Topic: Coolant system- dark red liquid

[cyberdyke]

Hey,

This is my first "help" post here -  I need to ask the list some questions, but first let me give you the back story:

A couple of years ago my radiator, apparently like all stock TJ radiators, sprung a leak.  As the engine got hot it sort of sealed its self, so I just watched it for awhile until I had a chance to fix it.  I bought a radiator from RadiatorBarn.com and it sat in the box in the house for a couple of years until I got ready to fix it.
Last Jan 2011 I replaced the leaking radiator with the new one.  In doing that I had some problems with getting the idle pulley tight enough after also replacing the drive belt and my rig was out of commission for several weeks.  After finally getting the snafu with the drive belt fixed I drove my rig and suddenly there is a gusher coming out of the bottom of the new radiator.  I put some stop leak in it and waited until the weather improved and I had some $ to again replace it.
I did some reading and found out that everyone suggested that I replace everything that might have had the stop leak in it.  A

Around the first of august I did a radiator drain and clean and then removed the radiator.  But before I could do much else the weather turned.  In the mean time I did take the garden hose and sprayed off the build up of gunk on the as much of the engine as I could reach.  Last week I began to do the replacing, water pump, heater hoses, radiator hoses, thermostat, and finally the new radiator.  I was pouring the coolant back in very slowly so the air could escape when I had gotten about a gallon and 1/2 in and there was dark liquid puddling under the rig.  :(  Seemed to be coming from the bottom of the therm housing.  I got out both of my torque wrenches and re-tightened the bolts to 15lbs, according to my FSM - but the liquid level is low now and I haven't put anymore in.

Here's the questions:
The liquid is very dark red coolant - did I screw the pouch by not having liquid in her for over a month?

If that is OK - should I drain the coolant out and put water in until she runs clear and then put the coolant back.

Why would the therm housing be leaking?

thanks

J

[sharpxmen]

did you use red coolant before? there is a block drain plug which you should take out and run water thru everything, the red and green coolant should not be mixed. the thermostat housing can leak due to a bad gasket, cracked or even at the hose neck if it's corroded,  i would take it out and reseal with rtv and a new gasket - it sounds like you replaced the thermostat already, did you use rtv (silicone) when you did that? also, did you clean the inside of the hose (if you took that off the thermostat housing), it builds up deposits so that can leak as well.

another note, the red coolant is not very dark, it's light red in color and translucid as opposed to the electric opaque green of the other kind, the automatic transmission fluid is dark red, is your transmission auto or manual?

[chardrc]

could he have a transmission cooler leak form a trany cooler in radiator type cooler set up. wouldn't seem too far fetched since it sounds like the new radiator leaked when first installed (assuming he has an auto trans as sharp asked).

[cyberdyke]

I didn't use red coolant.

Before I began taking the coolant system a part she ran clean I've never seen any "rust" or any color other than green or clean water before.

I took off the therm housing and took a look at it and it didn't seem to be corroded or cracked.

Please explain: RTV silicone goes exactly where?  Front to "stick" it to the therm housing?  Back to help stick to therm?  Or both?

I'm going to drain the coolant out and flush with water to get the rust that has sprung up since I started this job.  Question: if I run water in through the top of the radiator and leave the radiator drain open - do I have to have the car running to cycle the water through the coolant system?

thanks!

[JohnnyO]

I'm going to drain the coolant out and flush with water to get the rust that has sprung up since I started this job.  Question: if I run water in through the top of the radiator and leave the radiator drain open - do I have to have the car running to cycle the water through the coolant system?

Sounds like the red fluid is transmission fluid, if your Jeep is an automatic the radiator will have a transmission cooler built in to it.  A new radiator shouldn't leak, hopefully the leak is coming from one of the transmission cooler lines.
I would drain the radiator by pulling off the bottom hose (it's faster that way), fill it with distilled water and a bottle of Prestone Super Flush (this gets the rust), and drive it around for a few miles with the heater on Hot so you flush out the whole system.  Drain it, fill it at least once more with plain water, drive it around with the heater on again, and drain it.  Once it drains out reasonably clean, add one-half the capacity with antifreeze, start it up with the heater on, and fill it to the top with more distilled water.
It is actually bad to store vehicles without coolant in them because the block, heads, and radiator will rust.

[sharpxmen]

Please explain: RTV silicone goes exactly where?  Front to "stick" it to the therm housing?  Back to help stick to therm?  Or both?

rtv on both sides of the gasket that goes between the thermostat housing and the cyl head

do you have auto or manual transmission ?

[Jeffy]

I replied to her before sending her here so I'll reiterate.  I speculated the red is rust.  Without any coolant in the engine for a while, rust had formed inside the block.

I also told her to take the thermostat housing back off and check the gasket surface but she said she had scraped it.  I also recommended that she use some Permetex Blue or RTV Black on the gasket.  A light coating on both sides.  Spread it on with your fingers.

[sharpxmen]

I replied to her before sending her here so I'll reiterate.  I speculated the red is rust.  Without any coolant in the engine for a while, rust had formed inside the block.

I also told her to take the thermostat housing back off and check the gasket surface but she said she had scraped it.  I also recommended that she use some Permetex Blue or RTV Black on the gasket.  A light coating on both sides.  Spread it on with your fingers.

then should be rust, i can tell that pretty easily by looking at rusty water so i assumed that's not it - maybe a picture or 2 can clarify the "mysterious" liquid