Motor Home Overheating - Beaver 2000 Patriot

[jauguston]

Ray.IN,

Actually engine speed does vary fan speed in the most common hydraulic driven fans. The pump out put varies with its speed and that relates to varying fan speed.

Jim

[GA Navigator]

Originally Posted by jauguston

Ray.IN,

Actually engine speed does vary fan speed in the most common hydraulic driven fans. The pump out put varies with its speed and that relates to varying fan speed.

Jim

I don't know if they're all the same, but my old side radiator fan does vary speed up to a point. I guess as the fluid flow increases, so does the fan speed but it seems to hit a max at a certain engine RPM which probably is related to some maximum fluid flow rate or pressure relief valve, etc.
FWIW my coolant temp stays at 180 degrees regardless of conditions. The transmission temp stays at 180 also unless I sit at a red light for a long time then it will increase to about 200. I've also seen the transmission temp rise a little bit when climbing steep hills at slow speed within a state park, etc. I try to speed up enough to get torque converter lock-up in 2nd gear to prevent the temp rise but it's not always possible.
Apparently, the torque converter makes a lot of heat until lock-up.
Sorry if my post rambled on.


1994 Holiday Rambler Navigator
Cummins 8.3
Allison MD3060

[deandec]

Originally Posted by Ray,IN

I thought all side-radiator chassis have a hydraulic driven(may be a electric too) cooling fan. If that is correct, RPM is immaterial to cooling fan speed. RPM does control water pump speed, which is more important.

You may be absolutely correct, but that does not help the OP.

All I know in our frequent uphill travels in the West Coast mountains these past 13 years from sea level to 7,000 feet in 70 miles, is that with the RPM's below 2000 rpm the water temp rises rapidly and can be reduced by keeping the rpm's above 2000 on my side radiator, Cummins equipped rig similar the OP's.

That was the message I was trying to convey to the OP.