Hyster fork lift

[37chief]

I have an old Hyster fork lift. Probably 50 years old, maybe more? So far It has lifted everything I needed it to lift. I am scrapping a couple old crawler tractors. My Question is: If pick up something too heavy, will there be a bypass valve in the hydraulic system so I don't blow out a seal, or worse. I did notice one time with the mast all the way up, it blows oil out. Mybe this was designed to do this, or maybe a bad seal? One thing it sure is handy, to have around. Stan

 

[used red MN]

Every hydraulic system has a pressure relief valve. Without it things break, remember back in school science you learned liquids do not compress. Does it have an external low pressure hose that runs up to the top of the cylinder? If so this is a seal “leak by” return. The main mast is a one way cylinder. If the seal bypasses it would leak externally and make a mess. To curtail that mess that return hose is added. When you have the mast cylinder all the way up there may be no volume area to act as a reservoir to hold the bypassed fluid and let it slowly return to the main tank so it leaked out externally. Actually just my best guess. However, the pressure relief is for certain.

 

[stevieb49829]

I have an old Hyster fork lift. Probably 50 years old, maybe more? So far It has lifted everything I needed it to lift. I am scrapping a couple old crawler tractors. My Question is: If pick up something too heavy, will there be a bypass valve in the hydraulic system so I don't blow out a seal, or worse. I did notice one time with the mast all the way up, it blows oil out. Mybe this was designed to do this, or maybe a bad seal? One thing it sure is handy, to have around. Stan

I've never seen one that had anything go wrong trying to lift too heavy. They just won't lift it. The pressure relief valve, if set appropriately, will open, thus, no more lift, like Used red stated. Or you tip the forklift over!! I've hooked underneath 4 units of 3/4 particle board, and the forklift just turned around and stared at me with that "you kidding me?" look. steve

 

[Bob Bancroft]

I have an old Hyster fork lift. Probably 50 years old, maybe more? So far It has lifted everything I needed it to lift. I am scrapping a couple old crawler tractors. My Question is: If pick up something too heavy, will there be a bypass valve in the hydraulic system so I don't blow out a seal, or worse. I did notice one time with the mast all the way up, it blows oil out. Mybe this was designed to do this, or maybe a bad seal? One thing it sure is handy, to have around. Stan

I have a forklift old enough it has cups instead of o rings or seals. As already explained, it has the bypass, or return hose going to the top of the one way cylinder. Even so, it would push the seal/wiper out along with some oil. I cleaned and re installed the seal with loctite, and it stays in place now. I find that leaving either of my forklifts with a raised load long term guarantees a leak somewhere, so I just don't do it.

 

[5570 standard]

I have a forklift old enough it has cups instead of o rings or seals. As already explained, it has the bypass, or return hose going to the top of the one way cylinder. Even so, it would push the seal/wiper out along with some oil. I cleaned and re installed the seal with loctite, and it stays in place now. I find that leaving either of my forklifts with a raised load long term guarantees a leak somewhere, so I just don't do it.

Counterweieght is your safety valve. Overload will raise the back end.

 

[Pete-IN]

I have an old Hyster fork lift. Probably 50 years old, maybe more? So far It has lifted everything I needed it to lift. I am scrapping a couple old crawler tractors. My Question is: If pick up something too heavy, will there be a bypass valve in the hydraulic system so I don't blow out a seal, or worse. I did notice one time with the mast all the way up, it blows oil out. Mybe this was designed to do this, or maybe a bad seal? One thing it sure is handy, to have around. Stan

I drove electric forklifts in a factory for 42 years. Various brands. When overloaded, the rear end comes off the ground.

 

[JD Dave]

What is the rated lifting capacity of the Hyster? You shouldn't have a problem but crawlers are heavy beasts and you don't want to bend the forks. Just take it easy.