coolant overflow

[Tony G]

The cooling system parts on my 89 xj are new (rad,water pump ,thermo sta,overflow bottel and cap) and I still get overflow when I turn off the enging. The coolant goes to the top and after 20 to 30 min it goes down about an inch from the bottem. If I fill it up it just overflow. Help me, Thxs....

[Eagle]

Do you have a 4-cyl or a 6-cyl?

The 4-cyl has an overflow/recovery bottle. The 6-cylinder does not. On the 6-cylinder, the plastic bottle on the firewall is NOT an overflow/recovery bottle. It is part of the pressurized cooling system. It should be filled only halfway. When cold, remove the cap -- there's a post inside directly under the opening. Fill to the top of the post.\\Caution -- that bottle is under pressure. DO NOT open it when the system is hot.

[rixXJphx]

If 6-cylinder, that bottle cap is a pressurized cap. It's designed to hold about 15psi.
It goes bad occasionally, and can be damaged by overtightening.

Don't forget to check it, and replace as required to maintain optimum cooling system performance.

[Tony G]

Thanks, I'll try a new cap it has striped before.