Shop Vac Suction at Hydraulic Fill Port?

Fallon

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Are you thinking to leave an air gap at the fill port, where the shop vac hose would be? Or to leave the breather vents open? Where are those on a Kioti DK40 SE if you happen to know?
I had a few finger sized holes in my tape job holding the vacuum onto my Grand L. If your vent is smaller than 1 finger (almost guaranteed) the shop vac will still pull enough vacuum to prevent a leak. The combo fill port & vent is convenient in thoery. But has no lip or hose to stick the vacuum nozzle over. Your only option is a 2nd person or taping the nozzle to a flat dirty surface. Less of an issue if the car is on & trying to suck itself to the transmission. But that might come loose as the vacuum decreases when you open the filter or drain at the bottom.

Fun science project for kids or enquiring minds... take a 5 gallon bucket with a lid. Put a drain plug sized hole in the bottom & fill it with water (plug the hole with tape or a finger or something). Hook up a shop vac to the pour spout on the lid. Turn the vac on & unplug the hole at the bottom. Start cutting a bigger & bigger 2nd hole in the lid. I'm guessing you could get to a dime sized hole before the bottom one starts leaking with most shop vacs.

1 square foot or so (guess for bucket upening) is 144 square inches. Times 0.1psi (guess) gives you 14.4 pounds of force pushing up through that hole in the bottom. More vacuum gives you a lot more force. More than a psi or 2 of vacuum would crush your bucket, or seals on your transmission, so it's good a shop vac won't get much actual vacuum.

Fun science teacher experiment. Tell your class anybody who can suck water up a straw/hose over 32' can skip class for the rest of the year. Absolute vacuum won't support more than a 30' water column or something like that (varies on altitude & air pressure as well). An nobody can suck that hard anyway much less get a real vacuum pump to do it.
 

Industrial Toys

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I would consider having to clean the shop vac of oil, if some got in there to be a worse job than cleaning the machine or floor.

Getting oil out of the hose ribbing would be near impossible and now dirt will stick to it like shake and bake.

It's like funnels. I mark some, water only, or oil only, because it's not easy to clean oil off plastic,
 

Captain Dirty

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See my post Here. Clear tubing acts as a sight gauge to show if any fluid is being sucked. K0ua has reported merely blocking the vent to hold the fluid in.
 

BackRoad

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I've done it multiple times with no hydraulic fluid sucked into the vacuum.

My vacuum hose end is larger than the hydraulic fluid fill hole, so I use a short plastic funnel stuck into the fill hole (it does not reach down into the fluid) and stick the vacuum hose end into the funnel to make a seal. Vacuum suction keeps the hose tight in the funnel.

Other than what is in the filter, likely less than 1/4 cup of additional fluid gets spilled into the drain pan while swapping filters (the new one is ready to screw back on immediately, and it might be 10 to 12 seconds at most for the swap to get back on hand tight).

The vac applies sufficient suction to hold back fluid when you remove the filter...especially handy when replacing a Kubota Transmission Filter in between hydraulic fluid replacement hours.
 

Cycledude

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I haven’t attempted it yet but my dealer told me one of his customers ruined his wife’s vacuum cleaner attempting it. He said the biggest mistake was having the vacuum sitting on the floor with a short hose, he recommended a longer hose that goes up quite a ways before returning to the vacuum so the oil can’t get into the vacuum motor, he says they use the vacuum method with a shop vacuum all the time in his shop without any problems.
 

Industrial Toys

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I own an el-cheapo compressed air powered vaccume (venturi) thing that I always use to suck dirty stuff, fuel tanks or explosive fumes. I have rarely used the bag it comes with but often put a hose on the outlet. I'm sure HF has them. A ten inch long or so pipe maybe one ich dia. with a pistol grip and air trigger. Maybe ten bucks on sale.
 

beenthere

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No way that oil can be sucked into the vacuum hose, if just attached to the fill hole.

So many posts here showing fear of oil in the hose and/or in the shop vacuum that are just not possible.
 
  
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Rhino35

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Thanks for all the advice and real world experiences. This forum is a great resource for handy tips and general all around reassurance this isn't a zany idea.

I like the "I use a short plastic funnel stuck into the fill hole (it does not reach down into the fluid) and stick the vacuum hose end into the funnel to make a seal. Vacuum suction keeps the hose tight in the funnel." idea. That beats duct tape.

I also like the advice to keep the shop vac higher than the fill hole so IF some fluid gets drawn up into the shop vac hose it likely wouldn't migrate all the way into the shop vac itself.

I'm going to do this in the next couple of weeks. I'll post pictures of my garage ceiling dripping with hydraulic fluid and my shop vac after it explodes *grin*.
 
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Ddh1961

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Worked great for my LS MT225E a few weeks ago. Left a film of hyd oil in the shop vac’s hose, but I just let it sit for a few days with the hose pointed down and a rag stuffed in the end and the hyd fluid ran out. Have used the vac a few times since and it still works great. It’s not an urban myth, it really works. I saw it on a YT video, done by a guy doing his 50 hr service on his LS. Only lost the oil in the filter, and it sure beats cleaning up a couple of gallons of hyd oil off your shop floor! 👍
 
  
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Rhino35

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Okay! I tried this suction trick with the assistance of my father-in-law yesterday! The good news is my 350 hour old hydraulic fluid looked great. I paid about $900 to my dealer for the 50 hour service, which is everything gets changed. It was a very light brown - looked like new engine oil. Guess those filters work pretty well! And as far as any "shearing of the molecules" might go from time in service usage or heating that could reduce its effectiveness, let me attest that stuff is slippery!

I know the hydraulic fluid color because it got all over the place.

To start my hydraulic fluid filter journey of discovery I took out the shop vac bag and the conical pleated filter. Put the shop vac on a step ladder on top of the bush hog to elevate it and used bungie cord to secure it . FIL (Ha! Father in Law, changing FILters, too bad his name isn't Phil) ensured the shop vac hose stayed put and also held the hose up so any fluid that might get sucked into it would have a lot of gravity to overcome to get into the shop vac. The shop vac hose fit perfectly into the hydraulic fluid fill port, and he didn't think it cracked the seal during my ensuing flail-ex, so he concluded in the future it would not need attending. Because it apparently fit so well I didn't use a funnel or duct tape.

I put a finger wipe of fresh oil on the rubber gaskets of both filters. Loosened the big system filter just a tad, then FIL started the shop vac. With suction going I began spinning off the filter. Before it was unthreaded it started dripping some around the edges and suddenly my hand was coated with fluid and super slippery. I did not think this through and have a basin of some kind to lay the old filter in so I just put it down on my concrete shop floor. Now fluid is dripping pretty good out of the filter attachment point - the shop vac is not holding it all back. I tried to pick up the new filter but it squirted away towards the bush hog and FIL. I yelled for him to kick it back towards me, which he did. Then somehow with my oil coated hand I picked it up (it is pretty wide) and spun it on. About two quarts lost.

The hydrostatic transmission filter I noted from print on its side is supposed to be changed every 200 hours. Well, okay, so that went 350 hours too. With the shop vac going it lost very little fluid - maybe half a cup.

Did the suction trick work? I'm convinced it helped. I think without it holding back full flow during my keystone cop routine under the tractor instead of two quarts I'd probably have lost two of the eleven gallons.

My progress towards "Country Man Certification" took one step forward for attempting this, but unfortunately two steps backwards for the preventable buffoonery I demonstrated!

Rhino
 
 
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