Hi , I am having issues with a dover twin post telescopic ( 3 floor) going out of synch. I am not too familiar wither dover stuff so bear with me if its something obvious!.. as you are looking from the landing when it gets to the ground floor the left piston stops sooner than the right causing the car to rack and make a pretty horrible thump on take off. if I lower onto buffers it re-synchs. it will sometimes then be ok for two weeks sometimes goes within the hour . I have tried adding a quart of caterpillar additive in case the packing was tight, there are no visible leaks , I have bled the air best I can from the bleed screws at the top of the jacks, tried resynching it by both lowering AND running it up onto the stop ring . The cab isn't 'binding ' in the hoistway as far as I can see and I softend up the take off in down direction ( was a bit harsh ) and the transition/stopping. this is the only dover I have on my route and as yet do not have a tool ( thanks to my salesman for taking on a job without even asking if I had the tools to work on it ! ) but I did manage to lay my hands on one yesterday and checked the autosynch function was set as in the booklet with the tool (if I recall there are 3 settings in timers and all were set as factory and one setting in CLC adj to enable the function which was set to 2 for twin post ).
I presume that there must be internal seals at the bottom of the smaller diameter piston , I look after some cemco jobs that when they go causes similar issues . Are they likely to be the cause ? I don't want to start trying to figure a way to pull pistons out if its something obvious im missing
any help or advice will be greatly appreciated.
