2 Post Lift: Unequal up and down?

[70runner]

7K two post lift, about 7yrs old. For last couple years have noticed an issue with unequal lifting and lowering. Left side has 1-2sec delay when powered. Left side also lowers at faster rate. I can compensate by using the safety locks during lift and lower, but need to get this fixed as it seems to be getting worse.

The lift worked fine for 4-5yrs. Pressure lines are identical lengths. I've done the bleeding procedure several times but has no effect on issue. Candidates would seem to be the flow divider or left side cylinder. Suggestions?

 

[buckshot00]

have you run the lift all the up to the top (with or w/o a car on)? That used to 'equal' the arms at my buddies shop

 

[DaveInHouston]

I assume your lift has equalization cables? The synchronization of the lift arms is dependent upon a proper adjustment of the equalization cables and really has nothing to do with the cylinders. The equalization cables (one for each side) should have an almost equal amount of torque or pressure. They do get out of adjustment.
And bty they can be a pain to get a wrench on the lower cable nut section. I fabricated a wrench to reach down, hold the cable, while I tightened the top nut with a socket and ratchet.

 

[70runner]

have you run the lift all the up to the top (with or w/o a car on)? That used to 'equal' the arms at my buddies shop

Yes, no change.

I assume your lift has equalization cables? The synchronization of the lift arms is dependent upon a proper adjustment of the equalization cables and really has nothing to do with the cylinders. The equalization cables (one for each side) should have an almost equal amount of torque or pressure. They do get out of adjustment.

No equalization cables.

I switched the pressure lines at the power unit and the left side was still delayed. Suggests to me a problem with the cylinder. Cylinder has no brand or model# on it. I've contacted the dealer and they haven't responded yet.

 

[DaveInHouston]

No help from me then. I’ll be interested to hear what the solution is. Good luck.

 

[Jking24]

What brand and model lift is this? all lifts have some sort of equalizing system. If operated independently the only thing controlling witch arm moves first and how far is friction

 

[3rdgendslmech]

This is just a hunch, but you said there are no cables. Could it be possible that the hydraulic lines have to be equal length? Oil takes the path of least resistance, maybe one of the carriages needs sprayed down with some lube?
Another option would be to tie in a flow control valve into the faster moving cylinder to slow it down some.

 

[575cat]

No equalization that would be a sight .

 

[DaveInHouston]

Any solution?

 

[Robert Haas]

Do they really make a lift that has no equalizing mechanical attachment?

What the hell would happen if you had a cylinder failure?

I would not put a tricycle up on such a stupid design.

 

[firebirdparts]

Well, those quickjacks and maxjacks are like that. Hydraulically synchronized. It's not too good. Personally I'm glad I never learned how to troubleshoot 'em.

An air bubble would definitely cause your problem. Cylinder through-leakage would be very obvious. If you had that problem you'd know. I don't know what can go wrong with the divider.

Incidentally, I sat next to Don Cray on a plane one time, and he patented that. he had invented a portable lift of a style that never caught on, really. He also patented a low ceiling lift sort of like some of you guys have.

 

[70runner]

To close this out... Ordered and installed a seal kit on the cylinder. Had virtually no effect on the problems. Left side lift continued to delay, about 2sec, compared to right and also came down quicker than right. Company tech support was not very helpful, their go-to solution was adding a flow control valve. They generally relayed my questions to the "factory reps" in China, so it was usually 2-3 days before any response.

As noted, this lift is hydraulically equalized, no cables. Lesson learned, don't buy another one of these. I've avoided mentioning the model as to not create a bashing thread as there are others on this forum who are using the same lift. I'll mention it now, Triumph C7000 purchased from National Auto Tools in Texas, if only to alert other C7000 owners that tech help, if needed, may be less than effective.

The problems with the lift continued to worsen so I replaced it with an Atlas BP8000.

 

[Jwco5.3]

How is the Atlas treating you? I’m shopping for a lift for my 9 foot ceiling and can’t seem to talk myself into buy a lift that use a flow diverted to equalize the sides. That leaves me with the Atlas BP8000, the Bendpak GP7-LCS, or a scissor lift. Does the floor plate get in the way all that much?