Hey Everyone,

I have an issue with my 99 cherokee 4.0 l v6. It's leaking antifreeze bad as soon as it warms up. I am unable to pinpoint the leak. It looks like it's coming from behind the water pump. Any suggestions? Thanks for your time.

 

Might need to pull both the water pump and t-stat cover for gasket replacement. Depending on whether the pump is leaking and where, it may need to be replaced. T-stat cover may need replacing as well.

 

With a beer in one hand you can replace both the thermostat and water pump in a couple hours even if you have never done it before. Probably needs it anyways. I just did mine today because neither were leaking yet, but they sure as heck will.
ETA:
Here

 

or you could have a cracked block like me doubtful tho. if you can find a way for a better look at it, it might help. pressure wash the front end clean and fire it up. without all the gunk on the pump and block, you'll probably be able to see where its coming from.

 

Replacing the water pump and tstat cover should be doable in a few hours if you are a bit knowledgeable already on flushing coolant and what not to do.

While you're draining the coolant you might aswell go ahead and flush it all out with a garden hose. The best way to do this is once drained, remove the lower radiatior hose from the water pump, and the upper radiator hose and heater hose from the tstat cover. This will help you avoid flushing gunk and build up from one area to the next and allow you to flush each individually. To flush, put the garden hose in through the top radiator hose and flush until clean water comes out, then put the garden hose on to the heater hose and flush until clean water comes out of the lower end of the water pump. Then, stick the hose onto the heater hose nipple on the Tstat cover, and flush again.

I'd also recommend loosening the bolts on the water pump pulley pretty good, BEFORE you untension the belt because its a real pain in the *** trying to loosen those once the pulley is free to rotate.



Just a few things I learned while doing the same thing just a few days ago.



also credit to djb383 for his flush method.

 

Thanks everyone for the fast responses. I am going to replace them later today. Ill keep you posted if i run into problems. Hopefully I don't run into a cracked block.

 

Again thanks everyone, it was my water pump and t stat. Jeeps running like a champ now. Have a great weekend.