I have a 64 Jetstar 1 and Friday, I tested the radiator cap and saw it was not holding pressure. The cap that was not holding pressure was rated for 15PSI. I went to the three auto part stores in town looking for a 15PSI, but all they had was a 16PSI or a 13PSI. The guy behind the counter said that I could use a 16PSI as that is what his computer was showing for my vehicle. I took his advice and put it on.

Last night, my wife and I went out for dinner in the Jetstar and this morning I saw that the coolant had drained onto my floor. I figured the cap was the problem.

I returned and picked up a 13PSI as the clerk said nothing could happen. Well I put it on, drove it about 15 miles and when I got home, it stared leaking again. It was leaking from the black box (pictured) which is located on the passenger side. I wish I was smarter about this car, but I was hoping one of you guys could help me.

1. Is the cause of the leak because I don't have the 15PSI cap on the radiator? Will it stop once I put the 15 rated cap on?
2. What is the name of this black box?
3. Is this normal to be leaking from the box?

Thanks for your help guys.

RadiatorFluidLeakingFromHere.jpg

 

The black box is the cover over your heater core.

Changing to a 15 psi cap will not change your problem.

The fact that you went from no pressure (cap not holding pressure) to 16psi (or 15psi - wouldn't have mattered) probably caused a weak spot in your heater core that was about to let go to finally let go.

Now that it's let go, it will continue to leak forever, regardless of what cap you use.

You need to replace your heater core.

Advance Auto Parts has it on sale for $40.00, and I'm sure all of the other places have it for a similar price.




- Eric

 

Eric,

Thank you for your help. I really appreciate it.
Mark

 

That's what we're here for .

 

Or, since you're in 'sunny California', take the two hoses and install a piece of pipe - by pass the core 'til you've the time and money.
You can even loop one hose to the other outlet!

 

Seeing as how it's winter here and about 15° outside right now, bypassing it didn't even occur to me, though it's an obvious solution. I have a hard time wrapping my brain around the idea of not needing a heater.

- Eric

 

California is a big state, looking to snow here tonight....Tedd

 

Well then, you shouldn't be driving anyway!! haha
Must be a small town- not in my atlas!

 

Thanks again guys. I think I will bypass it as I don't take her out when it's cold anyway.
When I do get around to changing it, is it difficult?

 

Since you don't have A.C. - not a big deal!
Good time to think about it though- lotsa aftermarket out there!!

 

When you bypass it, I would blow out the coolant in the heater core. Chances are it's from one of the 2 connectors, but to be on the safe side if you remove most of the coolant from the core it will also save you from the possibility of a leak inside. BTW, when you went for the drive did you notice the inside of the windshield was getting fogged up? If it was you probably have coolant leaking into the car already. check the passenger floor for wet or damp spots.

To replace the heater core, IIRC you have to do it from the inside the car.