Installing wet line on volvo 670

What are you going to do with the wet line?

The hardest part (and the only one I've outsourced to a shop) is mounting the PTO. Not that I don't think I can do it, I just can't afford to screw it up.

Hydraulic pump bolts up to the PTO. You'll have to fabricate a bracket...easiest way is to take 2 pieces of heavy gauge flat steel and drill a hole in each end. Bolt one to the transmission, the other to the pump. Bend, twist, and do whatever else you have to do to them to get them to match up perfectly...then clamp them together, remove them, and weld 'em together. Then bolt it back in and tighten everything up.

You'll need a hydraulic tank. They come in a variety of ways...saddle mount, or frame mount (on the catwalk) are the two most common. I had my right side fuel tank split...they cut the end off, weld in a baffle where I needed it, added a couple bungs, a vented cap, and welded the end back on.

For a simple end dump, you run a suction line (steel wire reinforced so it doesn't collapse) from the tank to the pump, then a high pressure line from the pump to the coupler for the trailer. When you lower the trailer, the oil flows back the way it came.

You can also add a return line from a second trailer coupler back to the tank if you will need a return line....that would be for side dumps, low boys, etc...anything where the hydraulic power comes from the truck, but the controls are located on the trailer.

If you want to get a little more complex, you can add a return line from the pump back to the tank, which on some pumps is as simple as removing a plug from the pump and running a line from there back to the tank. This lets the pump circulate oil back to the tank instead of internally within the pump when in the "hold" position...helps keep the pump from overheating.

On mine, I ran the return line from the pump up to a T below the return coupler from the trailer, then through a filter on the way back to the tank.

Then there are other wet kits where both the power AND the controls are in the truck...and those will require more valves and such on the truck in order to control direction and rate of hydraulic oil flow.

There's a bunch of different ways you can go with a wet kit on a truck...just gotta figure out what you need it for and go from there.

Once you have the major components, you'll need a way to control them. That's typically done with air power. You'll need an on/off switch for the PTO. For an end dump, you'll also need a 2-way switch that normally stays in the center position. One direction you should have to hold the switch in order for it to stay (set that to raise the bed), and the other way the switch should stay put when you flip the switch (lower). You can also buy controllers that do all of that, with the added benefit that they will kick the PTO off when you move the control switch to lower the bed. If you are doing other things with your wet kit, the controls you select will have to be able to make the wet kit do what you want it to do.

Your truck dealer or any tractor trailer parts store ought to be able to help you out when it comes to selecting individual components or even putting it all together and installing it for you.



When it comes to making hydraulic lines, that is the ONLY part that requires any "special" tools. I used old pieces of garden hose and routed them where I wanted them...templates...so that I could take them in to the local NAPA (or any other place that will make hydraulic hoses) and have the lines made. I also put male fittings on all of the components, and have female swivels on both ends of all of my hoses. If you put the male end on the hose to thread into the component, you have to turn the whole danged line to thread it in and tighten it...and it's tough to do without getting a bunch of crap in the other end of the hose.

 

You'd actually be better off having a hydraulic tank on the truck...the lines running to the trailer aren't strong enough and will collapse under the suction of the pump....leading to burned up pumps.

All of your controls are on the trailer...so your only concerns are:

1) a PTO and pump capable of continuous operation

2) find out what pressure the trailer needs to operate and set the pump at that pressure



What you'll need is a simple "on/off" switch for the PTO. When the PTO is engaged, it is pumping oil through the system.


You'll route:

1) a suction line from the tank to the pump.

2) a pressure line from the pump to a coupler which will hook into the trailer hydraulics

3) a return line from a second coupler back to your tank



When it comes to the trailer, that's where the tricky part comes in. You'll have to run a pressure line from the nose of the trailer back to wherever the line from the electric motor/pump ties into the hydraulic system. Disconnect that line, and connect the new pressure line in it's place. Then, do the same with the return line, disconnecting the line back to the trailer's tank and replacing it with the return line to the front of the trailer. You could probably find a coupler to hook the end of the line from the electric motor/pump to the return line just to keep contaminants out of the trailer system. Best way to do all of this would probably be with quick connects or with twist connect fittings (like on dump trucks)...makes switching things around a little quicker and you won't need tools beyond the initial set-up.

