DUMP TRUCK

[PEM]

1995 FORD F450 V8 7.5 DUMP TRUCK

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I just purchased the truck at a state auction, runs good, but I can't get the dump to lift. The trunk dumper package was, I think, orginally installed by Crysteel (or Crysteel equipment dealer), sticker adhered to the dump bed.
I know that the dump system works with a transmission driven hydralic pump.
I can't see the cylinder/s because I can't get the lift to work. The pto is engaged via a pull lever by the driver seat, and the dump is operated via a forward/backward lever mounted on the vehicle hump. When I pull the pto lever and pull the dump lever forward or back I can hear some noise coming from the hydralic pump. Either the pump is bad, or I don't know how

 

[beenthere]

First check if oil is in the tank.

If it is, then sounds like you will need to crawl under and see if the pump is turning when the PTO is engaged (and you have to put the clutch in to engage the PTO, not just pull on the lever).

If it is, then find out if the valves are diverting oil to the cylinder (may need to install a pressure gauge to check out the pressure).

If you have pressure, then find out what is wrong with the cylinder.

A good project ahead for you.

 

[EddieWalker]

You are going to have to start out with the basic. Is there oil in the pump? If there is oil, is the pump building up pressure? If so, then it's the seals in the cylinder. If not, then you need to find out why there isn't any pressure. Is it the pump or the drive shaft that turns the pump? Don't assume anything. Just because the drive shaft is turning doesn't mean that it's not spinning on the shaft coming out of the pump. Double check everything.

I have a F600 Ford dump truck and its an ongoing, never ending project. Hope yours is better then mine.

Eddie

 

[PEM]

Thanks for the suggestion. I have been told the hydralic fluid tank is under the dump bed-don't see it anywhere I look for it.

 

[EddieWalker]

On mine, the cylinder is the storage tank. It is in the top half of the cylinder, above the piston. There is a sort of bolt think that you unscrew to add fluid on the cylinder. At one point, sombody cut a hole into the dump bed to get to it and then welded it back on. I guess that they had to do that to lift the bed, but it's only a guess.

Eddie

 

[AlanB]

Did you push in the clutch before engaging the PTO?

Chance you can pull down to the state garage and ask if they are familiar with it, and what they know. Those guys have been very helpful to me in the past. (My state and County guys I mean)

Good luck.

 

[mas1237]

I've got a Ford 1979 F700 dump truck. The clutch pedal must be to the floor to engage the PTO for the pump. Let out the clutch. Then pull the Knob connected to the cable that diverts the oil flow at the pump to raise the bed.

The pump is a gear pump and is virtually indestructible. To drop the bed, I push in the knob, which lets the oil from the lift cylinders flow back into the reservoir. The reservoir is located between the frame rails immediately behind the cab. The only way to check the oil reservoir or to fill it is to have the bed in a raised position.

You may have to hook a chain to the front top of the bed and to a tree. Then ease the truck forward (while the knob is pulled out so as to not create any resistance) to raise the bed so that the safety bar can be locked in place. This should allow you access to the pump reservoir along with easier access to the pump.

I found out that with short dumping cycle times; i.e. every 12 minutes, I had to go to heavier weight oil here in North Florida during the summer. I drained out the 70 or 80 wt oil and went with 140 wt. I've used it this way every since. I wouldn't recommend using 140 wt if you were in cold climates or planned to use your truck in the winter, but for hot summer temps and short cycle times, it solved my problem of the oil heating up and thinning, which required reving the truck engine to get sufficient flow rate to raise the bed.

 

[2458n]

The shiftcable on the "hump" was not working on my Crysteel system. This is on a 1996 Ford F-350. Everything was okay except moving the valvebody. The best advice is checking with the maintance dept of who sold it. Many times you will get a complete service record. Crysteel was very helpful in locating the needed cable.