Car lift problem

[leveled]

Yep. Had mine apart a few years ago.

Yes i am working alone too... I used a strap to hold it together, then I unbolted it and then pulled it down while removing the strap.

 

[leveled]

I took his posts to refer that the lift works fine if he starts it with it completely down or if he pushes the down lever as he starts it???

Both ways work. sorry for the confusion.

 

[ovrszd]

So we would be correct to assume the pump isn't locked up?

It's more likely that the motor won't start the pump if there's any kind of load on it?

 

[leveled]

The motor seems OK. Do not try to run the motor for more then 2 seconds if it will not start. There is no thermal shut off.
60Amps by 230Volts generates more than 10.000 Watts in heat in a blocked motor! ( 30.000 BTU per hr.)

If the motor runs OK when you hold the hydraulic lever in the "lower" position, than the pump should be OK. Check the hose to the cylinder for pinched or kinks, check steel cables, sheaves, and other mechanical. It looks to me that something is preventing the oil to flow to the cylinder or something prevents the cylinder from extending.

My mechanic thought the hose could be bad too. How would I test that? Thanks for the help everyone.

 

[ovrszd]

Hmmmm.... I'll have to think about that a bit.

 

[BertZegers]

My mechanic thought the hose could be bad too. How would I test that? Thanks for the help everyone.

Loosen the connection (do not take it apart) on the pump end of the hose en see if oil is pushed out when running the motor/pump. Then do the same at the cylinder end of the hose.

Be careful for the pressurized oil, you could wrap a transparent plastic bag around the coupling to prevent oil spraying on you.

 

[metalbender]

Just throwing something out here. Is there a weight limit switch in the system?

 

[aczlan]

No safety switch because it is a 4 post lift. In the magnet switch it is bypassed. The cables just max out.

Is there a mechanical lock to hold it up if something fails with the cables and or the hydraulics?
If so, can you lower the car to be held by the mechanical lock before starting the motor to raise it higher (as a workaround)?

Aaron Z

 

[BertZegers]

Loosen the connection (do not take it apart) on the pump end of the hose en see if oil is pushed out when running the motor/pump. Then do the same at the cylinder end of the hose.

Be careful for the pressurized oil, you could wrap a transparent plastic bag around the coupling to prevent oil spraying on you.

Another thought; there must be a "one way valve" close to the lever, I think, to prevent the platforms from lowering once you stop the motor/pump. If this valve is stuck in the closed position, than the oil can't leave the pump.
I would be behind one of the caps.

 

[mike48130]

Another thought; there must be a "one way valve" close to the lever, I think, to prevent the platforms from lowering once you stop the motor/pump. If this valve is stuck in the closed position, than the oil can't leave the pump.
I would be behind one of the caps.

This seems to make sense, there should be a check valve.