Radiator Cap Leak, or overflow hose?

[Ryan Thomas]

I think I already know the answer to this one (I have a new cap on the way) - but does this look like it's leaking from the radiator cap just above the overflow hose? Or, does it look like it was coming out of the hose?
Also, there is not usually a hose clamp on the hose right there, is there? I don't remember there being one, at least...

Happy Thursday!

 

[Chris]

Looks like the cap to me! Thought maybe it's not leaking at all. Any chance it's just spilled coolant from when it was filled last?

 

[Ryan Thomas]

Looks like the cap to me! Thought maybe it's not leaking at all. Any chance it's just spilled coolant from when it was filled last?

Unfortunately, no - it's definitely a leak. Driving normally on the roads it is fine - but try wheeling up a steep incline, and all of the sudden the temp goes up, and I smell a bit of coolant burning off of the radiator (Tried going up Nate Harrison Grade Road as a first wheeling test after the rebuild, and had to turn back!). Otherwise, It runs just under the 210 mark, as it should.

Luckily, I ordered a new cap that will be here tomorrow or Saturday! I need to get this heat issue resolved so I can feel more comfortable with taking it out for "proper" wheeling...

 

[Chris]

Rebuilt the entire engine but forgot the radiator cap?

Kidding!

 

[Ryan Thomas]

Rebuilt the entire engine but forgot the radiator cap?

Kidding!

I wish it were my fault! The radiator was done by the shop I was going to before I found the Jeep guys who I let do my engine. The engine guys were good - the people before them, not so much

 

[Chris]

Ahhh! Well, fortunately it's just a measly radiator cap!

 

[Jerry Bransford]

Make sure the new cap has the proper 18 lb. pressure rating.

 

[Ryan Thomas]

Make sure the new cap has the proper 18 lb. pressure rating.

Yep! I made sure when ordering it, and will definitely double check it when it gets here.

 

[Ryan Thomas]

Hmmm... two new caps (one from Mopar, and one from Stant) and both leaked. The Mopar cap leaked pretty badly, and the Stant one was about 1/4 as bad - but still leaked.
Going to try it again in the morning and see if it still leaks, but I'm not holding my breath!

 

[UPJOHN]

That radiator in your picture looks different than the one in my Jeep. Could it be that the stock Jeep cap doesn't fit properly?

 

[Ryan Thomas]

That radiator in your picture looks different than the one in my Jeep. Could it be that the stock Jeep cap doesn't fit properly?

It is, unfortunately, an aftermarket radiator (that I am still contemplating switching out). It is new, and should work with a stock cap - but something is definitely up. The caps are pretty much exactly the same as far as measurements go, and pressure ratings, but who knows!
The next thing I'll do is see who made the radiator and get one from them.

 

[Ryan Thomas]

Ok, so it looks like it's the CSF 2576 radiator, so I'm keeping it in the Jeep - but I'll be damned if I can't get a cap to not leak!
The original cap stays sealed unless I have to climb something really steep (like sections of the backside of Palomar Mountain), but driving it on the highway etc. it's fine.

It is definitely coming from the cap too.

Water pump, Thermostat, Radiator, overflow tank are all new and on a freshly rebuilt engine -

So far I've tried a cap from the Jeep dealer, and Stant. Can't get an actual CSF cap anywhere today, but I'm going to have to try that next maybe...

 

[Chris]

Ahhh, yeah, if you ever have to replace that radiator make sure to just put an OE Mopar radiator in there. They're the best!

 

[Ryan Thomas]

Ahhh, yeah, if you ever have to replace that radiator make sure to just put an OE Mopar radiator in there. They're the best!

Yeah, the guys I took it to (before the place that I let do my engine) were, let's just say, not detail oriented...
While I do think the CSF radiator is a good substitute, I still think I might just bite the bullet and pull some money out for a new Mopar replacement.

Plus, I really want to have the transmission lines and power steering lines replaced (along with the tensioner pulley and the one other block-mounted pulley) - so might as well have it all done at the same time.

Going to have to find a new shop, though, as the one I've been using is too far away and will also be moving even further away soon :/
The future needs to get here so I can get arm transplants and be able to do this crap myself again!

 

[Ryan Thomas]

Well, on fear of jinxing myself, it looks as if maybe the third time's a charm!
I decided to try a cap from Napa (I mean, for 5 bucks, why not) - it turns out to be a Motorad cap, which I had seen various reviews of - and it seems to have worked!

I did also make sure all the mating surfaces were free of filth etc. by using my fingernail and a paper towel - there really wasn't anything to speak of, but maybe it helped...

Going to give it a real drive later and see!

 

[Chris]

Awesome news! Hopefully this one works out okay!

 

[Jerry Bransford]

Try the first two new radiator caps again now.

 

[Ryan Thomas]

Try the first two new radiator caps again now.

Hah! You know, Jerry, I thought about it - but I'm too afraid to re-leakify my Jeep!
I'll keep them in the console just in case...