Home Forums General Discussion Technical Questions Dover composite hydro overshoots first floor

Checked slowdown switches and working correctly there is only 2 magnetic switches for level up and level down when both switches pick I'm assuming that's how it knows it is floor level ? Any suggestion maybe cold oil ?

Is this the bottom landing? So you mean it's stopping high? Overshooting refers to running up, if this is the bottom landing the car will be stopping short not overshooting.

Interesting. I always use the word overshoot when a lift goes past level to its destination floor regardless of direction.

I'm not sure of this equipment but this is pretty standard for hydro's and how the stop works.

To the question, there will be a slow down signal, either via a magnet or the like switch which direct the hydro block to slow down(up slow valve) and level up to floor level. The 2 magnets at floor level would be lev up/down( essentially for floor level stop and loss of pressure relevel) and as soon as both magnets are seen it will stop. Cold oil could be an issue(remember cold oil is essentially thicker and prevents the valve from closing fast enough), but 2 quick runs will stop this (you can prove this by doing 2 runs). If this is an issue, a oil heater might be needed. However I would make sure that slow down signals are working right also.

Yes running past, if its the first landing then it does not run past. It either lowers below the landing or stop shorts, the pump is not running when you come into the bottom landing.

what im getting at if its only not floor level at the bottom landing its not gonna be a oil temp issue. It will be your floor level signal is out of adjustment(magnet, vane, switch, or what ever gives your floor levels). Now if it is shooting thru floors up the up direction oil temp can be a issue or the leveling adjustment in the valve.

Actually in our experience oil temp can have a dramatic effect on floor levels at the bottom floor(cold oil lift goes thru, hot oil lift stops short) and it became such an issue that we had to make the slow down ramp into the bottom floor longer than at other floors. This was what we had to do to stop breakdowns and to stop motor thermistor issues with the lift unable to level up properly. This might be the equipment but our experience. I would also caution on trying to attach lift motion to motor action and then name it over shoot or not. The simple fact is part of any lift is downward travel and in my opinion it either stop level high or low.

All the hydros on my route are TK/Dover I-2 or I-3 valves, I've never had any issue with a car mis-leveling in the down direction due to cold oil. Most likely those two mag switches are not adjusted correctly. When both switches are picked it tells the car its floor level. So try moving both switches down the distance you are stopping high. Also you might have a directional switch out of adjustment not allowing the car to fully come into the bottom landing. It may be a temp issue but first try adjusting the switches to see if your problem goes away. Mark the switches if it does not correct the issue to place them back where they went.

Does the job not have a print? Why are you guessing what tells the car its floor level? All that info should be on the print.

SB I would add my post regarding cold oil in the down direction is fixed after a few runs and generally only occurs first run/s of the day. When it's above the bottom floor the lift we just do a relevel up but when doing this at the terminal floor, if the lift goes too far it will trip the over travel limit and stop the lift until reset.

show me the reset on a relay logic dover

My input is generic only from my experience with multiple manufacturers of hydros. When I said reset, I meant you as a mechanic have to short of the over travel and send it up. We found on some models that if you lengthen the slow into floor into the bottom floor you can eliminate this issue. Sorry if their is confusion here.