hydraulic fan speed

Topic: hydraulic fan speed (Read 1796 times) previous topic - next topic

hydraulic fan speed

May 14, 2016, 12:58:27 pm

I was reading through this topic Manual fan speed control for our 99 U270 looking for clues to why my fans went to high speed as I had placed engine into fast idle(1500 rpm). I did not check to see at what engine speed other than 1500rpm that fan speed went to high.
Is this an expected event or is this indicative of a problem?

Re: hydraulic fan speed

Reply #1 – May 14, 2016, 07:30:39 pm

@Bob,

All of the fan speed controls I have seen are thermostatic. So don't think going to high speed idle would cause the fans to go high speed. I would say unexpected. Can you reliably reproduce? If so I'd get on the phone to James at FOT and start asking questions. Unless someone on the forum has a better answer.

see ya
ken

Re: hydraulic fan speed

Reply #2 – May 14, 2016, 08:16:14 pm

I understand some may be low/high with an electrical switch. Long ago that was true on the ORED 300 cat if memory serves me.

No idea on a 99

Re: hydraulic fan speed

Reply #3 – May 14, 2016, 11:03:14 pm

Our coach has a thermostatic hydraulic valve that when closed puts the fans in high speed. Later coaches with computers, use a thermostatic electric control that, I think, when unplugged puts the fans in high speed.
I think ours kicks fans to high speed when coolant to radiator is over 185 degrees, (or is it 190 degrees?).

Re: hydraulic fan speed

Reply #4 – May 15, 2016, 12:13:03 am

My research has shown that the controller always runs at low then ramps up the fan speed starting at 175 and reaches full speed at the units rated 190 degrees. Variable.

Seemed to run too high of a fan speed costing hp IMO. Thermostat on my m11 does not open fully until 195 so I changed my controller to a full speed at 210 degree one instead.

Testing is ongoing so the long term correctness of the change is not available yet.

Hope is better mpg and power without a lot of additional heating.

Expensive controller that I found on a close out new cheap

Re: hydraulic fan speed

Reply #5 – May 15, 2016, 07:54:21 am

Bob,

Contact Source Engineering. The thermal valve they have is what you want. They are familiar with the Foretravel application. Comes in several temp settings.

Source Engineering
541-343-0293
90971 Roberts Rd, Eugene, OR 97408
sourcerv.com

Solved my fan running fast all the time several years ago.

Re: hydraulic fan speed

Reply #6 – May 15, 2016, 11:23:01 am

Quote from: Rudy – May 15, 2016, 07:54:21 am

Bob,

Contact Source Engineering. The thermal valve they have is what you want. They are familiar with the Foretravel application. Comes in several temp settings.

Source Engineering
541-343-0293
90971 Roberts Rd, Eugene, OR 97408
sourcerv

Solved my fan running fast all the time several years ago.

What caused you to think the fan was too fast?

What differences have you noted since the install?

I found the 210 unit for ten cents on the dollar new on eBay and had it changed out.

Barely driven it since.

Should have more power hopefully and better mpg.

Any noticeable temp increases?

Re: hydraulic fan speed

Reply #7 – May 15, 2016, 11:49:17 am

Bob,

With the engine cold, the fan was turning real fast blowing a lot of air. After the thermal valve replacement, it just turned slowly and I can hear it cycle when I stop at a rest stop.

I run at 179 to 185 on the VmsPC and about that on the dash gauge.

MPG stayed the same.

Re: hydraulic fan speed

Reply #8 – May 15, 2016, 02:03:08 pm

My 1993 U300 (DD) has two fans by the radiator. When I fire up Tuesday I'll have to check to see if either or both fans are running at startup. Then, when we land that afternoon, I'll have to see what they are doing. I have no idea whether they run together, or whether one runs and then the second one comes on as needed. Also don't know if they are two speed. How do I tell?

Re: hydraulic fan speed

Reply #9 – May 15, 2016, 03:55:06 pm

Quote from: Rudy – May 15, 2016, 11:49:17 am

Bob,

With the engine cold, the fan was turning real fast blowing a lot of air. After the thermal valve replacement, it just turned slowly and I can hear it cycle when I stop at a rest stop.

I run at 179 to 185 on the VmsPC and about that on the dash gauge.

MPG stayed the same.

The failure rate on the piloted wax capsule hydraulic fan control is extremely low.

Was your fan controller a Danfoss hydraulic non electrical controller?

"Hearing it cycle" seems to indicate a low/high electrical switch versus the variable non electric ones on the later units

Re: hydraulic fan speed

Reply #10 – May 15, 2016, 03:59:01 pm

Flash you need to go back and read Rudy's post, he said he replaced the thermal valve.

Re: hydraulic fan speed

Reply #11 – May 15, 2016, 04:21:00 pm

Quote from: Bill Willett – May 15, 2016, 03:59:01 pm

Flash you need to go back and read Rudy's post, he said he replaced the thermal valve.

Yes I understand that.

Lots of early and late cooling systems had an electrically operated low/high switch in the fan controller system.

My presentation of the hydraulic side drive ORED 300 cat grand villa included pointing to the wired valve and explaining to the customer that if the switch electrically failed the fan came on high.

Failed on. Not off. Same as the spring safety chamber rear brakes. Abscence of air applies the rear brakes. Fail on. Not off.

Rudys description of a rapid on/off low/high does not seem to match the ramping up in speed the Danfoss variable speed controller works.

My shop started to test my high low electrical fan switch until the foreman told me mine had a variable non electric controller

Re: hydraulic fan speed

Reply #12 – May 15, 2016, 05:15:33 pm

Not sure how my fans were interpreted to jump up in speed with the thermal valve operating properly.

