Nige
Senior Member
Have you determined what grade of oil is in the hydraulic system right now?
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CAT 299C - Hydraulic Oil Pre-Heat Possible?
- Thread starter HighFlyerAK
- Start date
92U 3406
Senior Member
We put 0W-20 TDTO in every skid steer we repaired or serviced unless the customer specified otherwise. We'd see temperatures of -35°C and never had any real issues. Even cold starts in the yard you'd never hear the pump making cavitation noises and the machines were suprisingly responsive when cold.
Good news is TDTO 0W-20 covers a very wide temperature range in a skid steer. I don't have SIS anymore so I can't quote the exact numbers but in that region it was good year round.
Good news is TDTO 0W-20 covers a very wide temperature range in a skid steer. I don't have SIS anymore so I can't quote the exact numbers but in that region it was good year round.
Welder Dave
Senior Member
I wonder if a battery heating blanket or pad would work or a plastic drum heater. The BriskHeat drum heaters come with an adjustable thermostat. McMaster-Carr also has some rectangular heating pads that are suitable for plastic tanks if you scroll down in the link below. Probably have to get a temperature controller as well.
Car Battery Heaters Protect Batteries From Cold Weather Damage | PTI (phillipsandtemro.com)
Silicone Rubber Plastic Drum & Bucket Heater (DPCS) - BriskHeat
plastic bucket heaters | McMaster-Carr
Car Battery Heaters Protect Batteries From Cold Weather Damage | PTI (phillipsandtemro.com)
Silicone Rubber Plastic Drum & Bucket Heater (DPCS) - BriskHeat
plastic bucket heaters | McMaster-Carr
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ThreeCW
Well-Known Member
As 92U 3406 suggested, running the right viscosity hydraulic oil for your ambient temperature range will likely be your best option and a hydraulic oil preheater should not be required. The rated ambient temperature range for the CAT TDTO Cold Weather 0W-20 is -40 C to +40 C (-40 F to +105 F) with a pour point of -54 C ... that sounds like a pretty good product for your Alaska application.
You also mentioned in an earlier post that you do not envision running your equipment below -20 C. If that is the case, you might be able to get away with using CAT HYDO Advanced 10 (SAE 10W) which has a rated ambient temperature range of -20 C to +40 C (-4 F to 104 F) with a pour point of -39 C. With those specs, this hydraulic oil might be just on the edge of your operating window. I am successfully using the CAT HYDO Advanced 10 in my CAT 242B skid steer in Southern Alberta down to -25 C, but my skid steer is kept in a heated building (+5 C) in the winter.
Find attached product data sheets of the above mentioned hydraulic oils and the Hydraulic Oil Selection Charts from CAT publication SEBU6250-28: Caterpillar Machine Fluids Recommendations.
You also mentioned in an earlier post that you do not envision running your equipment below -20 C. If that is the case, you might be able to get away with using CAT HYDO Advanced 10 (SAE 10W) which has a rated ambient temperature range of -20 C to +40 C (-4 F to 104 F) with a pour point of -39 C. With those specs, this hydraulic oil might be just on the edge of your operating window. I am successfully using the CAT HYDO Advanced 10 in my CAT 242B skid steer in Southern Alberta down to -25 C, but my skid steer is kept in a heated building (+5 C) in the winter.
Find attached product data sheets of the above mentioned hydraulic oils and the Hydraulic Oil Selection Charts from CAT publication SEBU6250-28: Caterpillar Machine Fluids Recommendations.
ThreeCW
Well-Known Member
We are limited to 4 attachments in this forum, so in this post I have attached for your reference the full CAT publication SEBU6250-28: Caterpillar Machine Fluids Recommendations.
Nige
Senior Member
As other posters have confirmed I think you are creating a solution to a problem that doesn’t exist. Change the oil to the appropriate grade for the ambient temperature and the symptoms of slow hydraulics when cold will most likely either go away completely or at least become something that is manageable.
HighFlyerAK
Well-Known Member
I understand. No need to re-invent the wheel as long as it works. I can live with that.
In that case, Thank you to everyone for shedding light to this question I have looked way too long for an answer!
I really appreciate it!
HighFlyerAK
Well-Known Member
ThreeCW, I really appreciate the help and can‘t see why I wouldn‘t go the ‚safer‘ oil and change to CAT TDTO Cold Weather 0W-20W.
Learned something I didn‘t know the answer to for a long time.
Again, very much appreciate your time and input!
