Hi! I am trying to find a way to pre-heat the hydraulic oil on my 299C skid steer. Since the hydraulic oil tank is not metal, a lot of options are not an option unfortunately. I do have a block heater, which works very well and surprisingly quick. I can literally watch the coolant temp rise on the service display when I have it plugged in. Running the machine occasionally up here in AK in the winter is rather hard on it (in my opinion). ANY ideas or experience for cold weather operation is greatly appreciated.
What grade of oil are you using right now in the hydraulic system..?
And what is the coldest temp you operate it in? I'd think you could attach a silicone heating mat to the plastic tank as long as you get one with low watt density and attach only to the tank where it will always have oil inside. Or attach a higher watt density heater to a piece of 1/8" aluminum and attach that to the tank. Silicone caulk with aluminum flakes will be a decent heat transfer compound for this application (unfortunately you'll have to mix your own)
I honestly don‘t know. It has been a while since I bought the last 5 gallon bucket of Heavy Duty hydraulic oil. I will have to check.
It would be safe to say that I won‘t run the machine unless it has at least around 0°F/-20°C or warmer. We do get longer lasting waves of -10° to -15°F, but so far I haven‘t seen a reason why I would have to run my equipment at such temperatures. When you suggest ‚low watt‘, what Watt do you have in mind?
Based on what the Canadian members have recommended for use in skid steer hydraulics in similar climatic conditions to what you are describing the perceived wisdom is to use a 0W/20 multigrade hydraulic oil. I'll bet that you aren't using anything that "thin".
I agree. Most definitely not. I will look into that first thing Monday. Thank you Nige!
Low enough that it won't melt the plastic I'm fairly sure there are silicone pad heaters that are powerful enough to melt the plastic tank, put those on aluminum sheet that's big enough to spread the heat out, or get a lower watt density one. This came up on a search, "for use on smooth metal surfaces" so I'd put that on a bigger aluminum plate and silicone that to your tank. https://phillipsandtemro.com/solutions/specialty/pad-heaters/
Plastic hydraulic tanks and fuel tanks for that matter seem like the opposite of progress. I thought steel hyd. tanks help to dissipate heat. I got the hyd. oil heater option on my skid steer. It threads in a bung on the tank just like the drain plug. Some machines don't even have a drain plug on the hyd. tank. I think I read where hyd. oil heaters use half the watts of a water heater element. Plastic tanks would be horrible if you had a fire on the machine.
So you have a factory hydraulic oil tank heater installed? Any chance you would have a part number perhaps? Unless it is a different brand/model of course. Still interesting to know that such thing exist from the factory! Looks like there could be a few available ‚openings‘...
I can follow your logic. The only argument I would have against that solution would be the lack of a large enough flat surface. But I might be wrong about that.
I fully agree with you Welder Dave! I would love a metal version of a hydraulic tank, especially heat dissipation could be useful in the summer sometime.
My machine has a steel hydraulic tank. I don't know who makes the hyd. oil heater but it is 3/4" NPT similar to a block heater. Kind of like the ones below but shorter. 2020 Phillips and Temro Catalog (cld.bz)
What type of skid steer is it?!
Not wishing to be controversial here, but why not use a heating pad on a (full) plastic tank? Did nobody else do the boiling a paper cup full of water with a candle trick when they were a kid? I'm not saying it would work, but the theory's good.
A Thomas made in Canada.
But if it didn‘t work, I would have a big mess on my hands and spend a lot of money and labor to fix the mess
A heating pad for oil stuck on the bottom of the tank could work. Kind of like heat tape for plastic water lines.
I have sent a request to HTD Heat Trace, Inc., with a photo and what I was intending to do. The reply was... „Thank you for your inquiry, but we don’t offer a heater for your application. There is not enough surface area for a heater like ours to be able to accomplish what you are looking for.“ Am I really trying to do something so unusual?! Changing the oil twice a year, before and after winter, doesn‘t seem to be very... efficient. (No offense Nige) I just got back from running my skidsteer today. OAT was 30°F, block heater had the coolant up to 85°F by the time I started it. Hydraulic oil was at 30°F. It took 19 minutes to get it to 50°F!
