Hello
My name is Oliveira I live in Portugal and I have, together with my sons, a small company that deals and provides maintenance to forklifts. I've been an Electromecanic Engineer for the last 34 years but for the last 4 years I'm in the forklift business.
I provide maintenance mostly for a client who have around 80 Crown machines, and for the last 3 months I've been having problems and I'll put my question so that I can have some trully good technical advice for it:
Some of the new forklifts I have in this clients are showing up with the following problem, the forks descend very fast when I stop the machine with the forks up, and I think the problem is something to do with the hidraulic valves. I've exposed the problem with the manufacturer and the dealer in Portugal and they told me that the forks are legally allowed to descend at the rate of 10mm per minute (60cm/hour) and the problem is that I haven't purged (purge=take the air out from a closed sistem) the hidraulic sistem. Notice that from 25 new forklifts only 3 are making this.

IS THIS RULE TRUE (10mm per minute)???

IS THE DESCENDING OF THE FORKS CAUSED BY NOT PURGE THE HIDRAULICS???

I really hope that I get your attention and all the information you can provide me will be very helpfull and I will provide everything I know to help you in the future with whatever you might need.

Thanks,
Joaquim Oliveira