Coolant woes

[DaveB]

My daughters 97 Cherokee has been leaving coolant puddles on the driveway for a while and I decided to try and fix it yesterday. I found that the weep hole on the water pump was leaking so I took the pump out. While the fans and such were out of the way I noticed that the radiator was also leaking. My daughter is a single mom with limited funds so I tried some used parts. My son had found a nearly new pump at one of the junk yards so I put that pump on. We also had an older radiator from my son's Comanche that we swapped out when we put the stroker in his Jeep. It had never leaked before but had sat for a while. I buttoned it all back up and started it. It seemed to be fine for a while then I noticed the pump was leaking, and the radiator was too. I took it all out again and gave up for the day. I ended up wasting most of my Saturday. I have been thinking since that maybe her Jeep might have a head gasket leak that is building up pressure ? I didn't see any of the tell tale signs of a leak, the hoses weren't hard, no bubbling in the coolant while it was running and the oil looks good. I don't want to order a new radiator and pump only to find it leaks again. I'm going to try a compression test and see if that shows anything. Any other tests I should run before ordering parts ??????

 

[Greg]

How cheap and questionable are you OK with? 😁

I had a similar problem on a new radiator that leaked which I had installed installed in a Jeep. I just ran a 1/2 can of Stop Leak through the system briefly with water, then flushed it out after a couple of start up and cool down cycles. That fixed ended up lasting and took care of my problem without much more additional effort.

I don't like the idea of keeping Stop Leak in the cooling system permanently, I feel like it could eventually start plugging cooling passages, heater core, etc.

The proper way to do it would be to pressurize the system and see if you can identify exactly where the leak is coming from and repair it correctly. You might be able to rent a radiator pressure kit a local part stores.

 

[I Lean]

There are test kits for combustion gases in the coolant, that might help diagnose a potential head gasket issue.

 

[DaveB]

I have one of the block test kits and could also try the pressure test but I took the pump and radiator out making the tests difficult to do.

 

[Kevin B.]

Any other tests I should run before ordering parts ??????

With used parts in the equation and no other signs of a failed head gasket (running rough, overheating, oil in the coolant or vise versa?), I think Occam's Razor says you put at least one bad part on.

I don't know how much they'll charge you, but I know JMAC on State can pressure test the radiator. If it passes that would rule that out and let you buy a new water pump with a fair bit of confidence? I guess the other thing you could do is button it back up and use a UV dye test, but you'd wanna disconnect the fan so that you could be sure of knowing exactly where it's leaking from...

I don't like the idea of keeping Stop Leak in the cooling system permanently, I feel like it could eventually start plugging cooling passages, heater core, etc.

I've heard this too. Stop Leak is the kinda thing I'd use to get home, but I wouldn't wanna leave it in there either. I mean, I would, because I'm lazy like that, but I wouldn't want to.

 

[DaveB]

After seeing the leaks from both parts Occam would have to agree that both parts were bad or something is causing them to fail.

 

[DaveB]

I did a compression test yesterday afternoon and found that all of the plugs were burning very clean and the compression ranged from 120-130. There was no funny gunk on the oil fill cap or weird coolant colors. So it looks like the head/gasket is fine. Went ahead and ordered parts to fix all the issues I found on her Jeep.

 

[Brad J]

I don't know how much they'll charge you, but I know JMAC on State can pressure test the radiator.

I had an Excursion Radiator Cleaned and Flow Tested and JMAC for $42.98 in October.