a blick oily film...it's not reddish, but certainly is sludgy..not like motor oil

What could it be...motor oil? Tranny fluid?

AND WTF do I do with it now?

I know I have to drain it again, and new coolant, but it will need a major flush to get all that goo off the innards...can it even be done with a flush?

I'm not driving the Riv again until I get a new radiator...not a USED one... I think my not removing that plug I may have overpressurized it and damaged it internally...

THIS SUCKS!

okay, bought some radiator flush which says it removes sludge online. Will wait for it to arrive. Then I'll flush the entire system and refill...hopefully the plugged outlet was the problem...

until then, she sits in the driveway until I can flush her. I'll redo the tranny line again, it appers to still be leaking, but now I'm curious is the leak was always related to the blocked outlet and the whole sytem being overpressurized...

anyone??

I would guess that is transmission fluid. Transmission cooler leaks are fairly common in radiators. Either that or it's oil from the intake manifold. Having the radiator pressure tested should identify the trans cooler's status. Having the whole cooling system pressure tested should help locate other leaks (engine/LIM gaksets etc).

You need to figure out where it is coming from. Adding a cleaning agent and flushing the coolant will not do any good unless you have found/stopped the leak first.

well, it's a used radiator and i don't see any way to check internals for leaks...
I think I'm going to just get a NEW radiator, flush the system before I install it thorugly and put the new one in.

Hey, to get enough flow into heater core, should I remove thermostat for the flush?

Coolant is always fully flowing through the heater core, even before the thermostat opens. You want to warm it up enough for coolant to flow through the thermostat as well. It also depends on the type of flush, so follow the instructions that come with it.

another thought, would it be an option to bypass the tranny cooler lines and just install a tranny oil cooler radiator itself...mount it in front of the a/c radiator?

You can install an external cooler. They work much better than the internal cooler. The only downside is running the transmission fluid too cold in the winter. Otherwise it will be fine.

looking at the posted link...it appeared in diagram that it still went through the radiator...but I haven't fully looked.

I think i'll stay OEM if I can...just not looking forward to redoing the radiator again... but she is 16 years old

I run mine in series with the radiator, but that's because it doesn't leak! You can bypass the radiator if you want. I installed a thermostat on the transmission line to only flow to the external cooler above 180º.

It should be run in series with the radiator's trans cooler in a permanent installation. But since you need to eliminate a possible oil into coolant leak, you could try bypassing the radiator completely and leave it that way until next winter. You will also find out quickly if you are leaking antifreeze out of the trans cooler fittings!

There is also a UV dye you can add to your coolant.

BLAH! So much work...if I'd only found that little plug!

And it's rainy here all week, so I'm basically just waiting...

Driving my Si, and that makes me appreciate the almost silent super smooth ride the Riv has!

UPDATE:

Went an bought a new radiator at Advance Auto for $198 with tax. Could have had one cheaper ($155 before tax) but that was about 20 miles away... and $4 gas kinda equals it out

SO....put it in...seems to work fine. I flushed the old radiator and the fluid was mostly green...it seems just the internals of the radiator were oil soaked...may have been tranny fluid...

BUT!!! I sorta pressure tested the tranny section and it sure seemed fine...

OH, I had cross threaded the lower tranny connection and that's why it leaked... so a replacment had to be done...

I do recommend when installing a radiator to disconnect both the small clamps that hold the lines to the frame... that way you can maneuver them to screw in the connectors to the radiator by hand... Lower one went in fine,, went for a long drive, no leak...problem solved.

So bascially I wasted $100 on an old radiator & fluid... as my Brother-in-Law says.."It's only money, you can always make more"

Thanks for the update. Glad to see you are back in business!

yes you can always make more money, but the feds frown upon that LOL

why? they do it in china all the time!!!