Everything you Need to know about Dump Pumps

I’m Dave from Parts for Trucks. So we’re going to cover today just how we went from the original C101 dual-shaft pump to the more modular design of the Permco MVP.

So when I first started in this business, the only pump really in existence at the time was the old dual shaft pump. So this is just your standard dump pump that you see out there in the market today. But most of those were run by driveshaft. So today’s you can see that they’re now splined  and coupled directly to the power take off. But in its day, you would choose whether you needed a right hand rotation or a left hand rotation unit. And we would connect your drive shaft to here. And other than the drive shaft, the pump is pretty much exactly the same. So the migration has come from why complicate things with the drive shaft? It’s another piece to break down. It’s another piece to service. If we can remove that, then we’re going to save you some money and hopefully improve on some efficiencies.

That brings us to the granddaddy pump. This is the Parker c102. It’s the as far as I know, it’s the original splined dump pump.
And it’s the one that has the most recognized trade name being the C102. There are some variations of it, but if you walk into any parts counter and say, I’m looking for a C102, this is what you’re going to see. So directly coupled to the power take off, unlike it’s the C101, which is the driveshaft version, the pump doesn’t change much over the years. In fact, it was probably unchanged for, I would say 25 or 30 years before something else came along and affected the industry. With these, I’m going to have to turn this around here and show you. You’ve got ports on the back of the pump. You see here we’ve got an inlet. This is where the hose comes from, the tank that feeds this unit. This is our tank port. I can cover this one in a minute. And this is our cylinder port. So basically your oil comes in gravity fed, and your pressure goes out to the cylinder, to your hoist cylinder, comes back into return and goes back to the tank. We recommend in all of our systems that you run this third line sleeve where the sleeve comes and is packaged with every pump that we sell. You put it in the inlet, it goes in and it sits in there right into the spot. Putting that pump sleeve in the inlet changes the internal workings of the pump, the plumbing. And what that does then is we open up this port, which is labeled as tank, and we plumb that back to the reservoir, always plumb your line back into oil, don’t have it plumb in from above and splash down creates bubbles. You get those into your inlet and you get cavitation. So what we do then is now we have our oil coming into the pump. We have our oil going out to the cylinder. We’ve maxed out. For some reason we’re into relief either at the top of our cylinder or the load is much heavier than we thought to lift. And it just doesn’t have that kind of strength. So what happens then is your pump will start to go into what we call bypass or relief mode. This pump is 27 gallons a minute. All of a sudden we’ve got 27 gallons a minute going through the internal workings of this pump, through pouring about the size of the head of a pen where the dump pumps have gone from there.

Different things have popped up in the industry, different types of transmissions, power take off changes, and that’s caused some some issues. And the first of those issues I’ll get into is the spline. So you get into situations now where maybe we’re dealing with a Mack that has a PTO mounted on the back of it. The cheapest option for those Mac transmissions or the Volvo is to have a power take off. That is what we call DIN 5462 mount. So this is a 36 millimeter by eight spline, four bolt mount, and it’s pretty robust and it helps bring the cost down because of the PTO only has that same mount and doesn’t have adapters in it, which would be needed to make it go to the 7/8-13. Like our assortment here has. So this is a change that came out.

So not all dump pumps are the same. Sometimes you’re going to have to actually separate the dump pump from the power take off when you’re when you’re calling in or trying to identify what you have. Because as you can see from the flange back, very similar in their outward appearance. But definitely if you get this 8 spline and you needed a 13, you’re going to have some issues.

So this is the part of the industry where we’ve had the greatest amount of change, and this is the automatic transmission and hydraulics for automatic transmission. So our power take offs have change. We’re all aware that the PTO is now come with a clutch pack. So what else does that represent for us? A little change. There’s not much space in alongside some of these automatic transmissions. So this again, this would be sort of the original. This is the G102 style pump. It was a smaller version of the C102, which was the granddaddy of all dump pumps. But the G102 was much smaller. So it would for the longest time is the only pump really that would fit alongside of, say, an Allison 3000 or 4000 transmission and be able to direct mount it. The migration that I notice first and we jumped on was Parker’s version of the C102.

They call it the slimline the SG 102. And what happens with this pump
is that it’s narrower to fit in alongside of the transmission and whatever
you have here on the frame rail. So this was the only pump made for that
type of application for the longest time. And we stock these regularly and sell
quite a few of them and install quite a few of them.

We’ve also run into some other situations
where there’s more equipment mounted on the truck side from the OEM making it
even difficult to mount some of these. Permco has this one called an MVP,
which is a modular design of a dump pump. So it’s direct mount 7/8-13 spline
or four inch pilot and four bolts. So we know this is our SAEB
and these all turn clockwise clockwise rotation
because it’s on an automatic. And what they’ve done here
is there’s the basic pump and we install this on on the power
take off on the transmission. And then what they’ve done
is they’ve separated the valve, as you can see on our other dump pumps. The valve was molded
right to the pump casting. In this case, it’s separate. It looks like it has an SAE code 61 style flange that we use. Ships
with the O-ring ships with this intact, you have to take it apart out of the box and then you assemble this
onto your power take off that’s on the transmission,
and then add the valve. Be careful of the O-ring, I lost it once myself,
but the O-ring goes right in there. You tighten those down
to the right torque specs and it simply attaches to the side. And again, a much more streamlined
application for your Allison to allow you to get a pump in there
where we had or 15 gallons a minute. These can come as high as 27 gallons
a minute in the flow. 

All right. Our next option that we have is sometimes
you can’t fit either of these in here. So what the industry has done is
they’ve taken the valve that, again, you normally see
on our regular dump pumps, and it allows you to mount
any sized gear pump that can fit. So you’re going to want to
maximize that size if speed is your issue. But at the same time, make sure you’ve got
the clearance to get away from whatever is preventing you
from entering the out of the box solution. So you would put your gear pump on there,
same as you always would up on the power take off. And all we’re looking at here is a remote
mounted dump pump valve, right? It’s air shifted, Works the same way, It’s just like taking the valve again
off of the side of your dump pump and just making it remote mounted so you can mount
that anywhere on the truck. The Gemini pump from Perm
Co is a dual pressure pump. Some guys will call it dual stage. It’s dual dual pressure. And I mentioned this one here
because we use these both on the standard and the automatic
transmission applications. You can see the outward
appearance on the Gemini is different by the cylinder on the back. These are used on your walking floors
or a live bottom or a belt trailer, as we call them, and it allows you to run
your dump system at your low pressure. 2100, 2200 PSI. And on the high side,
if you’re running a walking floor or a live bottom,
you’re going to need 2800 PSI. That’s all done right through here. You’ve got a pneumatic selector
in the cab, and it’ll select one of the two settings,
your low setting in your high setting. But one of the other systems that offers a few more choices
and a greater gap in the pressure settings between low and high is our what
we call the combo valve or a dual pressure relief valve
that has a tipping feature. So in here we have a single acting
cylinder spool, which is the same kind of spool that’s in here,
and that’s for controlling the hoist. This table is filled
with the heavy lifters. This is where the work gets
done. This is your muscle to make it operate as efficiently as possible
in the way it was engineered to. 

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you navigate these tricky waters to pick the best
selection that works for you.