Good Morning All,
I have been working on making my 2 hydraulic radiator fans run at top speed. Foretravel Specs:
Pump Output 1600PSI @ 2750RPM
Fan Speed High 2930RPM @ 2750RPM 2250RPM
Fan Speed Low 1900RPM @ 2750RPM 1600RPM
For several years I have know that the fans and the power steering were tied together some way. I have two(2) fluid tanks, up until a few days ago I thought I had only one hydraulic pump(pump w/belt). I now know that there is a pump driven by the CAT 3116 Air Compressor on the back side of the compressor. I have been told lately that the systems are tied together as a backup. If the power steering pump goes out the system will still/rob from the fan system to maintain steering. I was told that the "star value"/priority value does this by giving that power steering system over the fans.
Now that I have found the second pump, can a bad/week/something wrong pump make may fans run slow?? The "star value"/priority value when closed(low PS priority setting) does not effect PS. At idle I have good PS.
Pat,
News to me! Never heard anything about this from reading on the Forum.
Our coach has the two separate hydraulic reservoirs, and two separate hydraulic pumps. The cooling fan pump is belt driven - the power steering pump is driven off the rear end of the engine air compressor. I have always "assumed" that the two systems are completely isolated from each other. I have never found any hydraulic line connecting the two systems.
Best I have been able to determine, my cooling fans do
not have a "2 speed" control valve. If it exists, I have not been able to find it. My cooling fan speed seems to be totally engine RPM (pump RPM) dependent - IE as the engine RPM goes up the fan speed goes up.
I rebuilt our cooling fan pump 5 years ago. I bought a cheap non-contact tachometer at Harbor Freight to check the fan speed before and after the rebuild. I only checked the speed at idle - don't remember what the RPM was.
https://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html
Vickers V10 Hydraulic Pump Rebuild (https://www.foreforums.com/index.php?topic=23846)
Yours may be different but my hydraulic fans run on high speed by way of a solenoid bolted to the chassis, drivers side basically across from the coolant filter (Cummins). If I remove the top nut and take the solenoid off it defaults the fans to high. I have 2 pumps and nothing is back up of another. In addition, my fans don't kick to high until 203'ish degrees.
My system is the same. My system has a small aluminum block on the opposite side(passenger side) that has a nut and allen head wrench nut. I was told by FT that this "star valve" controlled the amount of fluid that went to the power steering. They told me to adjust it so that at idle I had a little power steering help. They also said that it controlled the max speed of the cooling fans. I saw them turn it and say that "we should be able to to make them sing". This happened when I had them work on the slow speed of the fans. They replaced the hydraulic pump and the star valve(4 yrs ago) and then told me after $2500 that the 2 fan motors were at fault and I should replace them. I bought them from FT for $2400 and put them on myself. I still have the old fan motors. I also still have 2 fans that are still running slow by about 6-7 hundred RPM. That makes my little kitty CAT run hot real easy.
I got on this problem again due to the fact that my CAT 3116 Air Compressor has gotten week. I am replacing it and I noticed a pump bolted onto the rear of the air compressor. I did not know that I had 2 hydraulic pumps on my MH. I thought I had only the belt driven pump and it did both PS and cooling fans. I just want my fans to run Fan Speed High 2930RPM @ 2750RPM and mine is still at 2250RPM.
I don't suppose you have a photo of that solenoid? I don't think there is anything like that on my coach.
Some have it, some don't. Foretravel. Go figger, eh?
I have the same solenoid, the ground connection from the coil goes to a temperature switch mounted on the side of the block below the turbo. Contacts are N.C. until temp reaches 190* then it opens and drops out the coil to the solenoid and with the coil de-energized high flow is directed to the fan motors.
Twig,
Thanx for the photo confirmation. Nope, I don't have one of those solenoids anywhere in the engine compartment. I woulda seen it.
We have never had a overheating problem, so whatever controls the speed of my fans seems to do the job.
