Temperature gauge pegs out

[ruffdog]

Did the engine seem real hot when the gauge showed it hot? I have had thermostats cause a cold/hot cycle and some t-stats have a small hole (.06") drilled in the flange to prevent that. If too much air is behind the t-stat, it may not feel the heat as if it was against fluid. The small hole lets the air past the t-stat so you don't have the cold/hot cycle.

 

[ruffdog]

Also, a t-stat that has been installed backwards will take too long to open the first time after starting:

https://everythingwhat.com/why-is-there-a-small-hole-in-some-thermostats

 

[stuckmotor]

An aftermarket temperature gauge might solve the problem or even if it didn't, help you eliminate some possibilities of what's wrong. They can be had for around twenty dollars.

 

[dambuster]

We have a Branson 2500. I was mowing the pasture, and the temp gauge was running in it's normal position. I glance down periodically while mowing, and I saw that it was pegged out in the red. I immediately shut everything down and moved to the shade. I checked for blockage/dust, and there was a little that I cleaned off. Went in and ate lunch to give it time to cool down. We checked the air filter, and coolant. We went ahead and replaced the air filter, because it was dirty, and it was time to replace it anyway. Started it up next day, and it stayed on cold. Started to mow and glanced down at the temp gauge, and it was pegged out on hot again. I hadn't even been mowing for 3 minutes.

Anyone else run into this?

Thanks for any help.

I had the same problem with a Finish mower on my Kubota L260. I checked all of the things that have been suggested in replies! No real change, things seemed "OK". SO, I checked the mower blades (for sharpness) then LEVELED the mower to cut flat parallel to the ground! It seems that a slight tilt of the deck forward caused enough drag/resistance...to cause tractor to do exactly what you described, until mower was lifted above the grass and shut down PTO to allow a few minutes of cooling! Then, I would do it again....until I tried to level mower cut and lift about one inch higher!

Just my experience...try it, it cost nothing.

 

[Cougsfan]

If it helps I will pass on more of my experiences:

If it is indeed overheated it will very quickly boil out the radiator fluid. If you shut the tractor down you can clearly hear it boiling without even opening the hood, and there will be a puddle of fluid on the ground. (I know this from multiple experiences). On mine the temp gauge has a very narrow range. The difference between OK and boiling over is extremely small. At around 40% of scale on gauge reading it is OK and seems to be normal, and at 45% she is starting to boil. If I keep running it, within about 30-60 seconds the gauge is maxed out after it started boiling and won't stop for 5 minutes no matter what you do other than hose down the radiator. As with most tractors I have seen, Branson doesn't seem to pay a lot of attention on the quality of their instrumentation.

And as with most vehicles I hate how they block the front of the radiator with other cooling devices. (in my case it is an oil cooler, an ac condenser, the engine air cleaner and the radiator overflow tank, plus the mounting structures for all that stuff. I understand why they do that, but what a PITA for cleaning. It has a screen but it doesn't catch the smallest chaff. Now I try to avoid mowing if the weeds have gone to seed. I should point out that these issues aren't confined to just Branson tractors. It is common tractor design.

 

[CMHigdon]

Thanks everyone for all your advice and suggestions. We finally got the water temp sensor, and that fixed the problem. I really appreciate all the help. You saved me from calling the local tractor repair guy, and spending a bunch of money to find out it was a $40 part that we could change out.

 

[TXCOMT]

If it helps I will pass on more of my experiences:

If it is indeed overheated it will very quickly boil out the radiator fluid. If you shut the tractor down you can clearly hear it boiling without even opening the hood, and there will be a puddle of fluid on the ground. (I know this from multiple experiences). On mine the temp gauge has a very narrow range. The difference between OK and boiling over is extremely small. At around 40% of scale on gauge reading it is OK and seems to be normal, and at 45% she is starting to boil. If I keep running it, within about 30-60 seconds the gauge is maxed out after it started boiling and won't stop for 5 minutes no matter what you do other than hose down the radiator. As with most tractors I have seen, Branson doesn't seem to pay a lot of attention on the quality of their instrumentation.

And as with most vehicles I hate how they block the front of the radiator with other cooling devices. (in my case it is an oil cooler, an ac condenser, the engine air cleaner and the radiator overflow tank, plus the mounting structures for all that stuff. I understand why they do that, but what a PITA for cleaning. It has a screen but it doesn't catch the smallest chaff. Now I try to avoid mowing if the weeds have gone to seed. I should point out that these issues aren't confined to just Branson tractors. It is common tractor design.

Man, I’m glad I’m not the only one this bothers…on my 2400H, the battery and the oil cooler sit in front of the screen and rad. Plus, the air intake tube is “smushed” at the top of the rad so it can fit between the latter and the hood. These design engineers must’ve gone to the same schools as their auto counterparts!

Anyway, congrats to the OP and all the great responses…this is an amazing forum!

T

 

[ericm979]

My 3725 has those same design features. The air tube maintains the same area through the flattened part- it's wider there. A change of shape with the same area has very little effect on air flow. as long as the change is gradual (as it is on mine).

The oil cooler has to go in front of the radiator as that's where the air flow is. Putting it elsewhere would require a separate duct and it'd need it's own fan. Putting it in front of the radiator means it's in the air stream generated by the fan. They just make the radiator a little larger to compensate for the warmer air it's seeing.

 

[TXCOMT]

Oh, I wouldn’t call them features! I understand the basic engineering rationale, but it’s still a pain to clean the screen and rad, period.

I especially applaud the thin metal tabs used to hold the overflow hose to the rad support…sheer genius.

TXCOMT