[Caps18]

I am borrowing an engine hoist that rarely gets used (hasn't been used in the last 8 years...), but it seems that it is having problems holding. The arm slowly drops back down after you work really hard to pump it up. Well pumping it seems too easy compared to other jacks I have used.

I have tried to bleed the air out a few ways, and I have filled up the cylinder with hydraulic oil. I am not sure if I have been successful at getting all of the air out. I'm not sure if there is a bubble in the small pump piston from when it got turned upside down. I've tried opening up the release valve and pumping it like the manual says to get the air out.

http://www.ehow.com/how_7880063_refi...-cylinder.html

Is there something else I should try to get this to work?

Thanks

[TigerNut]

Originally Posted by Caps18

I am borrowing an engine hoist that rarely gets used (hasn't been used in the last 8 years...), but it seems that it is having problems holding. The arm slowly drops back down after you work really hard to pump it up. Well pumping it seems too easy compared to other jacks I have used.

I have tried to bleed the air out a few ways, and I have filled up the cylinder with hydraulic oil. I am not sure if I have been successful at getting all of the air out. I'm not sure if there is a bubble in the small pump piston from when it got turned upside down. I've tried opening up the release valve and pumping it like the manual says to get the air out.

http://www.ehow.com/how_7880063_refi...-cylinder.html

Is there something else I should try to get this to work?

Thanks

If the arm slowly drops then you may have a blown seal somewhere in addition to trapped air. But first, it can take quite a bit of effort to get the trapped air out. You might try tapping the cylinder (with a large screwdriver or a hammer handle) as you pump, in order to encourage the air to migrate.

Most engine hoists have a large mechanical advantage and it will take pretty much no effort to pump up the beam by itself. When I'm raising my hoist to take up chain slack I usually don't even put the lever handle on, I just wobble the end on the pump directly by hand. It's faster and it keeps me from smashing the handle into something

[Woodsmith]

I would suggest bleeding and topping up the oil first as that is the easiest first step. Make sure the hydraulics are clean and the oil isn't taking any debris in with it.

If that doesn't make any difference then it is likely to need new seals.

In the meantime don't trust it to be safe in use as it could give up completely under load.

[Caps18]

Sadly, it looks like I might have to take the hydraulic jack apart to see what kind of seals it has. This was supposed to be a simple thing.

[Coley]

If you are borrowing it, don't take it apart, take it BACK!

[Caps18]

We don't use it anymore at work so they won't want to fix it, and that still leaves me with the same problem of not being able to remove the engine block that is in the way.

[Woodsmith]

If it belongs to work then I wouldn't try fixing it.




I would make them an offer for it at scrap value!
When I owned it then I would fix it!

[dragonsgate]

It could be as simple as the pressure release screw but if it has set for eight years with out ever being used it is likely the fluid has thickened and the check valve is not seating. If no water has gotten inside causing rust it may be as simple as disassembling cleaning and reassemble.

[onegreenev]

Go buy one.

[dragonsgate]

Originally Posted by onegreenev

Go buy one.

That’s no fun and it kind of takes the “Y” out of DIY.