960 overheating

[Phil960]

Decided to clean the shop out yesterday so I pulled the 960 out onto the drive and left her idle for about a 1/2 an hour. When I got on it the temp guage was just in the red and antifreeze coming out of the overflow. Put it back inside and shut it down. Picked up a thermostat today and promptly broke the cast thermostat housing. I'll get one ordered tomorrow. Anyway, the old thermostat appears ok, not hung up, not sticking. I'm going to put a new one in anyway but, if that does not fix the problem am I looking at a new water pump? If so, How much disassembly is required? Looks like I can get at it without removing the radiator, but can I? Or is there something else I need to look at before swapping out the water pump?

Thanks in advance for any help.
p.s. anybody know the torque recommendation for those stat housing bolts. I'm guessing a bit less than what I tightened them this time.
 

[showcrop]

You didn't over tighten. you just didn't have the lip of the T-stat in the groove. Don't ask how I know.
 

[old]

It is simple to test a thermostat if your wife will let you that is. Simply take a pan of cold water and drop the thermostat in it set it on the store and heat the water. Have a thermometer in the water and watch for when the thermostat starts to open. Note the temp. If correct not likely to be your problem if not correct well you should know that answer
 

[FarmerZeb]

i second what showcrop said about the t-stat being
in the correct position before tightening - btdt

on the overheating if the thermostat is good i
would check the following

radiator cap
water pump check belt for tight then look at the
pump
flush the block using old's vinegar technique
fan shroud (as in do you have one)
ignition timing

most of this i learned from the guys on here about
six months ago on my 960

-paul
 

[Phil960]

Thanks Guys, I appreciate your help. I guess I just don't understand what happened. It had been running fine and all of a sudden it's not. It seems that the common sense approach would be the stat since they are either open or closed. The water pump/ fan belt is adjusted to about a 1/2 inch deflection and in decent shape. The fan shroud is in place. I'll keep investigating. For me this is the fun part, working on the old girl.
 

[Dean]

Did you change ANYTHING prior to the new over hearing problem?

Do you live in a cold climate? If so, might the coolant have slushed?

Is the bottom radiator hose old and soft? If so, it might be collapsing.

All indications point to coolant circulation issues.

Dean
 

[john in la]

It sounds like you have a coolant circulation issue like Dean said but I would not be willing to point a finger at the water pump just yet.
Fact is I can not ever remember finding a pump that did not pump water. The bearing may go out and you can shake the fan around; the seal may go out and it leaks; or pieces may berak off causing the pump to explode; but never one that ran good with no squeaking stop pumping water.

Even without a fan and or shroud and or engine timing way off the system should keep up with a idleing engine especially this time of year.

If you check your old thermostate in a pot of hot water and it opens you will have to look elsewhere for the problem.

I am betting on either (in this order)
Slushed up because of cold weather
Hoses going bad
or a piece of junk has broken off and blocking your engine water ports.
 

[mgriff543]

John is right about the water pump, about the only way it's the problem is if the impeller suddenly just fell off the shaft, and that's really unlikely. Good luck, Mike
 

[old]

A thermostat can be just fine today and tomorrow just plain and simple not open due to being stuck. I would do the water pan test to start with then go from there. Never good to throw parts at a problem till you know what the problems is. Your system may just need a good old vinegar flush for that matter but that is a bit harder to do this time of year due to vinegar will freeze
 

[Phil960]

Dean, I did just change the manifold and muffler prior to the overheating problem.
I do live in northern Indiana but had used the tractor to plow snow with earlier in the week and it was fine.
Second time it overheated, it was sitting in the shop which is heated.
The radiator hoses appear fine but I do have new ones if needed.

I'm going to flush the system as suggested and wait for the new stat housing to come in.

Thanks for your help.
 

[souNdguy]

flow test the rad and make sure the core is clean and open