Community Forums

RVBob7 · 08-30-2017, 06:16 PM

My Beaver 2005 CAT C9 400 HP engine over heats when climbing a hill. The Transmission Temp gauge gets up to 230 and the Water Temp gauge reaches 240. Once I start back down the hill both of the temperatures gradually return to normal. If the hill is long enough the Check Engine light and the Engine Warning light comes on. I have driven trucks for years and I have never heard of this. I have spent $1500 on expert mechanics and the problem has not been solved. Any ideas you can give me would be greatly appreciated.

pplwizard · 08-30-2017, 06:20 PM

Drop to lower gear... Increase RPMs. I've done the Eisenhower tunnel 4 times in the last 3 months (11,000 feet) no problems.

1bomoe1 · 08-30-2017, 06:26 PM

Does it use a Horton fan clutch ?

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pplwizard · 08-30-2017, 06:27 PM

P.S. I have a Cat 350 TD

beaverfever · 08-30-2017, 07:00 PM

have you cleaned the radiators?
i started using foaming coil cleaner and was amazed the crud in mine even when they were cleaned a month previously.

Rocky68D · 08-30-2017, 08:34 PM

The Allison usually does a good job finding the right gear but on occasion I've had to manually downshift. The main thing is to keep the RPMs above 2000.

If you already knew that from your experience and I'm insulting your intelligence, my apologies.

Keith

rver98 · 08-30-2017, 08:51 PM

I'm not sure if your C9 has a side radiator or rear. Side radiator issues are usually due to the hydraulic fan not coming on and cooling the radiator or a sensor issue.

Rear radiators usually need their "subber tube" extended to the rear of the MH. Radiator and CAC need to be cleaned at least once a year with Dawn dish washing soap (my preference).

JFXG · 08-30-2017, 10:09 PM

X2 on beaver fever' remark. Particularly with the side mount, a clogged radiator will play havoc with you. I had exactly the same symptoms as you a couple of years ago. There're about three units mounted in that assembly, and they get really gummed up.

2 Stroker · 08-30-2017, 11:48 PM

Well I'm going to say it has a side radiator. If you do can you hear it when it ramps up.
Mine was getting to the point where I could hardly hear it plus I could see the temps come up on my Silverleaf. When mine got to 210deg on a 6% grade in the past it was 204deg it was time to get the wax valve installed. Now my coolant temp runs 194 down to 170deg and the trans runs about 170deg all day long.
Do you know if the t/stats have been changed, there are 2 one may be bad, is it low on coolant.
2 stroker

dskimball1 · 08-31-2017, 03:42 AM

I had the exact same issue as described. I have a 350 hp cat c/7.
Several people on this forum recommended what finally proved to be the solution;
Radiator and trans cooler needed complete cleaning. I had them removed and pressure washed with water and concentrated cleaner. Removal is necessary to ensure all sides are cleaned. There is a problem with C7 where the 21 quarts of oil (being too much) results in significant oil spraying out as you drive. That oil coated the rad and of course dust and dirt stuck to rad causing blockage.
Per Caterpillar reduced oil to 19 quarts, and extended hose so excess blow by oil is drained below the rad. Repair worked like a charm! Now running at 180 degrees max. Trans temp is really low. Problem solved!!!

Ludmilla · 08-31-2017, 02:56 PM

As already stated, if you have a rear radiator, you need to extend your slobber tube and clean the CAC and the radiator. Use Extreme Simple Green. Find out how you can access the front of the CAC and blow the Simple Green solution through while running the engine. Also have the radiator steam cleaned from the back. It make take multiple tries to get it clean.

Also run 2300 - 2500 rpm by manually downshifting. Slow down so you are not flooring the accelerator.

mtofell · 08-31-2017, 06:16 PM

My first thought from the symptoms is something cooling related. Restricted flow of fluid due to corrosion is probably the first thing to rule out. I had an incident in a truck one time and the roadside mechanic felt around the radiator with his hands and could tell it wasn't flowing properly due to how hot/cold it was in various places. I'm not even sure if that's even a way to diagnose but he was right. I had the radiator cleaned out and all was well from then on.