Coolant leaks: what are the odds?

[TRevs]

2006 LJ, stock engine and cooling system, 87k miles.

A month ago I had a leak from the radiator, replaced it (along with a new Motorrad radiator cap) a week ago and all good until yesterday and I found another puddle underneath. Looks to be coming from the block under the crank pulley, probably a water pump.

So two failures in different areas separated by about 100 miles of driving.

Which is more likely?

A) it’s just coincidence; they are 20 year old parts and are expected to fail. This is why it is recommended to change all the cooling system parts at the same time.

Or,

B) it probably has an obstruction somewhere causing excessive system pressure and I should get a tool to measure the operating pressure or something else will fail next.

 

[JKP]

I just had a radiator leak in my 06. Replaced the rad, hoses, clamps. Had just put in all new coolant and burped it. No leaks. Put the radiator cap on and the water pump immediately blew... My pump, rad, hoses were about 10 yrs old. 290K on the Jeep.

Yep, water pump. 20 yr old seals are done.

 

[TRevs]

Yeah maybe the old radiator cap wasn’t quite holding pressure but the new one is and that just pushed the water pump over the edge

 

[That'll Buff]

Yeah maybe the old radiator cap wasn’t quite holding pressure but the new one is and that just pushed the water pump over the edge

My friend and I had very similar experiences. I realized I had a bad cap in moab and a few days after replacing it I noticed a coolant spraying against my hood that revealed a small crack in the radiator tank.

My friend ignored more warning signs but eventually changed his cap. Not long after his radiator blew a chunk out and his engine overheated pretty bad. He thinks it might have already had issues and the new cap allowed proper pressure and the radiator finally gave way. Not saying I know for sure that's what caused it, but it is the through line for both of us.

 

[KennethS]

B) it probably has an obstruction somewhere causing excessive system pressure and I should get a tool to measure the operating pressure or something else will fail next.

No.

 

[Zorba]

That is one remarkable thing about these TJs - the entire cooling system fails pretty much all at the same time. That includes the fan clutch, change it too.

 

[Danarch]

That is one reason I replaced most of my coolant system. Did everything but the radiator since it was still OEM. Decided to keep the OEM radiator.

 

[KennethS]

That is one reason I replaced most of my coolant system. Did everything but the radiator since it was still OEM. Decided to keep the OEM radiator.

They are great until they explode. Mine split the top tank from the hose nipple to the cap while doing 70 MPH on the interstate. No warning signs, just blew up one afternoon I guess because it was old.

 

[rasband]

That is one remarkable thing about these TJs - the entire cooling system fails pretty much all at the same time. That includes the fan clutch, change it too.

This was what I came to say and did it all around 80,000 miles.

 

[TRevs]

That is one remarkable thing about these TJs - the entire cooling system fails pretty much all at the same time. That includes the fan clutch, change it too.

Any brand recommended for a fan clutch? I’m not seeing any brands I’m familiar with.

 

[JKP]

Hayden, althuogh I'm running the Advance auto one that appears to be a reboxed Hayden to get the lifetime warranty.

 

[rasband]

+1 on the Hayden.

 

[TheBoogieman]

That is one remarkable thing about these TJs - the entire cooling system fails pretty much all at the same time. That includes the fan clutch, change it too.

Did you just jinx my original cooling system after 23 years in one post? Thank God my mom isn't alive to get you.

 

[Zorba]

Any brand recommended for a fan clutch? I’m not seeing any brands I’m familiar with.

I'm running a Hayden 2771. People here either love it (I do), or hate it (too noisy). Pick your poison.

 

[TheBoogieman]

I'm running a Hayden 2771. People here either love it (I do), or hate it (too noisy). Pick your poison.

I'm not sure of the exact number of my Hayden fan clutch, but I KNOW my wife makes way more noise. Prayers for her and tomorrow's Cancer results. I don't handle stress well.

 

[Zorba]

I'm not sure of the exact number of my Hayden fan clutch, but I KNOW my wife makes way more noise. Prayers for her and tomorrow's Cancer results. I don't handle stress well.

Goddess Bless you both - prayers going out!

 

[TheBoogieman]

Goddess Bless you both - prayers going out!

Thank you so much!

 

[TRevs]

I found a few threads on here that said the hayden can have problems staying in the locked position, and the USMW was better. They’re both favs on RockAuto and about the same price.

Note that I think about it, I haven’t noticed that roaring fan noise with a cold engine. My current one has probably failed locked and does need to be replaced after all. Especially before colder weather.

 

[JKP]

If your clutch was locked up, it would be roaring all the time, and you would actually feel a loss in power.

 

[freedom_in_4low]

I found a few threads on here that said the hayden can have problems staying in the locked position, and the USMW was better. They’re both favs on RockAuto and about the same price.

Note that I think about it, I haven’t noticed that roaring fan noise with a cold engine. My current one has probably failed locked and does need to be replaced after all. Especially before colder weather.

one of them was probably mine.

I spent a weekend in the rockies and the Hayden was roaring almost the entire time...the last day started at 13,000', below freezing. Fan was on from startup, through engine braking down thousands of feet with no load, temp wasn't even high enough to open the thermostat most of the time so there was no way the air coming off the radiator was the 170F it's supposed to take to engage the fan clutch. I swapped it for the USMW as soon as I got home. I stil want to go electric but it at least works the way a mechanical fan is supposed to.