 

the pump and valve is all one unit ....no bracket needed ....the pump is is easy to install just drain your trans and remove the plate on the trans and the pump will bolt right up you just need to make sure there is a slight amount of play when you turn the output shaft of the pump back and forth if not the pump comes with shims to put on top of the pump untill you get the play needed.the pump will come as a kit with the pto switch and valve and you just have to run a couple of 1/4 inch airlines for that..... as far as the tank what i did and most do is take off the right side fuel tank and have a welder split it ....cut it so you'll have about 40 gallons of hydraulic oil re-weld back together with a plate between the two and you can buy the bungs (threaded inserts) for the fill and and outlet..... you will have to have a hydraulic pressure hose made up to go to the trailer.
now if you are doing a walking floor setup you will need a higher press pump (2600 psi vs 2200psi for dump trailer) and a return line fitting on the tank with a pressure return line to the tank.....

if you do it yourself it can easily be done for less than $1700 .... if you pay to have it done expect $3000-$4000 bucks

 

You DO need a bracket for the pump. The PTO and the pump are two separate things. The PTO bolts to the transmission, and the hydraulic pump bolts to the PTO. You NEED a bracket from the hydraulic pump to the transmission, because that is a LOT of weight to be hanging off the PTO. You WILL crack the PTO housing (if you are lucky) or the transmission case (if you are not) if you do not support that weight with some sort of bracket.



The blue thing is the PTO. The red thing is the hydraulic pump. The plain metal piece between the pump and the gold color grade 8 bolt on the transmission is the bracket he needs to make. The silver thing on the front of the pump with the air lines running to it is the air cylinder that controls the pump (raise/lower). The air line going in to the top of the PTO is from the dash switch that controls the on/off for the PTO.

 

mine was different than that much smaller one unit pump and pto... no bracket... which i installed i dont have that truck any more i think the one on my current truck is similar to yours i think but it was on there when i bought the truck and really never payed much attention to it as i havent done any bucket work in 5 years since i bought this truck

 

i plumed my steering pump up to my lowboy works great in the winter i mounted the oil reseivor on top of my motor the heat of the motor keeps the oil warm. never had a problem with collasped lines.

 

Thought i'd add my 2 cents.
I would be tempted to go to your nearest hydraulics place(any place that does a lot of heavy equipment hydraulics, dump body installations, hyd. cyl. repair etc.) and tell them exactly what your application is, and the pressures and amount of flow you will be dealing with in this system.
They will ask you what make and model your transmission is and at what engine speed you wish to operate the system at.This allows them to select the proper gearing for the PTO and what size pump you will need in order to match them to each other.
They should also ask if you want a bottom or a side mount PTO. I prefer the bottom mount because it usually offers more clearance, but be sure to look under there first and see which one would fit best on your truck.
In your circumstance where you will just be feeding an open center valve body, getting everything matched perfectly isn't super critical, but it never hurts to try.
I am definately not a guru on the subject,but I have installed a few, and getting the right parts to start with always seems to help my projects go smoother.
Installation is not difficult but can be time consuming in order to do a good job. No special tools are required except maybe a dial indicator to set the lash on your PTO.
I think the hardest part is getting the #### hose lengths right!!
I like the idea of using old garden hose for figuring lengths!! I'm gonna use that one.
Thanks.
Anyway, hope this helps, and good luck.
Floyd

 

I drove a logging truck for 15 years and the place I worked at didnt use hydraulic oil for his log loaders, he used Automatic Transmission Fluid. Oh sure if a hose blew it looked like a crime scene (the red color) but if it was below 0 you didnt have to wait for the oil to warm up.