tds

My 1967 Toro is overheating. Granted, it has been hot in Texas lately, but even driving on the highway (when it is moving at 65) it is overheating. I have no leaks, and no funny noises. Is it possible that the water pump has stopped working? How could I try to check it without removing it?

Thanks,

Tom

droldsmorland

It overheats at low and hi speeds? What device are you using to determine temp? Use another known method to compare just to make sure its not a bad gauge. Next I would look at the T_Stat and the radiator. It sounds like a bad stat or a restriction in the rad. Whens the last time it was flushed? A freewheeling impeller is rare on a water pump. Though it is possible but unlikely. Hows everything else. Coolant condition and level, belts hoses etc...The T-Stat is a quick simple swap. Just spend the money on a good Heavy Duty Stant. 180 or 190*

Octania

what has been replaced lately?

Lower radiator hose?

If not fitted with a spring inside they can suck shut and impede coolant flow

tds

Thanks for the suggestions. I'm using the stock guage to read the temp. The sensor and both hoses were replaced about two years ago. I put in a Fail Safe thermostat about a year ago. It ran fine on Saturday night, and I noticed a weak spot on the top hose at the show. Got a new top hose and installed in on Sunday. Took it out on Sunday afternoon and it started to run hot - all the way up to the top of the guage. Coolant levels were fine.

I'm gong to try replacing the thermostat first and go from there.

Appreciate your help!

Tom

joe_padavano

The water pump is almost never the cause of an overheating problem. The usual water pump failure mode is that the front bearing goes bad, followed immediately by the front seal. The large puddle under the car gives this away. Look elsewhere, mainly t-stat or plugged radiator.

Fun71

Yes, it is possible but very, very unlikely. I was unfortunate enough to have a stamped steel impeller separate from the water pump back in the 80s and there was no mistake about it running hot. As soon as I started the engine the temperature started climbing and it didn't stop - it would boil over in 5 minutes.
So if it isn't boiling over within minutes of starting the engine, it's likely not the water pump.

droldsmorland

And just because the T-Stats new doesn't mean it aint broke. Simplest, cheapest fix to try is a new high quality HD Stant T-Stat. Ask for the HD equivalent part. Its on line too. Dont buy a big box POS china junk. Thats probably what you have in there now? Pull the cap and warm the engine until the stat opens, look in the rad and rev it up looking for movement in the coolant. That will tell you at least the top of the rad is flowing. Shut it off and let it come back down to ambient. Put the cap back on then fire her up again and bring up to op temp. Monitor the rad temp as its warming up to op temp and the stat fully opens. Feel the rad tanks throughout the warm up. They should get warm all the way to the bottom. If not chances are good you need a re-core or at min rodded out. I prefer a re-core to rodding. Is the rad original? Has it ever been thoroughly flushed? To flush the heater core you need to remove both lines off the engine and flush it separately with low pressure from a garden hose. Make sure you remove all tap water before refilling it with the premixed 50/50. Or make your own mix using distilled water not tap water.
Other things to check...do you have the factory fan shroud in place in good shape? Is the trans slipping throwing more heat than normal at the rad. Have you verified the clutch fan is in good serviceable condition? Have you verified the rad cap is holding pressure on the system?
My gut says if the new t-stat or rad cap doesnt do it you need a recore.

oldcutlass

I think you should put in a temp mechanical gauge which can be had at your local auto parts store so we can see exactly what its running.

Octania

I heard "the gage said it was hot"

Not "I know it is hot"
Did it smell funny, run low on power, feel hotter than normal?
Super cheap IR thermal instrument can prove or disprove temp readings from other sources. Can you try a different temp gage sender?