Aloha, I will check the seals, as this could be it. The tilt seals were really bad when I replaced them, so maybe these seals too, although not leaking. (there never is any oil in the cylinder, so what is pushing up the ram? AIR? Francis

Sounds like your free lift cylinder seals are bad and hanging up.

Here is the serial D108N05297D Model E45Z-27 thanks Francis

Francis,

Remove the hose going to the center cylinder. Put the hos in a 5-gallon tied to something heavy so it does not come shooting out. Start the lift and pull handle to raise mast. Do you have oil coming out of hose? With the bleeder screw open you should have had oil coming out by now. Sound like there is no oil getting to cylinder. With serial number I can identify the mast and hydraulic arrangement.

Aloha, I will get serial in a bit. but I put a 2000# battery on the forks and can get it to come down. Once I take the battery weight off it will not go down. I had the top bleed screw off, (should I not see oil eventually coming out with the up and down? Francis

Francis,

The pump should not come on when lowering. Need to adjust the switches attached to the hydraulic handles. Post the serial number so I can verify what you have one the truck. My email is fishmechatcoxdotnet. Send me an email and will follow up.

1) There is no oil in the center cylinder and no oil comes out the top bleed bolt removed. (have not tried removing the main oil feed line at the bottom of the cylinder.
2) oil level is fine
3) will not lower with a load. (I put a 2000# forklift battery and it lifts to the 15' and when it comes to the center mast level, it stops.

(but should the oil pump be on when we lower?) thanks Francis

Francis,

That should be the carriage rollers. When lifted above the free lift stage, two always stick out of the mast. With the center cylinder hose removed from the cylinder, do you get any hydraulic oil when raising the mast? If not you have multiple problems. Verify oil fluid level in the tank. If the mast will lower with a load, suspect issues inside the free lift cylinder, (center).

Yes, it sure seems like something is catching, as when coming down and about to engage the center ram, there is a definite thud. Lift is very clean and newish condition, not a clunker and I cannot see anything contacting.

BUT *** there are 4 bearing wheels at the top of the center ram and 2 are sticking out above the rack. There are a total of 6 bearing wheels. I wish I could send a photo. thanks francis

Francis,

Check the mast rails to make sure nothing is catching when lowering. The cross supports from each rail should never touch the others.

Francis,

As stated earlier, each hydraulic handle has a switch attached to turn the pump on when the function is activated. Remove the cover that is at the lower portion of the control handles. You should see switches attached at the hydraulic handles. You will need to adjust the switch for the raise if the motor is coming on when you lower. If you remove the hose going to the center cylinder, does it lower? Was this cylinder rebuilt?

Thanks. there is a bleeder screw on the top, but the mast is already up. I have loosened it and activated the "up" and no oil comes out but the side cylinders start raising.
And (still I wonder why the pump motor runs when the down valve is pushed forward). thanks Francis

Francis,

It sounds like the sequence valve, some call it the shuttle valve has failed since you have no oil in the cylinder. First, look at the top of the free lift cylinder and see if you have a bleeder screw at the top. If so, loosen the screw and raise the mast until you see oil coming out of the screw. Tighten and test mast. If you do not have a bleeder screw, remove the hydraulic block, valve on the back of the mast and check all ports. Suspect you have a stuck valve inside. Good Luck.

Sounds as though you have a mechanical issue
Look inside the rails that the carriage rides in and see if anything is stuck in them I had a customer that made ceramic tile and once a month I had to chip clay out of the channel mind you not a big piece a very small piece that was pressed into where the roller would go and that was enough to do that it did same thing the piece was smaller than pinkie nail but it caused a lock up hard to believe but most mast have very little clearance between rail and carriage bearing also check your carriage bearings and be sure to be safe when working on the mast chain it and double chain it they can kill you !

Thanks John. tilt works fine and the side cylinders go up and down fine. As soon as it comes down to the center cylinder stage, there is a sharp thud. Almost as if there is something obstructing the tracks. We loosened the bottom hydraulic and took off the spring and star piece at the end of the spring. And still the piston will not come down and there was no oil in the cylinder even though the piston was all the way to the top. Francis