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View Full Version : Hydraulic Engine Hoist - Trouble in River City.



gnm109
08-15-2010, 12:40 PM
I used my 2 ton Taiwan folding engine hoist last week to lift my 80 gallon vertical Industrial Air Products compressor (Combination USA and Canadian-built). I did a bad thing when I was putting it away. It has a valve handle with a threaded rod on it and I inadvertantly screwed the handle all of the way out. Now why did I do that?

There was no load on the hoist but the arm was still 3/4 of the way up and when the handle came out, it spouted a lovely column of oil that went about five feet all the way out the door. Took me a half hour to mop it up.

Now, the cylinder won't move. I suspect that it's got an air lock inside. It's worked perfectly up to now, some ten years. I tried adding hydraulic oil to the cylinder but no response.

Do any of you know of the correct method to refill one of these from scratch? I suspect that I'll have to drain it completely and exercise the piston in some way. It will be easier to work on if it's on the bench. I'm going to remove the cylinder so that I can attempt to prime it again and purge the air.

If I can't get it working, I'll have to toss it and get another one. This one is rated at 2 tons and H.F. had replacement rated at 3 tons for $49.95.


The pictures show where the parts are located. Thanks in advance for any suggestions. :)

Picture of the unit.

http://i144.photobucket.com/albums/r188/gnm109/EngineHoistAA-1.jpg

Handle, drain and filler locations.

http://i144.photobucket.com/albums/r188/gnm109/EngineHoistA.jpg

Black_Moons
08-15-2010, 12:57 PM
errr, Im almost sure the cylinder should be rated for more then 2 tons. Unless you mean the entire unit.. Not sure id buy a $50 engine craine!

My cylinder (on a similar 2 ton unit) is rated 10tons iirc. Or was it 16? Something really high like that anyway. Definately not 2.

gnm109
08-15-2010, 02:56 PM
errr, Im almost sure the cylinder should be rated for more then 2 tons. Unless you mean the entire unit.. Not sure id buy a $50 engine craine!

My cylinder (on a similar 2 ton unit) is rated 10tons iirc. Or was it 16? Something really high like that anyway. Definately not 2.


Hmmmmm, a comment in re capacity and my crane purchase.....OK. It was a hoist from a company that's no longer in business in California AFAIK. They sold higher-end name brands and also some Taiwanese equipment. They were a predecessor to Harbor Freight, in fact, H.F. drove them out of business. This hoist was $250 when I bought it a long time ago. and it's a nice one with removeable legs that store on the frame.

The arm is marked, 1/2, 1, 1-1/2, 2 tons. Before I scraped the peeliing sticker off of the cylinder a few years ago, IIRC it was rated at 2 tons. I know I've pulled a Chevrolet 350 and transmission out in one piece with it and also lifted half a lathe and an 80 gallon air compressor. So much for capacity.

By the way, where can you get a $50 engine crane.....and why do you need a 10 ton ram in a 2 ton hoist.....? But I digress.

As to the cylinder, since you didn't ask, I fixed it this morning by removing it and placing it horizontally in a bench vise. When I removed the relief valve screw, the one with the handle, I got a charge of air out. It sounded similar to a camel passing gas. I know that sound since a fellow near me has some camels on his ranch and that's what it sounded like.

Immediately after the air was released, it started working. I then raised it all the way vertically and filled the cylnder to the filler hole. All is now well, but I was worried for a while there.

Thanks anyway.......

The Artful Bodger
08-15-2010, 04:41 PM
Pleased to hear you got it going again!

The reason for needing a 10 ton ram in a 2 ton hoist is because of the leverage in the machine.

John

Doozer
08-15-2010, 04:56 PM
Find that little steel ball that came out when you unscrewed the release valve all the way. It's on the floor somewhere.

--Doozer

Black_Moons
08-15-2010, 04:58 PM
Pleased to hear you got it going again!

The reason for needing a 10 ton ram in a 2 ton hoist is because of the leverage in the machine.

John

Exactly. If there was any '2 ton' marking on the ram, It was for the hoist itself, And not the specs of the ram.

Ie 'This ram is part of a 2 ton hoist' markings.

duckman
08-15-2010, 06:13 PM
If you had the ram extended all the way out when you filled it thats a NO NO, ok heres what you need to do extend the ram take out the filler plug release the lever and slowly push the ram in, after you clean up the mess, put the plug back in, then your good to go. To make sure that you don't have any air in the cylinder, while you have the assembly out extend the ram turn whole unit upside down release the lever and push the ram in, then extend the ram again remove the plug and proceed as before.

gnm109
08-15-2010, 06:21 PM
If you had the ram extended all the way out when you filled it thats a NO NO, ok heres what you need to do extend the ram take out the filler plug release the lever and slowly push the ram in, after you clean up the mess, put the plug back in, then your good to go. To make sure that you don't have any air in the cylinder, while you have the assembly out extend the ram turn whole unit upside down release the lever and push the ram in, then extend the ram again remove the plug and proceed as before.


Yeah, I did that after I got it working again. I took it all the way down and removed the excess. It's working fine now. Thanks.

.

gnm109
08-15-2010, 07:57 PM
Find that little steel ball that came out when you unscrewed the release valve all the way. It's on the floor somewhere.

--Doozer


LOL, that's a good point. I'm pretty sure that you're right on that. I'm going to take the cylinder off again tomorrow and refit a new ball bearing. I have a selection of them. IIRC, it's probably about a 3/16" BB.

Oddly enough, I had the same problem a few years ago when I was trying to stop a leak on my 20 ton hydraulic press. I discovered that when I had it apart on the bench to fix the leak, I lost the ball bearing. I laster found that one on the floor. That one was a 3/16" BB so that's where I'll start. The relief valve has a tapered end which works without a ball bearing but I'll have to put a new one in, obviously. I don't think I'll find the one for the lift, though, since it got "launched". Thanks for the reminder.

So, anyway, what I learned today about getting the cylinder working again is to bleed the air out with the cylinder lying down. Then it can be topped off when vertical again to the filler level with the ram down.

So much machinery, so little time. :D