Datsun/Nissan forks wont go down to floor.

Like the title says, on my old Datsun/Nissan, the forks will go up just fine, but when going down, thay stop about 9 or 10 inches from the floor.

Anybody run into this before? I think its hydraulic, but don't know where.

I would make sure the problem wasn't mechanical first. There are mast rollers and guide rollers and other stuff that, on a old forklift would be more suspect than a hydraulic malfunction. It's a single acting cylinder so it will rely on the weight of the carriage to bring it down. If it comes down at all then it should come down all the way unless something mechanical is stopping it.

The ram probably has a vent on the dead side so make sure that's not plugged with earwigs or killer bees.

Stuart

Did they just all of a sudden stop going down? Maybe something is blocking the mast, raise it all the way and look at it.
I have a datsun lift with a 3 stage mast, goes up about 15'. One central freelift cyl and two outboard ones that take over when freelift is done. Cant remember now but one of them has a check valve at the bottom, that could also be something to look at. IIRC mine has bleeders at the top of one or two of the cyl bodies, there is a little allen head pipe plug in them.

Does the cilinder go down and the chain(s) slacken when holding the valve ??
If so it is mecanicly If not hydraulicly

Peter

9"-10" I think is about where I sometimes see a second stage start to move when going up.

As stated above, look for a hydraulic check valve or sequencer, also I recall one forklift hade a large mechanical latch (very rough built, made with burnouts of 1/2" plate)
and it's job was to hold the section down until something went past it, to trip it off. could be it's stuck.

Clearly they went to the floor and slack lift chains in the past, or within 1/4” right? Do you still get slack chains after they stop lowering? Not much surprises me anymore but if it’s hydraulic I will be surprised once more.

IME the 1st, freelift stage typically gets the forks up 3-4’ or so but that seems incidental, I would eliminate all mechanical hang-ups in the 1st mast section then move on to the 2nd &3rd stage before opening up any hydraulics.
But it’s your machine.

Thanks to everyone for a lot of good tips. To answer Peter about slack in the hoist chains, no, I have not noticed any obvious slack. When it decides to stop, it is a solid stop. Don't hear anything, like it may be mechanical, but you never know. One thing that is unusual about it is the fact that it will eventually, after several days, maybe a week, it does get to the floor. This makes me wonder if it could be hydraulic. I'm gonna be busy for a few days, but when I do learn what I'm up against, I will come back and bring you up to date.

Thanks, again
JH

James H Clark said:

Thanks to everyone for a lot of good tips. To answer Peter about slack in the hoist chains, no, I have not noticed any obvious slack. When it decides to stop, it is a solid stop. Don't hear anything, like it may be mechanical, but you never know. One thing that is unusual about it is the fact that it will eventually, after several days, maybe a week, it does get to the floor. This makes me wonder if it could be hydraulic. I'm gonna be busy for a few days, but when I do learn what I'm up against, I will come back and bring you up to date.

Thanks, again
JH

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Does it stop in the exact spot every time? My first thought is that the cylinder tube may have been bashed about a foot off the floor. That would cause the piston at the bottom of the ram to bind, but if that is the case, it wouldn't lower farther without a lot of weight on the forks.
When you say that it eventually gets to the floor, do you mean that you come back to the machine and they are on the floor with no manipulation on your part, or you push the lever and they drop, or do you tie off the lever so the valve stays open and it eventually lowers?
If the height that it stops is inconsistent, and it lowers when you push the lever after a few days, it's most likely a problem in the freelift cylinder itself, a bad load lowering valve or velocity fuse.

Ted

I suspect this to be an older lift, as many of us can tell you is that we age the floor grts farther and farther away until one day you find that you can no longer reach it. The exception is of course when you fall onto said floor and are unable to escape its grip.