Coolant Leak

My '98 4.0 has produced a very small leak, which seems to be coming from the radiator (bottom passenger side).

The leak is not very noticeable, I probably wouldn't have noticed if I wasn't accustomed to checking under my Jeep on a daily basis!

Currently, the drops on the ground only accumulate to about the size of a nickle, & there's a few drops dangling from the bumper.

I had my coolant system serviced a few months ago & it's definitely coming from the radiator! Could this be the O-ring or some type of seal?

Sounds like they didnt screw back the drain plug properly.

When you check the level in the expansion tank ( a/f cold) what is the level??

All kinds of possibilities here. It is an old rad so could be pin holes in the tubes from electrolysis or the seam for the upper or lower tank is leaking ( not sure if this is a metal or plastic tanks). The plastic seem to give more problems.

Leaks in the rad can be hard to see because of all the shrouds and the a/c condensor.

You've no doubt checked the upper and lower hose clamps already and what ZJ suggested above.

Check the weep hole on the water pump. The a/f might be running across the frame to the bumper???

JD

The leak appears alittle left of the drain plug (maybe 3 0r 4 inches).

The level in the expansion tank is at the add mark! I had a post on here a while back about this because there was a contradiction in the Haynes manual, it states to maintain the level at the "add" mark & in another sentence it says it should be at the "full" mark? However, it has been at the "add" level since I had the coolant changed.

I quickly glanced over the hoses & they seem OK (top & bottom), I will check them more thoroughly!

I tried checking the weep hole & I didn't notice any drips in that area. I will check it again however!

Yesterday was one of the coldest days we've had this winter. Damn weather!!!

After a taking a 2nd look, my hoses & water pump are OK!

I did notice however, that there are 2 rubber type bushings on the bottom of each end of the radiator. Both rubber pieces appear to have cracks in them, but the one on the passenger side has coolant on it.

The leak seems to be coming from or through this rubber piece!

the coolant level should be at the ADD mark when engine is completely cold, and FULL mark when engine is hot.

it does sounds like the plastic side take may have developed a pin hole like JD said. might try some alumiseal or barsleak and such it might seal the hole, believe me don't let it go it will cause more problem, I had a similar problem where I added coolant about once or twice a week, couldn't figure out where it was going, had notice a couple small puddles of coolant but never could find out where they were leaking from. well I let it go for about 5 months to my regret this also caused my jeep to overheat - I didn't think iit was overheating (215-245 degrees) I thought it was just gettting hott b/c summer was coming and it was warner out, well on my way back from Pittsbugh (80 miles from where I live) my engine went (bent crankshaft, snapped timing chain, shattered timing cover, hole in block), stuck on the side of the road, $235 to get towed back to the house. well I put a new engine in, and then about a month or so later my radiator blew (10" long crank in the tank), Cost me $175 for a new radiator and afterwards I noticed my engine was not getting hot (after idling for almost an hour in 88 degree summer sun I was idling at 175 degrees), well I came to the conclusion that the jeep was overheating and this caused my engine to go also cause my radiator to blow. Hope my story helps you and keeps you from encoutering any of the problem that I have delt with.

Also I thought my overheating problem was caused by me getting the jeep stuck in a giant puddle - had it burried of the bumper. I hit the puddle to fast and got water in the combustion chamber and such, then after this when I got it running again the next day, thats when I noticed the engine was getting hotter and at the time thought it was because of what happened but then thought maybe it was because it's getting warmer out, well I have now came to see that the jeep was overheating the whole time I had it (since febuary 04), b/c now it is in the low 30's here in PA and my jeep is staying below 155 degree mark more toward 140.

If the leak is at the bottom of my radiator near the rubber piece, do you think it would be sufficient enough to use alumiseal around the area w/out removing the radiator?

Also, I forget off hand who responded to my post a while back, but they stated that the coolant should always remain at the "add" level, unless it overheats then bringing the fluid up to or past the "full" mark!

My coolant never moves up past the "Add" level, even after driving long distances.

If the leak is at the bottom of my radiator near the rubber piece, do you think it would be sufficient enough to use alumiseal around the area w/out removing the radiator?

The alumiseal and barsleak are additives that you put into the antifreeze. They disolve and work their way into the small passages where the a/f has a hard time getting thru. It is best when one of those passages happens to be a leak but they can finish plugging a coroded tube in the rad or other passage too.

Sounds to me like the rubber rad mount is ready for replacement with a new rad. For the price that dksob81 has mentioned, it isn't worth the hastle to try and fix the old one.

Replace the rad cap at the same time.


Also, I forget off hand who responded to my post a while back, but they stated that the coolant should always remain at the "add" level, unless it overheats then bringing the fluid up to or past the "full" mark! My coolant never moves up past the "Add" level, even after driving long distances.

The add mark is the minimum level when cold and the full mark is the maximum level when hot.

If it is not moving above the add mark when hot, then the coolant level in the rad is low. The tank is there to recieve the expanding a/f when the system is hot. If the system is low, then all there is only air in the top of the rad to be moved out. When it cools off, air comes in where the leak is and the level drops even further.


JD

I replaced my Rad cap when I had my fluid changed, I'll try the alumiseal and/or barsleak as a short time fix while I look into getting a new Rad.

I appreciate the info.

Well, I had a new radiator installed today & I know longer have any leaks coming from this area. The shop charged me a total of $315 (including installation), I opted for the metal rad.

I now I have to replace my recovery bottle (no big deal) because it's always producing a/f around the cap & bolts!

Hopefully this will be enough to get me through this winter!

I had a new rad installed in Dec. '04 after reading the replies from this post. Less than a year later, this new rad is now leaking just like the old one was!

I am positive that it is not my water pump or petcock!

The coolant appears to leak only after the vehicle has been turned off. The leak is not major, & I touch up the recovery bottle maybe once a month.

The level in the radiator is always good when cold!

What the hell is going on here?

I am having kinda the same issue, I think I might have a slight leak (very slow, bout the same as yours) and it appears to be coming from the T-Stat housing.

I am having kinda the same issue, I think I might have a slight leak (very slow, bout the same as yours) and it appears to be coming from the T-Stat housing.

Same happened to me on my '95. Had the rad replaced at an independant shop with an aftermarket rad. About 6 months later had a leak again. They replaced the rad under warranty, has been fine since.

My leak has picked up recently! When I turn the Jeep off, the coolant drips off of the front bumper forming a nice size puddle! It does not do this all of the time.

My rad is less than a year old, & I am tempted to use one of those sealer products available at part stores. I hear these products can block the heater core as well! What kind of experience have you guys had with these products?