Heat Problem On New B7500?

[DaRube]

My new B7500HSD was delivered Friday PM, and yesterday I went out to mow. After about 2 hours of vigorous mowing, the tractor overheated. This first one was my fault....there was lots of dust that had clogged the radiator screen. After letting it cool down, cleaning it off, and replenishing the water in the radiator (there was still lots of coolant in the overflow), with the dealers reassurance, I went back at it.

My problem was the temperature gage. I never paid it any attention prior to the first incident, but now it went to the high position, despite the engine definitely being cool. Again I called the dealer, who suggested perhaps the gage was stuck, and I should run it for a little while to see if it would go down (which it eventually did). But I did pay more attention to the temp as I continued my work. As I finished my lawn, the gage spent much time in the hot zone, only bouncing back down to the cooler regions when I was cruising the easier sections of the yard. I ended up shutting down just about every half hour to check the radiator screens, waiting five minutes, and resuming.

My configuration was: MMM only, set to 2wd, throttled to 2600RPM, high speed about 3/4 of the time. Mower raised through high grass, but I did return for a second cut with the mower lowered. Mostly flat property, but for one section where I did go straight up a 30 to 45 deg slope (20 feet long)....total mowed about 5 acres.

I would appreciate if anyone could help me understand what is going on with my temp control (I'm a newbie), and if I need to change the way I approached this task. Thanks!

 

[Wheeldog]

The B-series tractors are notorious for running cool. In my own experience, mowing in hot weather for several hours at a time and working the machine fairly hard, my temp. gauge barely gets above the 'C', if that. If the radiator is not completely covered, and if the machine has enough coolant, it seems like you must have some sort of restriction in the cooling system OR the pump is not pumping right. I think I'd get the dealer to have a look.

After thinking about this some more, I would say that the sending unit for the temperature gauge might also be the culprit. In either case, I definitely don't think you were 'over-working' the tractor.

<P ID="edit"><FONT SIZE=-1>Edited by Wheeldog on 09/16/01 08:48 AM (server time).</FONT></P>

 

[DaRube]

Thanks, Wheeldog!!

I'm going to give it another try today....carefully. And if it doesn't stay cool, I'll get ahold of the dealer tomorrow.

 

[ronjhall]

DaRube
I have a 2910. Whenever the temperature gage starts to rise. I raise the hood and remove the screen in front of radiator. While it is removed I wash all dust and grass clippings out of the radiator and grille. After things have dried out. I start tractor up. Gage will stay down low.
Make sure you check antifreeze before winter. Enough may have boiled out to not have the correct protection for both hot and cold.

 

[TWINKLE_TOES]

DaRube,

Welcome to TBN/w3tcompact/icons/smile.gif My wife's rig is the same as yours, B7500HST, 60" mid mount mower. She mows 3 acres, 2600RPM in Low speed (pedal to the metal) and the temperature gauge never comes up any higher than 1/4 to 1/3. Ambient temperature 60 to 70 deg's F. The HST reservoir temperature 160-170 deg F max.

About 1/2 way through her mowing job I change the deck height and clean the grill and radiator screen. It is always filled with grass. Even under these conditions the temperature is as stated above. The only difference I see is High Vs Low speed. I don't think I would hang my hat on a just a bad gauge from your description. If the gauge read hot when it was definitely cool it's bad, but initially it did read hot when it was hot. Is the brake stuck on? My guess, something is not right other than the gauge.

Al

 

[k8ny]

DaRube,
Ensure you do not have the brake in the locked position, this will cause higher than normal engine temp when running the machine.

Bob

 

[snowman]

Make sure that both screens are clear - both the fine mesh
screen that is on the exterior of the front and the pull-out
screen in front of the radiator (you need to open the hood
to pull it out).

I have a B7500HST and the normal temperature gauge is just
a little above "C".

I had mine actually overheat once when the interior mesh
got completely clogged. After that, it seemed to be running
hot even though the interior mesh was clean. It turned out
that the exterior screen was covered with fine dust.

Now, as standard practice, I always make sure both are
completely clear.

When the exterior mesh was clogged, the temperature gauge
would get very close to "H", but it never actually boiled over.

My guess is that is your only problem, nothing mechanical.

 

[DaRube]

Thanks, guys. After the initial overheat, I waited for it to cool down, refilled the radiator, cleaned all the grills, and gave it another try. The brakes were released. Although I didn't have it go over, the temperature gage spent most of its time in the medium to hot zone, sometimes going past the scale. It didn't take long for this to happen.

Anyway, I called the dealer this AM and he will come and take care of it.

Thanks for all your replies......this has given me a case of the jitters, but it sure makes me glad for the warranty.

 

[MarkV]

DaRube,

This may be late, given that the dealer will be checking things out, but there have been people who have found that the fluids on new machines were not topped off, as they should be. I would check my hydro fluid and oil to make sure someone didn't screw up during dealer set up.

MarkV

 

[theboman]

The airflow problem is a terrible on the B7500, it sucks air and the grill gets clogged and temps rise. It's not a problem bush hogging but when mowing I have to stop 2-3 times in the 2-3 hours I mow to wipe of the screen on the grill. I have complained to Kubota on the design flaw but no reply. I think Kubota should have a recall to fix this MAJOR design flaw.

Bluegrass, Pick It Up!