Update: Coolant issue

[Naturalhoosier]

So I started the thread below for assistance w/a coolant issue.

Help me diagnose this coolant issue (long)

This is a quick synopsis. I've changed the water pump/thermostat/radiator and various hoses because of the leaks I had.

Last night, I finished up installing the radiator and I burped the system. I let it run for 20-30 mins then I took it out for another 20-30 min drive. The heat was working fine, everything was perfect!!!

I get up this morning to run an errand and I start it up and the "Coolant Low" light was on. I open the hood and the overflow tank was at the low mark. My first thought is OK...the radiator just needed that extra coolant because I didn't burp it long enough.

I go out this afternoon and fill the coolant overflow and start it up. After 10 mins, I can see bubbles rising in the over flow tank. Just a small bubble every couple of secs. There are still no visible leaks.

The oil and tranny fluid both look OK. Neither look like they have water in them. I guess my next step is to 'borrow' a pressure tester from Autozone's 'Loan-a-tool' program that they have.

Are there any other suggestions? There is a coolant smell on the outside of the rig, but the exhaust isn't white and fluffy and there is zero trace of it when you are in the cab, heat on or off. I'm completely perplexed.

[QuadraTokn]

is there a puddle on the ground?

[Naturalhoosier]

Originally Posted by quadratokn

is there a puddle on the ground?

No. There is no coolant leaking anywhere on the outside of the engine.

[-Joe-]

Whats the concern then?

Upon first starting I can see a bubble every now and then in the over flow tank..

Probably just didnt give it time to circulate the coolant and just needed to top it off the next day.

[Chloetar]

Make sure your hose clamps are fully seated and tightened properly. About a month back I changed the hoses and had the smell but no ground puddles. Every few days, the bottle was low. I knew it was the lower hose because I saw it seeping, got under it and tightened the clamp a little more for the cure.

You can't get an external smell without some type of leak. Good Luck.

[greasefingers]

Just replace the radiator cap. It is probably bad and relieving the pressure at a lower pressure than it was designed to. It should be a something like a 16 psi cap. The engine can also over-heat with a bad cap. The 16 lb pressure raises the boiling point of the solution (coolant). This is usually evident by an overflow reservoir that is always filled up to the brim.

[Turbonut]

If you have access to a pressure tester, throw it on the Jeep when cold and let it sit @ 18lbs for quite a while to see if any leaks.

As you just did the water pump, make certain you retightened the hose clamps when the Jeep is hot, and the hoses are more pliable.

[Naturalhoosier]

Ok here's what's up. It appears that the new gasket isn't holding in the coolant on the bottom of the water pump and that's where the leak is stemming from.

I plan on replacing the gasket this weekend. Is it possible to use a gasket other then the paper one that is supplied w/the water pump? What about RTV or Hondabond? I am skittish to use these type of sealants w/the fear that they might clog the heater core. Thoughts?

[driabyor]

I use Indian Head Cement... at least the gasket wont slip

[greasefingers]

OK this is what I do with all water pumps. The two mating surfaces have to be parallel!! Take as much time as necessary to accomplish this. After scraping and such, I use a gasoline soaked sponge with Scotch-brite (the green scratchy stuff) to remove any residual paper or silicone remnants.

Then I coat both sides of the paper gasket with Permatex sealant. I only use the type made for water pumps. It’s in a gray tube.

Then I use a torque wrench. The torque is 30 ft-lbs for the v8 engines made between 1993 to 1996. This is important. I sometimes even torque it twice (like first at 20 ft-lbs and then again to 30 ft-lbs). Tighten them in a star-like fashion (similar to the pattern of torqueing the lugs nuts on a wheel)

Let it sit for a couple of hours, if you can, before filling with coolant.

These guidelines should help minimize post-leaks.

[Turbonut]

Originally Posted by Naturalhoosier

Ok here's what's up. It appears that the new gasket isn't holding in the coolant on the bottom of the water pump and that's where the leak is stemming from.
Thoughts?

As everything has been apart and a new water pump, make absolutely certain that it is in fact leaking out the bottom of the pump through the gasket, and not the O ring, bypass hose, or the pump weep hole. Finding the origin of a leak is difficult as the fuild isn't readily seen. Put some talcum powder all over the top, sides, and front of the pump to be certain of the leaking area. Don't want to be ripping the pump out if it's possibly leaking elsewhere.

[Naturalhoosier]

Thanks again for the tips guys!!!!! I will let you know the outcome when I do it this weekend. Thanks again!!!!

[Naturalhoosier]

Originally Posted by greasefingers

.

Then I coat both sides of the paper gasket with Permatex sealant. I only use the type made for water pumps. It’s in a gray tube.

So do you just kind of rub it in instead of using a bead as the directions say to do? I just want to make sure I'm doing it correctly!

[yrubugn]

I havealways used permatex high-tack on paper gaskets. With clean mating surfaces as mentioned above have never had a leak.

You can brush it on and let it sit a minute to adhere so it doesn't move when installing.

Good luck...

[CajunWon]

Originally Posted by Naturalhoosier

So do you just kind of rub it in instead of using a bead as the directions say to do? I just want to make sure I'm doing it correctly!

Use a new gasket as the permatex may not adhere as well to one soaked in coolant. Apply a bead, then spread it evenly/flat with finger/brush -whatever. If it oozes out the side then you used too much. I apply to pump, then place gasket, then apply to engine, then install. I also wash & dry mating surfaces to ensure adhesion, since you don't want to do it twice.