This is only applicable to dump trailers that hydraulically raise and lower the bed. You cannot do this if it is gravity down/pump up.
The Surplus Center recently put their hydraulic tongue jacks on sale for $60.00 which sucked me in to finally doing something I been wanting to do for awhile now. It was a pretty easy project and I thought I'd run down what I did to help out anyone else who might be considering the same project.
The only real issue with this project was that the bolt holes on the new jack do not line up with the existing holes and the new jack's base is quite a bit larger than the standard trailer tongue jack. I used a piece of 1/4 inch plate to make a new plate for the jack to fit into. You will need to cut a hole for the jack with a hole saw (2 1/2" as I recall) and then cut a small notch at the back with an angle grinder to accomodate the hydraulic lines. After marking and drilling the new mounting holes I welded the new plate to the trailer's frame. If you are not a welder you could easily bolt it to the frame instead.
You are going to use the existing hydraulic pump to operate the jack and the dump unit by inserting a hydraulic selector valve into the circuit. I found the selector valve at Northern for $114.00 less the readily available $20.00 coupon. It does not come with a schematic, but the schematic is readily available on-line.
I mounted the valve to the front inside of the tongue tool box, but the location cn easily be changed to any place you want by changing the length of the hoses you buy.
In my case the pump connections were JIC6 connectors, but you will need to determine what connectors you have from the pump to the existing dump cylinder lines.
I chose to use 3/8" lines to match the existing lines.
Once the valve location is set and the valve is mounted you will need to remove the hydraulic lines from the pump that go to the dump cylinder while keeping track of which line raises or lowers the dump. Follow the schematic for the valve and run the existing lines to the appropriate valve ports using whatever adapters are needed. You will then need to run new lines from the pump to the appropriate valve ports. Finally you will need to drill holes in your tool box to allow the hydraulic lines from the jack to reach the valve. I chose to drill the lines in the front of the box and I used a rubber grommet to keep the lines from chafing. I got the grommets from Amazon.
One issue I had was figuring out what fittings and lines I needed so here is what I ordered:
Since I was ordering from the Surplus Center I ordered straight and 90 degree fittings to be sure I had what I needed. The extra cost was minimal compared to getting them locally. I ended up using a mix of both and depending on where you locate the selector valve you will need to change the length of the hoses that run from the jack to the valve. 36" was plenty if you run them through the box front, but if you want to route them around the side you will need 60" or more.
All in it ended up costing me right around $300.00 and I could have saved some cost if I had ordered the fittings and hoses with the jack. Was it worth it? It certainly makes hooking up the trailer much easier and since I seemed to be replacing the hand crank jack every 3 or 4 years I think it will probably be a cost saver over the years.
The Surplus Center recently put their hydraulic tongue jacks on sale for $60.00 which sucked me in to finally doing something I been wanting to do for awhile now. It was a pretty easy project and I thought I'd run down what I did to help out anyone else who might be considering the same project.
The only real issue with this project was that the bolt holes on the new jack do not line up with the existing holes and the new jack's base is quite a bit larger than the standard trailer tongue jack. I used a piece of 1/4 inch plate to make a new plate for the jack to fit into. You will need to cut a hole for the jack with a hole saw (2 1/2" as I recall) and then cut a small notch at the back with an angle grinder to accomodate the hydraulic lines. After marking and drilling the new mounting holes I welded the new plate to the trailer's frame. If you are not a welder you could easily bolt it to the frame instead.
You are going to use the existing hydraulic pump to operate the jack and the dump unit by inserting a hydraulic selector valve into the circuit. I found the selector valve at Northern for $114.00 less the readily available $20.00 coupon. It does not come with a schematic, but the schematic is readily available on-line.
I mounted the valve to the front inside of the tongue tool box, but the location cn easily be changed to any place you want by changing the length of the hoses you buy.
In my case the pump connections were JIC6 connectors, but you will need to determine what connectors you have from the pump to the existing dump cylinder lines.
I chose to use 3/8" lines to match the existing lines.
Once the valve location is set and the valve is mounted you will need to remove the hydraulic lines from the pump that go to the dump cylinder while keeping track of which line raises or lowers the dump. Follow the schematic for the valve and run the existing lines to the appropriate valve ports using whatever adapters are needed. You will then need to run new lines from the pump to the appropriate valve ports. Finally you will need to drill holes in your tool box to allow the hydraulic lines from the jack to reach the valve. I chose to drill the lines in the front of the box and I used a rubber grommet to keep the lines from chafing. I got the grommets from Amazon.
One issue I had was figuring out what fittings and lines I needed so here is what I ordered:
| Qty: | Item #: | Description: | Ext Price: |
| 2 2 2 2 4 4 2 2 1 | 9-6901-6-6 903-3818 918-3236 9-6900-6-6 9-1501-8-6 9-1404-8-6 9-2404-6-8 9-2501-6-8 | SAE 6M x 3/8 NPTF 90 SWIVEL (for the jack fittings) 3/8" X 18" 3/8 NPTM X 3/8 NPTM 3000 PSI HYD HOSE (from pump to valve) 3/8" X 36" 3/8 NPTM X 3/8 NPTM 4800 PSI HYD HOSE (from jack to valve) SAE 6M x 3/8 NPTF SWIVEL (for the jack fittings) 1/2 NPTM x 3/8 NPTF 90 SWIVEL (for the valve fittings) 1/2 NPTM x 3/8 NPTF SWIVEL (for the valve fittings) JIC 6M x 1/2 NPTM CONNECTOR (pump hose to valve) JIC 6M x 1/2 NPTM 90 ELBOW (pump hose to valve) Hydraulic Toungue Jack |
Since I was ordering from the Surplus Center I ordered straight and 90 degree fittings to be sure I had what I needed. The extra cost was minimal compared to getting them locally. I ended up using a mix of both and depending on where you locate the selector valve you will need to change the length of the hoses that run from the jack to the valve. 36" was plenty if you run them through the box front, but if you want to route them around the side you will need 60" or more.
All in it ended up costing me right around $300.00 and I could have saved some cost if I had ordered the fittings and hoses with the jack. Was it worth it? It certainly makes hooking up the trailer much easier and since I seemed to be replacing the hand crank jack every 3 or 4 years I think it will probably be a cost saver over the years.
