cherokee overflow tank leak

[irishsetter48]

My 1989 jeep laredo is leaking coolant at the overflow tank. I switched my overflow tank cap (working correctly) from my 1988 cherokee and the overflow tank still leaks. Can I assume the overflow tank is bad and needs to be replaced? The temperature gage is working and not showing overheating. No warning lights are on. Thanks for your help.

 

[XJNick]

Hi,

Are you saying it is leaking out of the hose connection(s) or from the cap?

-Nick :!:

 

[irishsetter48]

XJNick.
Thanks for your quick reply. It leaks from the cap, but the cap is new about 2 months ago and works fine on the 1988. Any ideas?

 

[90Xjay]

The cap is a pressure relief style on those systems. When it leaks, how much coolant is in the tank at the time, 1/4 full, 1/2 full? Either the cap is defective or too much pressure is building up. I had a cap go bad, and not keep enough pressure last month. My rig started running in the 210-215 range. I installed new cap, and found all of the hose clamps going to the tank a little loose and gave them a twist. Fixed the problem imediatley.

Good luck

 

[XJNick]

Hi,

It is possible that the coolant bottle's cap threads (which are plastic) have deformed just enough to not seal properly due to heat and old age. If a new cap won't solve it, you'll probably have to replace the bottle and cap as a set. :mrgreen:

-Nick :!:

 

[MudderChuck]

Had a hair line crack (in my 88 ) near the filler cap (hard to see), replaced the surge tank with my spare and a few weeks later had a crack in the same spot. Finally looked up and noticed the imprint of the tank lid in my hood liner. Looked in the 87 no problem, cleared fine?
Think I´m gonna figure out a way to lower the surge tank mount/bracket, before I install a new surge tank.