Perhaps, because the '94 and '95 GVs are closer (mechanically) to the Unicoach, they got a upgrade to the cooling fan system.
Mine had the same solenoid controlled by temp sensor in water jacket near thermostat. The thought was to increase diesel mileage. When my temp sensor failed and I overheated my engine, I removed the ground at the solenoid and ran it to the dash on a spare wire, where I installed a rocker switch to control the speed of the fans. At 1500 rpm I can switch the fans from low to high speed and see the decrease in rpm by 30-50 rpm. That shows that the high speed fans do take some power to run and would decrease diesel mileage. In cool weather or early morning I can run on low speed fans. My problem is that my fan speed is about 600-700 rpm slow on both low and high speed.
Just FYI
I found my OEM PS pump(new) for $389 on internet, FT wanted $692, found a rebuild shop for $325
Vickers Pump V10F1S5T38C4H20
be here in 3 days UPS.
Pat,
Good find!
For other members who might have this same V10 pump, if you have pump problems and are not lucky enough to find a new one, there is hope! It is possible to rebuild the pump, and the process is fairly simple. The trick is finding the parts. Details linked below:
Vickers V10 Hydraulic Pump Rebuild (https://www.foreforums.com/index.php?topic=23846)
Update:
I have a Marine Corp.Trained Grand Son that works for John Deere in Beaumont, TX. He is a job site diesel/hydraulic/what ever it takes mechanic. I asked him
I really don't under stand the two systems. Is it common to have two pumps with 2 tanks? how to they keep the right amount of fluid in the tanks? Is that star-valve where the two systems are tied together?
He responded
On our equipment there is a hydraulic pump and a fan pump. The fan pump runs the fan under all conditions unless the hydraulic pump fails then the priority valve shifts over and the fan pump will run steering and/or brakes. It is strictly a safety thing. They would rather you were able to steer and stop in a failure situation. On deere they use the same tank but the priority valve is supposed to shift and separate the systems
I still need more help to understand, 2 pumps, 2 tanks and how they keep the fluid level in each system correct.
Pat,
Update for this old problem,
I have now after 4 days made a drawing of the hose nightmare that FT created. I now know more about the system also.
1. Star Controller is nothing more that a safety valve for over pressure.
2. The Hi/Low solenoid valve is a on/off valve nothing more.
3. The fans run as fast as the pump sends fluid.
4. My original pump was a John S. Barns(w29a-18000118) not available anywhere.
5. My replacement pump is a Sauer/Danfoss(80002642).
FT replaced the pump and Star Controller, I replaced both fan motors with new ones and the Hi/Low Solenoid Valve. With all new components my fans still run about 700rpm slow on both hi and low speeds. Otherwise the system works fine. I added a switch on the dash to control the Hi/Low Solenoid Valve. I have high speed fans on demand.
Engine RPM Fan 1(Front) Fan 2(Rear)
low/hi low/hi
700 483/679 470/666
1300 795/1093 785/1087
2750 1620/2250 1600/2202
Foretravel Specs:
Pump Output 1600PSI @ 2750RPM
Fan Speed High 2930RPM @ 2750RPM
Fan Speed Low 1900RPM @ 2750RPM
My next thought is: Is the pump turning the correct rpm for my motor(cat 3116)?
My crank pulley and pump pulley are the same 6". That makes my pump run from 700rpm up to 2650rpm.
What is the size of your pulleys and are they different size?
I don't know anything about the Hydraulic Cooling Fans but I have this from David Pedigo
Interesting how many variations of these hydraulic systems are found in Foretravel coaches. My '93 model U280 has two totally separate hydraulic systems. There is no connection of any kind between them. The gear driven pump on the side of the engine drives the power steering system. The belt driven pump mounted below the alternator drives the cooling fans.
My cooling fan hydraulic system is simpler than Pat's. Looking at his diagram (above) my system does not have the high/low solenoid valve or the star control relief valve. My fans turn any time the engine is running. Fan speed is determined solely by engine RPM. As engine speed increases fan speed increases. Seems to work fine - we have never had any overheating problem (radiator is still original). Knock wood.
