Dump trailer hydraulics

[1gr8bldr]

Here is what is on the hydraulic ram. Cross Manufacturing Lewis KS 2500 PSI working pressure 3.5 bore 30 stroke 1710 max psi at base port. So assuming it is fine, this is what needs to be mated with pump when designing a new better system

 

[1gr8bldr]

Do I need something like this? I really need this for next weeks job, not to mention that it is loaded now. I had rather bite the bullet, fix it the quickest way possible.
Concentric 12 Volt DC Power Unit, No Valving, Model# 1261009 | Hydraulic Power Units| Northern Tool + Equipment

 

[1gr8bldr]

Maybe this one, LOL, somebody tell me what I need and I'll try to understand later
Concentric 12 Volt DC Power Unit, Solenoid Operation, Single-Acting, Model# 1261014 | Hydraulic Power Units| Northern Tool + Equipment

 

[1gr8bldr]

de;ete

 

[1gr8bldr]

Haldex is now concentric
haldex hydraulic power unit from Northern Tool + Equipment

 

[1gr8bldr]

Can someone explain single acting? Maybe use my skidsteer as an example. The main lift pushes up and down. Is that the opposite of single acting?

 

[George2615]

If it was mine I'd replace the pump unit. They come with wiring diagrams and a reserve tank. For an example to look at go to Graingers.com and type haldex barnes in the search line. The standard units such as Graingers part# 4NE83 come with a 2 qt. reserve tank. Some come with a 3 qt. tank. Models to look at would be the 4NE18, 4NE15, 4NE16, 4NE17, 46C519, 46C520. 2 1/2 gallon tanks #4NE25 or 4NE27 are available. Check the ones that come with the remote switch as they all don't come with a switch and wiring. Maybe you could get the lower priced unit if you can re use your remote switch. If you decide to buy from another Haldex dealer Graingers lists the manufacturer model number for each pump, just write the one down you need.
If you have a hydraulics shop in your area you could drop your unit off for repairs but you may not have it back by next week.

 

[George2615]

Can someone explain single acting? Maybe use my skidsteer as an example. The main lift pushes up and down. Is that the opposite of single acting?

An example of single acting would be the second pump you saw at Northern with the remote wiring switch. It would have one pressure hose going to the bottom port of your cylinder. To raise the dump you press your button, the motor pumps fluid into the cylinder raising the bed. When you press the down button the motor does not run but the switch powers a solenoid valve which releases the pressure and lets it run back into the tank.
A double acting pump will have two hoses. One will go to the bottom and one to the top port on the cylinder. On a double acting pump the motor will run to power up the bed and run to power down the bed by applying fluid to the proper hose.
You already have a double acting cylinder which has 2 ports but it can be used as a single acting by feeding the lower port only. I have been using my DA cylinder this way for the past 6 years. I just have a plug in the top port.

When buying a new pump make sure you get one rated at 2500 PSI since that is your cylinder max pressure. Some of the pumps I referenced were 3000 PSI.

 

[jenkinsph]

Really all you need is more volume and a vent for the system. You might be better off to use a long turn 90 degree piece of tubing that will stick in the tank closer to the bottom of the reservoir that the cylinder low pressure hose attaches to. This can be installed with a new hole to match the tubing size in the top of the tank. Then put the proper vented cap back in place on the tank as it originally was. Seal the hole around the tubing you add with a good silicone sealant. You will need to make sure the top of the ram is full of fluid which might be a pita but that should fix you up.

Once you have the air out of the top of the cylinder and its hose, the oil should not have air introduced in the system. The reservoir at this point only needs the extra capacity to make up for the volume of fluid that the cylinder rod displaces with a little air space. When you let the box down and the cylinder retracts it allows the fluid to flow back into the reservoir, at the same time the top of the cylinder is sucking the fluid out of the reservoir and into the cylinder. Raising the cylinder the reverse happens.

 

[George2615]

Really all you need is more volume and a vent for the system. You might be better off to use a long turn 90 degree piece of tubing that will stick in the tank closer to the bottom of the reservoir that the cylinder low pressure hose attaches to. This can be installed with a new hole to match the tubing size in the top of the tank. Then put the proper vented cap back in place on the tank as it originally was. Seal the hole around the tubing you add with a good silicone sealant. You will need to make sure the top of the ram is full of fluid which might be a pita but that should fix you up.

Once you have the air out of the top of the cylinder and its hose, the oil should not have air introduced in the system. The reservoir at this point only needs the extra capacity to make up for the volume of fluid that the cylinder rod displaces with a little air space. When you let the box down and the cylinder retracts it allows the fluid to flow back into the reservoir, at the same time the top of the cylinder is sucking the fluid out of the reservoir and into the cylinder. Raising the cylinder the reverse happens.

In post 40 he said he lost all the fluid. Came out between the tank and pump. I think He either needs to rebuild or buy a new pump.