750c heating problems

[Moffett cr.]

Has anyone had problems with their 750c heating ? Is their any thing i can do to cool it ? Has new water pump ,thermostat,pressure cap and is keep blown out.Just wondering if their might be an answer or maybe a different radiator?

 

[Mobiltech]

Is it pushing any coolant out the overflow hose?

 

[Moffett cr.]

What I meant is I keep it clean by blowing it out with air,sorry for not making that clear.Thanks

 

[Mobiltech]

When you say blown out make sure it is clean. I have been to many machines that are said to be blown out only to find that you can't see light through the core.
When its running hot and revved up the temp drop from the top to the bottom of the rad should be 12-15 degrees F. If its lower than that its plugged externally or has poor air flow. If its higher than that you have a coolant flow problem.

 

[Moffett cr.]

Thank you,if it were a coolant flow problem were would i go as i have changed water pump? I have back flushed radiator also? Maybe a bigger fan?

 

[Mobiltech]

If you have an internal rad flow problem you are better to send it to a rad shop and have them dunk tank or caustic clean it.

 

[d9gdon]

Have you checked the condition of your belts, pulleys, and belt tension? Make sure you don't have missing fan shrouds too.

I'm not too familiar with a 750C, but I'm betting there is a hydraulic cooler or AC condenser in front of your radiator that might be plugged or have trash between them? You may have to remove them to get them all clean.

 

[steve.k]

Those have serpentine belts and the pulleys wear flat and belt starts to slip. I just had this on a td25 that normally ran cool? We replaced all pulleys and can't get it hot now.

 

[Moffett cr.]

Thank you all, steve.k do you think the pulleys could wear out at 4200 hrs.? i have not change belts ,maybe start their?

 

[Delmer]

Get a non contact thermometer and tell us what the temps are for the coolant and air going into and out of the radiator. Or at least confirm that you can see through the radiator, I'm not the only one who is suspicious of "clean" radiators. Or throw some parts at it...

 

[steve.k]

Thank you all, steve.k do you think the pulleys could wear out at 4200 hrs.? i have not change belts ,maybe start their?

Our td25 had about 5800hrs so it is possible.The belt may have stretched far enough also that it slips a percentage.I thought it was the rad but we had it checked it was good.Then we were thinking it was a trans pump but it turned out good also?We were a bit stumped so the mechanic decided to check pulley's,they never looked that bad but we changed anyhow.It was amazing how much difference this made.

 

[Moffett cr.]

I can see through the radiator good and the fins look great.The oil cooler is to the side and it is clean. I will pick up a new thermometer and start their.

 

[Moffett cr.]

Steve did you have to change all pulleys? After I make sure it is not the radiator I will start on belts and pulleys. Thanks

 

[Delmer]

When its running hot and revved up the temp drop from the top to the bottom of the rad should be 12-15 degrees F. If its lower than that its plugged externally or has poor air flow. If its higher than that you have a coolant flow problem.

This is a simple way to narrow down your problem. Without this information you're jumping back and forth trying the next most likely cause.

How did the old coolant and drained flush water look when you flushed the radiator? The early serial numbers had two parallel thermostats in a rectangular housing going to the upper radiator hose, if you have that then it's not likely two thermostats both failed closed without something extreme having happened to cause it.

 

[steve.k]

Yes all pulley's however you can likely save ac pully and alternator on 750.I would also check the rad like previously stated with infrared heat gun to verify rad.

 

[Moffett cr.]

The old water and coolant was cruddy when back flused.