Good Morning,
Chuck, my system is like yours. My power steering pump is shaft driven by the air compressor that it is bolts to. My cooling fan pump is belt driven from the CAT 3116 crank. The pulleys on crank and pump are 6", that means the pump runs at engine rpm(700-2650). You will have a pressure relief valve some where. My brother had a 93 U-240 and it did not have a hi/low valve. It had one big fan. My fans run about 700 rpm slow, I have had this problem for years. I can keep the temps under 210 most of the time, but going thru Albuquerque, NM in August is a problem.
Chuck,
Our 1993 U300 with the Detroit also has a direct drive PS pump with separate reservoir with the pump located at the opposite end of the engine. The radiator fans/pump are belt driven off the crank pulley.
Pierce
In Reply #9 up above (posted a year ago) I have links to the tech sheets on the V10 pump used in my coach. I think they mentioned something about an internal pressure relief valve in the pump.
I'll have to look at the size of my crank pulley versus the drive pulley on the pump - see if they are the same size. Interesting.
Even if the pulleys on crank and pump are the same diameter, does that necessarily mean the fans run at the same RPM as the engine? There may be some kind of variable ratio between the pump speed and the fan motor speed. For instance, 100 revolutions of the pump may only produce 50 revolutions of the fan blades. Something like that... Just wonderin'.
How do you measure the RPM of your fans? When I rebuilt my pump, I bought a tachometer at Harbor Freight to check the fan speed before and after my rebuild. It worked pretty good. I only measured the speed at idle. I wrote it down somewhere...can't find it now. At the time it did not occur to me to measure at higher RPMs. Might put that on my list of future "projects".
https://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html
Since I work on a lot of different coaches- Monaco was built either in Indiana or Oregon- using the same prints but turning out different coaches.
Chuck,
In response to the question about how to check fan speed. FT told me to check at WOT. I use a hand held laser tach. This what I get and the FT specs.
Engine RPM Fan 1(Front) Fan 2(Rear)
low/hi low/hi
700 483/679 470/666
1300 795/1093 785/1087
2750 1620/2250 1600/2202
Foretravel Specs:
Pump Output 1600PSI @ 2750RPM
Fan Speed High 2930RPM @ 2750RPM
Fan Speed Low 1900RPM @ 2750RPM
Pat,
I just remembered this morning that I wanted to check the diameter of the pulleys on my coach, to see if they are the same as yours. Turns out my hydraulic fan pump pulley is 5" and the crank pulley is 6.25" so my pump is running
faster than engine RPM (25% overdriven ?). Interesting tidbit of knowledge to file away for future reference.
Pat, to this novice it seems the pump is the issue.
Any way to check the pressure?
Joe
Be sure that nothing in the plumbing system reduces the line size to less than the pump output size anywhere all the way through and
back to the pump.
For a given pressure, flow will be effected by line size. That would effect fan motor speed.
Chuck, Joe, and John, Good Morning,
Thanks for the checking of the pulleys on your system.
Since the last writing, I changed the filters in the oil tank. There is 3 of them, round medal outside with paper inside. The change made no difference. My grandson sent me a pic of a school bus pressure and flow info chart(included in the post). It looks like the engine and pump on it is running at engine speed.
Joe, I have been waiting for two(2) weeks on Rodney Blackman from FT to help me with pressure and flow info on my system and as of now I have heard nothing, I also have checked back with FT about it and I have heard nothing. The pump maker(sauer/Danfoss) will not give any info due to the fact that they make the pump for FT and tell you to contact the OEM(FT).
John, I agree I think the pump is running to slow. When I first had the problem, FT changed the old pump(John S. Barnes) to the new one(Sauer/Danfoss), also changed the star controller and then told me the problem is/was with the fan motors. I replaced both of them with new ones. I have also changed the HI/Low Solenoid Value, nothing has had any effect on fan speed.
