Floor Jack Problem

[u118224]

I have a HF China 3 ton floor jack. It will only lift to 1/2 - 2/3rds of its range and then stops. Otherwise, it lifts fine.This is my backup jack but I do need it from time to time. The unit is full of oil, does not leak oil and is not air locked. I read Hiball's rebuild thread but I can't see the pictures at my work computer. Any thoughts?

 

[signcrafter]

PM hiball and he can help you out and sell you the parts needed to fix it.

 

[Outlawmws]

I'd start with a drain/flush and refill. that does not sound like you actually have it properly full, or it sounds like you have air in the pump somewhere, (Possibly moisture related? Hyd fluid will absorb moisture...)

 

[u118224]

Changing the oil occurred to me after I posted. I'll try that first.

 

[Hiball]

I have a HF China 3 ton floor jack. It will only lift to 1/2 - 2/3rds of its range and then stops. Otherwise, it lifts fine.This is my backup jack but I do need it from time to time. The unit is fill of oil, does not leak oil and is not air locked. I read Hiball's rebuild thread but I can't see the pictures at my work computer. Any thoughts?

I doubt changing the Oil will do any good... Is this jack your typical Yasui designed jack or is it a Quick Lift Jack? Does your jack stall out at 1/2 - 2/3rds of its Range only under load or does it do it also without Load?

 

[u118224]

I doubt changing the Oil will do any good... Is this jack your typical Yasui designed jack or is it a Quick Lift Jack? Does your jack stall out at 1/2 - 2/3rds of its Range only under load or does it do it also without Load?

It's NOT a quick lift. It stops at 1/2 - 2/3rds with and without a load. With no load, I can manually pull the saddle to max but it just falls back to 2/3rds or so. I'm guessing the jack is 10 - 15 years old, I bought it new.

 

[Hiball]

It's NOT a quick lift. It stops at 1/2 - 2/3rds with and without a load. With no load, I can manually pull the saddle to max but it just falls back to 2/3rds or so. I'm guessing the jack is 10 - 15 years old, I bought it new.

And your sure it has enough oil in it? With the Lift Arm completely Lowered where is the Oil level? Have you tried running the Jack through a Full cycle with the Fill Plug removed?

 

[u118224]

And your sure it has enough oil in it? With the Lift Arm completely Lowered where is the Oil level? Have you tried running the Jack through a Full cycle with the Fill Plug removed?

With the jack lowered I pulled the fill plug and the oil is full. I pumped the handle with the fill plug removed several times. I also pumped the handle with the valve open and the fill plug tight. Maybe something is cracked and is letting in air?

 

[Hiball]

With the jack lowered I pulled the fill plug and the oil is full. I pumped the handle with the fill plug removed several times. I also pumped the handle with the valve open and the fill plug tight. Maybe something is cracked and is letting in air?

When you check the Oil, Are you looking at the Reservoir or are you pulling one of the Valve plugs? I only ask because i cant tell you how many people have torn into the Valves thinking this is the Fill hole when its actually on the Reservoir/Block <-- Sometimes. If you are in fact checking the Reservoir, And its Nut Full its would best to drain some of that oil out, If you peer through the hole you will see the Cylinder inside and the oil level should rest just above it or aprox 5/16" below the hole. Hydraulic Jacks need to breathe and if you fill the Reservoir completely full, Then bottle it up with the Plug/bolt it will draw a heavy Vacuum.

 

[u118224]

I'll check it out and report. I have the HF manual, it shows where the oil check is.