Hello all- My 773G is overheating slightly ( creeping into the yellow band ) only when I work it the hardest with a heavy duty brush hog. Coolant level is OK so I thought I'd replace the thermostat. Do I need sealant and a gasket for the housing or just a gasket? Thanks!
I usually put a little sealant on both sides of the gasket..... Ed
Is your radiator and hydraulic cooler clean?
THat's the first thing, I would check, too
Thanks folks. Yes the radiator is clean. I'm a little worried that it may be a bigger problem but I'm going to try the thermostat first. Is it possible to have a head problem if no coolant is getting into the oil ? Sometimes I do see what looks like steam on coming from the back and bottom of the engine but I can't find a leak anywhere. Any help greatly appreciated.
Pressure test the system to see if it holds
If it has a block heater in the head check that it isn't corroded and leaking at the pins for the cord.
Thanks. What's the best/easiest way to check pressure?
You can buy a kit to pressure test the cooling system or a repair shop should have one. There should be signs of leaking though. http://www.stant.com/files/3514/0979/5293/Pressure_Tester_Adapters.pdf
Thanks Dave. Hope that's not it. Where do you think the steam under the bottom of the engine is coming from? Only happens after the temp creeps to the yellow mark. There's a small coolant line running under the engine to somewhere but I can't see the front side of the engine ( closest to the cab ) even when raising the cab and the engine running.
Can you take a belly pan off and look up from underneath? It could be something as simple as a loose clamp or a pin hole in a hose. Drive it up on some planks or block it up to get more ground clearance. You have to find a way to look to see where the leak is coming from. A constant running brush hog would add a lot of heat especially without an aux. hyd. cooler. All the hyd. heat and constant load would certainly contribute to the engine getting hotter.
Sometimes you can use a selfie stick, or strap a phone, to something, and maneuver it to take a picture or video, of the leak...
I'll give the belly pan idea a try. Didn't know I could take it off. I'll have to check and see if I have a hydraulic cooler stacked with the radiator but pretty sure I do. Where would an aux cooler be? I have a high flow option but don't know if it works. Think I should be using it with that bush hog? The bush hog is a lower flow model - says not to exceed 20 GPM. What does the high flow do? Never used it but the button lights up when I press it. I've always used the machine in the regular mode. Maybe that's the problem? Thanks again.