Chuck, Thanks for checking those pulleys. I don't know and would like to know how fast can you turn the pump without damage to anything in the system?
Thanks for all the help, I sure need it, I have been fighting this for a while now.
Pat,
I just Googled and found the document linked below. It specifies the max RPM numbers for the type pump fitted to my coach. My hydraulic pump is model number V10F 1S5T 1C10J 20. Looking on page 7 of the document, I see that my pump has a "ring size" of 5 (5 USgpm). At the bottom of the page, chart says a V10 pump with ring size 5 has a maximum rpm of 3200.
My C8.3 engine has governed HP rating of 285 @ 2400 RPM. Governor break RPM = 2450, and high idle (MAXIMUM ALLOWABLE RPM) limit = 2760. I have never seen over 2400 RPM in "normal" driving, including during full throttle upshifts.
Since my pump is 25% overdriven, at 2400 engine RPM the pump would be turning 3000 RPM (2400 X 1.25). This is near the max pump RPM with a little safety margin for transitory over-speeds, like when I'm using our exhaust brake on steep grades. I try to avoid exceeding 2500 RPM when using the exhaust brake.
Don't know if this answers your question. I assume the fan
motors would also have some maximum RPM limitation.
https://www.appliedfluidpower.com/media/wysiwyg/PDFs/V10.pdf
Thanks Chuck, I also have a Vickers Power Steering pump(v101f1s5t38c4h20r) running on the back side of my air compressor, but my hydraulic FAN pump running off a belt is a replacement for my original John S. Barns pump and it is a Sauer/Danfoss.
Pat,
Update:
I spoke with Mr. Blackman with FT today. He has been out of town in training for a while. He is working on the info that I need about the hydraulic pressures and flow in my fan system. I hope to hear from him again soon.
Pat,
Update: I have been working on getting the pressure and flow data for the hydraulic pump that runs a the fan motors. A lot of the models FT built in this time period use the same pump. This is what I have found:
Tag on pump: 25Aug08 80002642 Sauser/Danfoss
Model Code: DE2R-23PD-AA-104-10-N101-NNN-000-AU-AN-NNN
Example Decode:
DE2: D Series Cast Iron Gear Pump, Two Sections (Tandem)
The order code below provides an example of a two section (tandem)
pump.
A B1 B2 C R S D E F G H J
D E 2 R – 2 3 S H – B B – 1 0 4 – 1 3 – N 1 1 3 – N N N – 0 0 0 – A V – A C – N N N
Code Position Description
DE2R A D Series pump with two pumping sections, right hand rotation
23 B1 23 cm3 displacement on first section
SH B2 13 tooth spline input shaft
BB C SAE B two bolt mounting flange
104 R 1 5/16-12 side inlet, 1 1/16 side outlet on first section
13 S 13 cm3 displacement on second section
N113 D No inlet and 7/8-14 side outlet on second section
NNN E No flow control setting
000 F No pressure control setting
AV G Assembly screws
AC H Standard Nameplate
NNN J No special features, black paint
It is a 2 section gear pump. The front section is 1.37 CID and the rear section is 0.58 CID. There are no flow control valves on the pump. These are fixed displacement pumps, so they output flow is dependent on the pump RPM. According to HydraQuip this pump max rpm is 3400.
(Pump RPM x 1.95 CID) / 231 = Pump GPM
I also found that the crankshaft pulley is for 85-95 chevy #14100594.
I would like to change the crank pulley to a larger diameter, not much just a little. Any one got a different pulley number? The number is on the inside face of the pulley.
Pat
Pat,
Just a thinking question. I understand pump Max rpm 3400, but what is the safe rpm of the fan motors and, or the plastic fan blades. By increasing the pump GPM you possibly start building to much case drain pressure blowing motor seals.
You might look at aftermarket aluminum pulleys for hot rods. Some have different OD sizes.
Mark C.