Nige
Senior Member
Another titbit of info. If you have the engine coolant already warmed up using a block heater before starting you can stall the hydraulics at low-to-medium engine RPM against the main relief valve by using either the lift or the tilt control. This can be done from a couple of minutes after starting. The heat generated will warm up the hydraulic oil far faster than the numbers you quoted a few posts above.
HighFlyerAK
Well-Known Member
Nige!
Are you referring to moving the controls or...? Would you care to elaborate some more please?!
The only thing I can think of what sounds similar to what you describe is what I read in the CAT cold weather operations part. Which mentioned to move the lift arm/attachment tilt ever so slightly and in small increments.
What do you mean with „stall the main relief valve“?
I would love to reduce the warm up time (in accordance with CAT procedures)!
Stall means to hold the control valve all the way to the end of the stroke, the hydraulic oil will be forced through the relief valve turning the power into heat. "This can be done from a couple of minutes after starting" means don't do it until the engine has been running a couple of minutes already. I'd move all the functions smoothly in that time, and NOT hit the end of any stroke. I say smoothly, Cat said small increments so I guess I'd follow that for the first minute, then move the controls at full speed (still lower medium engine speed, and not hitting the end) for another minute, and then over the relief if you're going to do that.
HighFlyerAK
Well-Known Member
THIS is excellent! I have never heard of it (no surprise there).
Follow up question, which might be related.
If the engine is running, but the hydraulic/parking brake switch is not activated/deactivated, will hydraulic fluid circulate less than when the switch is pressed and the two red lights (hydraulic/parking brake) are not illuminated?
Or does it not matter, AND forcing the fluid through the relief valve is the way to go! Which I am perfectly fine with.
Am I holding the control against the ‚stop‘ for a certain length of time or only for short periods?
Thank you for explaining in great detail Delmer!
Nige
Senior Member
Here's how I would do it. As Delmer says it's all about converting pressure/flow into heat as the oil literally sprays though the needle of the relief valve while it is being held open.
1. You said you are using a heater to get the coolant to 85 Deg before starting. Start the engine and let it run at low idle for a couple of minutes.
2. Increase engine RPM to somewhere no more than mid-way between low idle and high idle RPM.
3. Slowly pull the tilt control to tilt the bucket backwards. When the bucket reaches full tilt back hold the lever in that position for maybe 1 minute and don't let the RPM change too much. At the end of that time return the control lever to the neutral position and reduce the engine RPM down to low idle for maybe 30 seconds.
4. Repeat step 3 but using the bucket control in the "power down" position. CAUTION: This will lift the front wheels off the ground.
5. Keep repeating Steps 3 & 4, allowing the engine to go to low idle RPM in between each one, until the oil has significantly warmed up. It won't take very long. Note the oil temperature.
6. With the engine just off low idle RPM, raise the bucket slowly to full height and lower it again. Repeat a couple of times. The last time you do it stop the bucket about half-way down.
7. Repeat Step 6 using the tilt control. Full tilt forward to full rackback a few times. Lower the bucket to the floor.
8. Check the hydraulic oil temperature. It will likely have gone down due to the cold oil coming from the cylinders dropping the temperature in the tank. Repeat Steps 2 thru 7 as necessary.
The reason you use tilt back/power down is that the mechanical forces on the cylinders are less using those functions than they are when using tilt forward/bucket raise. This is down to the area in the cylinder on which the oil pressure acts. One way it acts over the whole area of the piston, the other way (the one you use during this procedure) it acts over the area of the piston minus the area of the rod. The same procedure is used when testing/adjusting the setting of the main relief valve.
Let us know the results.
1. You said you are using a heater to get the coolant to 85 Deg before starting. Start the engine and let it run at low idle for a couple of minutes.
2. Increase engine RPM to somewhere no more than mid-way between low idle and high idle RPM.
3. Slowly pull the tilt control to tilt the bucket backwards. When the bucket reaches full tilt back hold the lever in that position for maybe 1 minute and don't let the RPM change too much. At the end of that time return the control lever to the neutral position and reduce the engine RPM down to low idle for maybe 30 seconds.
4. Repeat step 3 but using the bucket control in the "power down" position. CAUTION: This will lift the front wheels off the ground.
5. Keep repeating Steps 3 & 4, allowing the engine to go to low idle RPM in between each one, until the oil has significantly warmed up. It won't take very long. Note the oil temperature.
6. With the engine just off low idle RPM, raise the bucket slowly to full height and lower it again. Repeat a couple of times. The last time you do it stop the bucket about half-way down.
7. Repeat Step 6 using the tilt control. Full tilt forward to full rackback a few times. Lower the bucket to the floor.
8. Check the hydraulic oil temperature. It will likely have gone down due to the cold oil coming from the cylinders dropping the temperature in the tank. Repeat Steps 2 thru 7 as necessary.
