Followup on Braun Vangater II Problems

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swalker

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A little over 3 years ago I started a thread about issues I was having with my Braun Vangater II wheelchair lift and how we (mostly) resolved them. You can find that thread here: Braun Vangater II Stow Problem Resolved.

As a review, the lift would stall while doing the "stow" action (that is, tilting the lift to the vertical position). Once it stalled, the override controls, located on the lift's pedestal inside the van, needed to be used to work it through a cycle. Once that was done, operation returned to normal. The problem was mostly resolved by adjusting a potentiometer on the main board, reducing the sensitivity to the sensor that checked to see if there was too much load (such as a wheelchair and occupant) on the lift's platform.

When the problem recurred over the last couple of weeks, I suspected the new symptoms were being caused by some other factor. I reasoned that the sensor was detecting a load on the lift platform, but did not understand why it suddenly started behaving that way again. The potentiometer on the main board has not been adjusted since early 2016.

In fact, the problem was worse. The lift not only stalled when performing the "stow" action, it would stall between the "up" and "stow actions. It started intermittently, but as of yesterday seemed to be doing that about 90% of the time. This made the lift impractical to use by myself, because it meant that I would have to get out of my wheelchair, climb into the van, and then operate the override controls.

We dug into the problem and found that there were indeed a magnetic switch and some and contracts that were dirty. Cleaning those did not improve the performance. In fact, after we put the lift back together, the problem was significantly worse.

That was a key clue. It turns out there is a bolt that acts as a pivot of the vertical rod that drops down from the arm to the lift's platform. That bolt connects the vertical rod to the lift platform.

In reassembling the lift, we had over tightened that bolt, which meant there was too much resistance when the rod needed to pivot at that point. Loosening that bolt, essentially adjusting it the way it is meant to be adjusted, seems to have completely fixed the problem. We actually removed the bolt and cleaned up a lot of gunk that had built up over the years, then lubed it and installed it correctly.

The bolt and nut are items 41 and 42 in the "PARTS LIST VERTICAL ARM / HANDRAIL AND RELATED PARTS" diagram on page 19 of the "Braun Vangater II Wheelchair Lifts Installation/Service Manual for: Vangater II" document (the copy I have is dated June 2000).

My current suspicion is that this bolt has been over tightened ever since I bought the van used in 2015. I suspect it has been a substantial part of the cause of the balky lift behavior. I tested this fix extensively today and am quite hopeful this fix will dramatically improve the reliability of the lift.

A telltale sign that the previous owner had problems with the lift is that the cover that normally hides the override control panel was missing from the lift when we bought the van. I did not know enough about the Vangater II lift at the time to recognize that it was missing.

Steve
 

swalker

Very helpful member
Joined
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07/2014
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Here is another update. After working well for about 6 weeks, the lift starting being problematic with multiple failure modes. The symptoms were different than I had reported before, but ultimately resulted in the lift being unusable.

The symptoms were seemingly unrelated. Yet, I thought that there must be some single underlying cause. After extensive testing, disassembly, reassembly, head scratching, etc., we finally decided that it must have something to do with a sensor that had failed or was out of adjustment.

This lift has quite a few sensors. Some are magnetic switches and some are micro switches. After studying the service manual for a long time, I concluded that all the symptoms could be related to the "down" sensor (a micro switch) not being triggered when the lift was down.

We experimented with this (by removing the sensor and forcing the wires closed and concluded this was indeed the problem. We tested the sensor and found that it was working, so concluded the that it must have been out of adjustment.

After all that work, it turned out the only thing needed was to loosen two screws, adjust the sensor, and then tighten the screws. While the diagnostics took two weeks, the fix was less than 5 minutes!

The lift is now working reliably, which is a great relief.

Steve
 
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