Coolant Leak

[A2B in a TLC]

Hi Gang,

I just returned from a great trip to Campbell River. Met a BJ70 owner named Peter at the camp site and compared notes. I love hearing owners tell me stories like his. Its an '85 he's had since 1992. About 350,000 kms (I think). Other than the fact that he spent a bundle many years back on cutting out the rust, he has run his BJ70 for 13+ years with few problems. Just the usual exhaust, radiator, etc. stuff. He didn't know about IH8MUD. Hope he joins.

Anyway, I packed up camp this morning and drove the BJ74 to the nearest gas station for a coffee. Low and behold, I had about a six inch diameter coolant leak under my truck when I pulled out. I popped the hood to check, engine running. Yep, leaking. It seemed to be dropping down from the fan shroud. But then I noticed that there was also coolant on top of the fan shroud, where the hose from the overflow reservoir runs. No apparent holes in the hose. (I had a new water pump installed a few weeks back, so that's not it.)

I drove a while to let the turbo heat up the motor. Checked again, coolant full, no more leaking.

Could a cold engine, thermostat not yet open, cause a leak that would go away once the vehicle is warmed up? And if so, where is it leaking from?

I drove 2 hours back to Duke Point, coolant still "full". Its not leaking now.

Anyone got any ideas?

Thanks,

Bruce

 

[silvercrusher]

i would bet that since the fan pulls air through the shroud and it is inside the shroud that you have a pin hole in your rad somewhere. Mine just did the same it lasted about a year before i replaced it. Just started seeing rust around the t stat housing and the front of the head a traced it forward. Look up in the shroud and see if your rad looks all rotten .

mine leaked so little that i only had to top up every month or so until it really got bad. Cost me $350 for a 4 pass recore in duncan.

 

[A2B in a TLC]

Thanks SilverCrusher,

Did the $350 include re & re?

My rad looks mint. No rust in the coolant, etc.

The thing is, I have just 120K kms on the rig. But its 17+ years old. Seals, hoses, etc. age even with no mileage.

B

 

[crushers]

i really wouldn't worry about it, the truck probably just burped... you mentioned a new water pump recently so that is very possible...

 

[A2B in a TLC]

Hi Wayne,

The water pump does not appear to be the problem. And I couldn't find "Burp" in the cooling system section for trouble shooting.

Could the closed thermostat cause? But where would the back pressure normally cause a leak?

Thanks,

B

 

[crushers]

no the water pump wouldn't be leaking, what can happen is an air bubble is trapped in the coolant system after installing the water pump or any other opening of the system and the newer 13BT, 3B, 2LT can have this occur, the trapped air suddenly lets go and "burp"...
keep an eye on it but i wouldn't loose any sleep over it...