With it failed, the fans were speeding up as the engine speeded up when the engine was cold.

New thermal valve and all is well. They are at a lazy idling speed till the engine needs cooling.

Re: hydraulic fan speed

Reply #13 – May 15, 2016, 05:32:18 pm

Bob,

I have the Hi/Low fan speed switch that will default to Hi-speed if it is disconnected or you pull the fuse under the dash even at idle. Both fans run simultaneously and the fan speed increases with rpms (my fast idle is 1000 rpms) under normal temps. I believe the thermostatic hydraulic valve will take over above 190 degrees and run the fans at the maximum till it cools down to normal operating temps. I'll have to check it with the Pro-Link to get the exact temperatures.

Jerry

Re: hydraulic fan speed

Reply #14 – May 15, 2016, 07:50:41 pm

Quote from: coastprt – May 15, 2016, 05:32:18 pm

Bob,

I have the Hi/Low fan speed switch that will default to Hi-speed if it is disconnected or you pull the fuse under the dash even at idle. Both fans run simultaneously and the fan speed increases with rpms (my fast idle is 1000 rpms) under normal temps. I believe the thermostatic hydraulic valve will take over above 190 degrees and run the fans at the maximum till it cools down to normal operating temps. I'll have to check it with the Pro-Link to get the exact temperatures.

Jerry

Kool. I do not think my u320 has the electrical switch in the system. Mechanical variable only as far as I know. I think Rudys 95 has a similar system to your 93.

We are learning things. Which is good

Re: hydraulic fan speed

Reply #15 – May 15, 2016, 08:01:44 pm

Whitehouse products in England, has wax valves with lower temps.

Re: hydraulic fan speed

Reply #16 – May 15, 2016, 08:25:01 pm

Quote from: Bill Willett – May 15, 2016, 08:01:44 pm

Whitehouse products in England, has wax valves with lower temps.

Needed higher. On too much IMO

Re: hydraulic fan speed

Reply #17 – May 15, 2016, 08:29:01 pm

Thanks, Jerry. I'll look at the engine when we get back to the coach next week. I see yours is 100 units older than ours.

Re: hydraulic fan speed

Reply #18 – May 16, 2016, 07:29:54 am

Good discussion gents. I had added a bottle of HD Barsleak and wanted to circulate it. Isolated water filter then started engine.After idling about 5 min engaged fast idle at 1500rpm. Engine was not warmed up but fans were definitely on high. Later after feeling hot coolant circulating to radiator went to idle and fan speed went to slow. Time permitting I may slowly increase rpm and with helper find out what rpm the fans go to high.

Re: hydraulic fan speed

Reply #19 – August 31, 2017, 03:23:15 am

After digesting the changes that Caflashbob made I decide to pull the trigger and replace the hydraulic fan control valve. This new valve is fully open at 199ºF and starts opening about 187ºF. This spring we traveled from California to New Hampshire with a total of 4560 miles. I am happy to report a significant mileage increase to 9.6 mpg, which should recover the cost of the valve in approximately two years. Prior to the change the best mileage recorded with VMSPC was 8.4 MPG. The mileage was calculated using real world conditions such as mountains, traffic, wind, road conditions, etc.

Bob

Re: hydraulic fan speed

Reply #20 – August 31, 2017, 12:41:23 pm

My coaches engine memory showed a 100k mile 7.7 mpg.

Last 11k miles is 8.2.

I tow at 70-75 mph a 3,600 pound solara convertible and use the engine hard up grades.

I assume the prior owners towed at much lower speeds than I do.

Short runs at slower speeds have shown similar mpg results to Bob's

Got 11+ across Nebraska at 60 until I could not stand it anymore and raised the speed back up.

Stock Danfoss controller started ramping up at 165 degrees and was fully open at 180.

No difference in engine temps noticed after 11k miles including a recent Las Vegas desert hard run

Coach pulls better at low rpms with the mode on.

But a changed to a resonator also.

Re: hydraulic fan speed

Reply #21 – August 31, 2017, 12:47:27 pm

Quote from: flite2010 – August 31, 2017, 03:23:15 am

After digesting the changes that Caflashbob made I decide to pull the trigger and replace the hydraulic fan control valve. This new valve is fully open at 199ºF and starts opening about 187ºF. This spring we traveled from California to New Hampshire with a total of 4560 miles. I am happy to report a significant mileage increase to 9.6 mpg, which should recover the cost of the valve in approximately two years. Prior to the change the best mileage recorded with VMSPC was 8.4 MPG. The mileage was calculated using real world conditions such as mountains, traffic, wind, road conditions, etc.

Bob

What source and price? Where is this mounted?

Re: hydraulic fan speed

Reply #22 – August 31, 2017, 01:44:37 pm

Be sure that the controller is LOW to HIGH, and not OFF to HIGH. And, I agree, High should not come on until 5-8 degrees F above thermostat full open temperature.

Even with low coolant temperature you need air flow through the CAC.

Re: hydraulic fan speed

Reply #23 – August 31, 2017, 02:51:22 pm

The fans are running at 270 RPM at engine idle cold.
Mine is located on the return from the engine thermostat to radiator. Thermo valve kit Monaco/CC is available at Source Engineering Inc. 541-343-0293
I paid $550 in September, 2016

Re: hydraulic fan speed

Reply #24 – August 31, 2017, 03:00:56 pm

Bob,

Of interest would be intake manifold temperature. As long as it is not significantly higher, sounds like a great upgrade.

Affiliate Notice