Does the hydraulic oil freeze?

[idaho04]

I know I could post this in TBN but I'm sure you guys will know this too. The hydraulics stopped working on my F1900 tractor. I wonder if it is because it is too cold, but I thought oil does not freeze, at least motor oil doesn't. I recently changed the hydraulic oil just to make sure there is no moisture in there. It has been between 5 and 20 F for last 10 days here in No ID.

[Bird]

I wouldn't say it actually "freezes";i.e., become a solid, but it can get so thick that it won't circulate or pour. In some cases, you simply have to start the tractor and let it run at a fast idle to "warm up" for quite some time. And that can go for both motor oil and hydraulic oil. You know early bush pilots in Alaska used to drain their oil after landing and take it inside to get it hot to pour back in the engine the next day. And one of my brothers used to put a smudge pot under the crankcase of an 18-wheeler to warm the oil before starting the truck. [img]/forums/images/icons/tongue.gif[/img]

[Pat]

Typical engine oil and most other oils will, when cold enough, shatter like glass when struck a blow. The oil in your shocks will be so thick at -40 (F or C, take your pick, it doesn't matter at all) that it will virtually not pass through the orifice rendering the shock the equivalent of welding the frame to the axle.

I spent three years at Minot, ND during my Strategic Air Command phase. "Peace is Our Profession" was the public PR slogan but behind the scenes my comrades would say, "Nuke 'em till they glow in the dark so we can see to shoot 'em at night!"

My personal low was -47F. Things get weird when it gets real cold.



[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[Bird]

Pat, fortunately I don't know a lot about real cold [img]/forums/images/icons/tongue.gif[/img] ; -20F is the coldest I've been out in, and my Chevy pickup started and ran OK with no block heater that day. I would assume that any liquid would freeze if it got cold enough, but don't know that to be a fact. I probably should have been more specific in my response to the original post. He mentioned temperatures of 5 to 20 and I know his hydraulic oil wouldn't freeze solid at those temperatures although I would expect it to be a little "thicker". [img]/forums/images/icons/laugh.gif[/img]

[DUMBDOG]

Yes, it is colder in Minot than 100 miles south of there. But it sure gets cold here also. That is why we had down to Florida in the winter, seems like the cold is no longer fun any more.

Getting into a cold vehicle that rides like a lumber wagon, speedometer does not work along with a defroster that blows cold air. By the time everything is working you are at your destination. Have started driving and had to get out and check the tires because it was handling like it had a flat, but there were just frozen and had to be warmed up like everything else.

[Bird]

Yep, Dave, I really like "cool" weather; 50s and 60s ideally and don't mind a little colder too much as long as it stays above freezing. But I don't care for sub-freezing temperatures at all. And even though we don't get your kind of cold, I know what you're talking about with the tires. Remember when bias ply nylon tires were about the best thing you could get? The worst was the '73 Winnebago we had. On a cold morning, those tires would really rattle the dishes in the cabinets the first 5 or 10 miles.

[Pat]

Bird, As regards REAL cold, you don't really need and shouldn't want to experience it. When the temp gets down below -40 (and even warmer temps) things can get really weird. I think the vapor pressure of Propane goes to zero at about -47F so when you open the tank valve nothing comes out.

At temps above 0 degrees F single weight crank case oil might get a bit thick but it doesn't get into Twilight Zone behaviors. The 5F to 20F example/issue is not a result of super thick hydraulic oil.

A strange case of a cold (supercooled) liquid. Plain glass (window glass) is not a solid. It is a supercooled liquid. Glass flows like other liquids just really really slow as it is so thick in viscosity.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[Pat]

Ddog, I recall driving air cooled VW vehicles in Minot. I could drive all the way from the SAC base to town (15 miles) and the best the defroster would do with all heat diverted to the windshield was to make the ice on the inside of the windshield within about 4-6 inches of the defroster outlet more transparent and somewhat easier to scrape.

The needed crew complement for a VW was the driver and starter helper/scraper. The starter helper/scraper sprayed the starting fluid into the air intake while the driver started the vehicle and then repetively scraped the frost off the inside of the windshield as you drove. Your breath constantly created frost on all the glass.

When having difficulty driving away from the curb after parking for a couple hours I would get out and give the break drums each a good whack or two with the tire iron to break the thin film of ice that formed between the brake shoe and the drum from blowing snow melting in contact with the warm drums from stop and go driving in town.

We drove our MGA roadster (side curtains, not windows) for a couple years before we sold it and got a car with roll up windows (Sunbeam Tiger as seen on TV's "Get Smart.") It had a heater and several other amenities with which the MG was not equipped.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] In cold weather the hydraulic oil gets viscous enough to where the atmospheric pressure acting on the surface of the hydraulic oil reservoir cannot overcome the losses in the PUMP INTAKE PIPE, and the pump starves. Often, hydraulic pumps are mounted on the side of the engine, and it's quite a "pull" to get the oil from the sump to the pump inlet. [img]/forums/images/icons/tongue.gif[/img] YEEK! A Sunbeam Tiger.....shades of 1967! One of the roomates I shared an apartment with had a red Tiger. [img]/forums/images/icons/cool.gif[/img]

[Pat]

CJDAVE, Did your roomie have gold Chrysler stars on the front fenders of his '67? Mine was a '66 and was Forest (BRG) green and was purchased prior to the Chrysler purchase. When Chrysler bought a bunch of Routes Group stock (Routes Group is like GM in England) they forced Sunbeam (one of the Routes Group brands along with Talbot etc.) to drop the racing program support for the Tiger. Prior to that debacle the Tiger was begining to go places in the sports car racing circuit.

I had all the dealer options installed as soon as the obligatory 1000 mile breakin was accomplished (hardly more than a long weekend.) Vic Edelbrock designed a high rise aluminum intake manifold that would put a Holley 4 barrel progressive opening racing carb under the hood without having to bubble or scoop the hood. Tuned headers with dumps, Ford twin point racing distributor, high performance Mustang cam and solid lifters all came in boxes marked Sunbeam and were dealer addons so the beastie was still "stock." Not bad for a little two seater British sporty car. It would do an honest 165+, as advertised. I drove it Minot in the winter on ice and snow and never had a control problem (except for one time.) I punched it too hadr too soon on less than perfect traction and got wheel tramp which litterally ripped one of the shocks out of the car by the roots.

Oh by the way, on "Get Smart" with Don Adams, a spy spoof comedy series, the Tiger was supposed to have a machine gun under the hood that would come up through doors in the hood for use. There is no way to do that as the engine fills the available volume with no waste space. You'd be lucky to have room for a Derringer. With proper rearend ratio and cheater slicks you could turn 108 in 13 flat. Prety good for its time.


[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]