Welder Dave - the heating pad manufacturers I have considered, require metal tanks. Unless there is a company which I am not aware of which specializes in non-metallic fluid containers!?
Have you determined what grade of oil is in the hydraulic system right now?
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.
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
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.
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.
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.
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!
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!
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.
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.
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!
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.
I will do exactly that and document the time it takes to get to 50°F in comparison. Thank you Nige!!!!!
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.
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.
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.
Is piggy-backing a third heat exchanger to the existing Eberspacher system to supply hot coolant to the pony hydraulic tank a possibility.?
I think he's talking about two different machines. Copying the existing system on the other one.
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.
Maybe you just need a proper hydraulic cooler bypass, and tank bypass, so you don't use the cooler or the tank volume when you don't need it.
I wish the manufacturer had thought of those ideas, especially designing the proper size tank rather than just winging it. I've already added a thermostatic bypass valve and a large oil cooler to control my oil temps in warmer weather. Building a tank volume bypass system is a great idea but a lot of work to build into an existing system that I don't rely on for regular jobs. I've got a large amount of work coming up for this machine but I don't use it anywhere near as often as I used to due to more efficient means for most regular jobs. When I have to slam out a lot of really big standing stuff and move debris about, this is the best machine for the job.
The bypass could be as simple as you want it. The return before the cooler run to the inlet with one valve to stop that flow manually once hot. The cooler will have some backpressure to cause the flow to go mostly through the bypass until hotter and thinner. Another option would be a very well sealed blanket around the hydraulic tank, if you're using the thing all week and work long days, it might make a big difference.
I appreciate your input and thoughts but my tank for the PB unit is the back tail swing area. The dark line on the bottom section of the tail swing IS the hydraulic tank from side to side with a 300 hp 8.3 mounted on the top of it. I don't see this insulation as a viable option in brush/timber work conditions to keep a blanket or other insulation in place due to working conditions. I would also have to remove it within the first hour's work after warm up. This pic was of an electrical ROW job where I was only taking out a few select trees in the work path and working conditions were very clean. Most jobs are much more encroached with hazard limbs and pieces of trees everywhere, not to mention the flying debris that also gets kicked up. Here is a little more detail of the tail. You can see the riser portion of the tank where the hydraulic oil cap is on the top. That box is only 12x12xmaybe 24" tall. The rest of the tank is the base piece with a chunk of 3/4" plate for extra counterweight & protection on the bottom of the tank. I've added the thermal bypass valve and the oil cooler seen above. If I was to add another bypass valve at a lower change over temp to keep the circulation at the left side of the tank until warm, that might help but involves a lot of work that I can not justify at this time. The concept of the diesel fired heater still remains my most cost effective and time effective fix at this time. Even if I use the diesel/air heater and direct that to the intake side of the tank, that would be of some benefit but the water/oil heat exchanger would be the most efficient and cost effective solution in the end.
Yeah, figured the insulation would be a long shot. I still think you're overthinking the bypass, if the bypass could be manual, that is, you're the only operator, and only use the bypass for cold starts, then get off and close the bypass once at operating temp. Or close partway to warm the tank for a while, then close completely when the whole tank is up to operating temp. I would want only a minimal bleed flow to the tank, run the return to the intake, leaving the intake open to the tank. I'm thinking that would be cheaper, lower maintenance than a heater and heat exchangers.
Right now, the cheapest and simplest way out appears to be a NC 12v solenoid valve ($25-$40) for the engine's coolant loop going to a tube and shell or plate style heat exchanger ($100-$2k) that would provide the engine's heat to the hydraulic oil via the engine coolant. A 12v solenoid can be operated from the cab. There are no moving parts to the heat exchangers and they won't add heat once the valve is back to closed. The engine will have to heat prior to adding heat to the hydraulics but this would be faster than my typical "bypass the hydraulics" method of heating the oil that I usually have to use. I could live with this and save time. I'll do more research tonight and maybe order parts.