The reason you use tilt back/power down is that the mechanical forces on the cylinders are less using those functions than they are when using tilt forward/bucket raise. This is down to the area in the cylinder on which the oil pressure acts. One way it acts over the whole area of the piston, the other way (the one you use during this procedure) it acts over the area of the piston minus the area of the rod. The same procedure is used when testing/adjusting the setting of the main relief valve.
Let us know the results.
HighFlyerAK
Well-Known Member
I will do exactly that and document the time it takes to get to 50°F in comparison. Thank you Nige!!!!!
heymccall
Senior Member
I run TO4 soec 10w in all my stuff. On a TL150, if you don't warm the hydraulics a bit before raising the revs over a quarter throttle, in 10°F weather, the pilot filter collapses.
treemuncher
Senior Member
I know this thread is close to a year old but I'm researching putting a heater to my hydraulic tank on my excavator's pony hydraulic system to speed up my warm up times. The brush cutter system hydraulic tank holds nearly 3 barrels of oil (poorly designed system IMO). If it's down in the teens at night, I can expect a lost hour waiting to heat my cutter hydraulic system to anything close to operating temperatures.
My Lamtrac has an Eberspacher diesel fired coolant pre-heater system installed with a heat exchanger in the hydraulic tank and engine block. This system heats engine coolant via the Eberspacher, pumps it via a 12v coolant pump to the hydraulic heat exchanger and then to the engine block and back to the heater again. This works very well to get the machine to operating temps much quicker than using the engine alone. The controller is also programmable so that I can arrive on site to a machine that has been warming during my commute if my timing is good.
Heat exchanger for the hydraulic tank: https://thermex-systems.com/fluid-fuel-warming-systems/heatprobe-fluid-warming-systems/
I'm thinking about adding one of these systems with an affordable Chinese knock-off heater from Ebay. The heat exchanger will be the most expensive component but a system like this requires no more electricity than a 12v battery and is great for remote work areas.
My Lamtrac has an Eberspacher diesel fired coolant pre-heater system installed with a heat exchanger in the hydraulic tank and engine block. This system heats engine coolant via the Eberspacher, pumps it via a 12v coolant pump to the hydraulic heat exchanger and then to the engine block and back to the heater again. This works very well to get the machine to operating temps much quicker than using the engine alone. The controller is also programmable so that I can arrive on site to a machine that has been warming during my commute if my timing is good.
Heat exchanger for the hydraulic tank: https://thermex-systems.com/fluid-fuel-warming-systems/heatprobe-fluid-warming-systems/
I'm thinking about adding one of these systems with an affordable Chinese knock-off heater from Ebay. The heat exchanger will be the most expensive component but a system like this requires no more electricity than a 12v battery and is great for remote work areas.
I just don't like the idea of a cheap chinese heater in a situation like this. Since you're in TN so hopefully not needing this 90 days a year, I'd come up with a hot air system that runs on propane for 15 minutes, or even better would be system that heats with your trucks coolant, or steam, with a heat plate bonded to the bottom of the tank for coolant, or just piped and somewhat shielded for steam to heat the tank directly.
Nige
Senior Member
Is piggy-backing a third heat exchanger to the existing Eberspacher system to supply hot coolant to the pony hydraulic tank a possibility.?
treemuncher
Senior Member
If I put in a propane unit, I need to provide another fuel source. That solution is off the table due to logistics. A generator and electric heat pad would be preferred before I went to propane. Diesel only for any added heat source for easy logistics. I hooked up another Chinese diesel heater last night to see if it was effective to keep my shop warm. 50'x80' building at 18 degrees overnight and the shop stayed at 45-46 degrees while burning about 1.5-2.0 gallons of diesel over 14 hours. I'm satisfied with that experiment.
That Eberspacher system is on the Lamtrac - my tracked mulcher. I'm considering putting the same thing on the Komatsu's piggy back system due to the extended warm up times required. The Komatsu never has a problem starting or warming so I don't really need one on that. The hydraulic tank on the piggy back is made of 3/4" plate steel with over 150 gallon capacity and is a huge heat sink that delays warm ups.
I checked further into the cost of the heat exchangers and those run $500-$1k per unit and I will need at least 2. I can come up with alternatives that might be simpler for me and more affordable. The Chinese water heater is around $500 which is much more tolerable than a German unit at $1k-$2.5k. Just because my ex-wife is Chinese does not mean I won't still use Chinese built products. Some are defective and some are good for a long time.