12.7 Detroit pushing coolant out of overflow

This started out with the fan not kicking on at 210*, coolant temp got up to 225 on me, and for the rest of the trip I drove it gently to keep ECT down. I figured if it ended up being an issue I could pull over and unplug the solenoid on the front cover and force the fan on all the time. There was only one more hill on my route, and I was careful to keep the temps down but they did get up to 220* on me. At the end of the day I find that coolant had been forced into the overflow and I was empty on the side you fill. I topped it off and headed home, now it is puking it out too fast to risk it so I'm finding a shop or having it towed. It got up to 230* on me so I let off and coasted into a truck stop and not risking doing anymore damage.

Anyone have any ideas? 98 Volvo just hit 1mil yesterday.

 

How old is the reservoir & cap? I have a 1998 D12 and replaced the reservoir + did coolant drain & fill.

I have not had a problem with rising coolant since.

All that done 35K miles ago, in March 2018.

 

Probably pretty old lol. Would that cause my overheating issues on hills too though?

 

Coolant temp goes up, as you go uphill. The fan clutch is supposed to trigger at 210* (or some number near that).

Is your fan clutch working?

 

That's the other issue I'm having. It kicks on and off at idle for the AC but not at 210 pulling a hill.

 

Test the fan.

While engine stopped. Try turning the fan with a stick, see if its grabbing

 

Yup it is stuck.

 

The test above, assumes motor was cold.

Anyways, check this video.

 

Yup mine works just like that. Key on, air pressure up it spins freely. Key off it doesn't move

 

go with a horton.