Good Morning Mark,
Good question and thanks for the response. When I first started dealing with this issue back in June of 2014
My 95 U240 Fan Speed by Engine RPM where
Engine RPM Fan 1(Front) Fan 2(Rear)
700 483/679 470/666
1300 795/1093 785/1087
2750 1620/2250 1600/2202
Foretravel Specs:
Pump Output 1600PSI @ 2750RPM
Fan Speed High 2930RPM @ 2750RPM
Fan Speed Low 1900RPM @ 2750RPM
I don't think there is a problem with fan speeds until they raise above 2930 RPM. Mine are at 2200 RPM. I am sure the fan motors will safely turn much faster than 3000 RPM, but I am like you what about the fan blades. I just want to try a different pulley combination, now both crank and pump are the same about 6". I don't know how big a change to make?!?!
Pat,
Pat,
Another option is to fit an auxiliary radiator up front. "T" into the hoses to/from the heater core and use ball valves to direct flow.
Plenty of inexpensive car radiators out there. Shouldn't even need a fan, as you will not exceed normal engine temperature except when moving. And, you are not paying engine HP to run the hydraulic fan faster.
I wonder if there is enough room to replace the coolant hoses from the back to the front with 1 1/4" of hot water pex? That would reduce the friction loss and flow a lot more to the front radiators. Twice the interior diameter should give about 25% of the friction loss.
Pierce
Yes, should increase flow. May be a lot less labor to install a small 12 VDC pump.
Pat,
From your inspection notes, it looks like you aren't getting high fan speed. If pump and motors good, you might have a pressure relive valve bypassing or your fan speed cartridge bypassing. You should be able to match Foretravels speed specs without modifications.
Mark C.
Good Morning All,
Brett: I have tried the front radiator and it does not work. I will not be wasting engine HP to run the fans at proper RPM.
Mark: I control my hi/low fan speeds with a toggle switch on the dash. I have changed all components (pump, motors, hi/low valve, pressure relief valve ). The only original parts are the hoses.
In 2014 I had ForeTravel work on it. They changed the pump and the star value(pressure relief valve) with no change. They sent me home saying it was the fan motors. I changed them out with new ones from Italy($2500 just for motors.) with no change. I originally had a John S. Barns Hydraulic pump. FT changed it out with my current Sauser/Danfoss pump. All other parts are the same as original. Maybe the pump??? FT does not have pressure(PSI) and flow(GPM) data, without that info you cannot dianoise the system.
I am thinking maybe the new pump needs to turn faster than the old one. I do know that most of the FTs fan speeds are about 2700-3000RPM. I know that on Chuck's 280 the pump pulley is smaller(5") than the crank pulley. I am thinking about using a 5" pulley on the pump and removing my old 6.25" pulley, then check fan speeds.
Pat
Don't know about all models but U300 have one installed down low on the left side by the engine. Andy's U300 had one that didn't work but either fixed or replaced it. Friction loss in a hose is like hull speed on a boat. Once you achieve a certain GPM, you need more ID to flow much more.
Pat, Brett and others have installed a front radiator with success. VW Vanagons, Porsche, others have only the front radiator and never have a problem cooling. The Vanagon even has a washer in the front to restrict the flow so there is more complete heat transfer up front.
Pierce
Pat,
The system can be troubleshot.
1 If you are using original type motors, system pressure is 1600psi at high idle. This should be check at normal operating temperature.
2 Then it's a matter of GPM or flow. Sauer Danfoss should have a chart like the bus chart for the pump. It's to bad FT hasn't supplied this.
3 You are correct. Given your problems, you're thinking correct. Pulley size!
I work on equipment every day. You need a very good 2000 psi gauge and I would recommend a flow meter. Might be able to rent one or find a mechanic with one. A 4-40 GPM should work. Something like this.
https://www.amazon.com/Hedland-H801A-075-Flowmeter
Mark C.
Pat,
Forget to mention. Pressure and flow to motors would have to be checked on high fan speed. The high - low soleniod causing oil to return to tank.
Mark C.
That's a LOT of plumbing. The AC system does it, so it is doable.