Archived Truck dump body won't come down!

[FATCAT]

Folks I have a problem.



My 4500 dump body won't come down.



It is a power up and power down electric unit. I can raise the bed, but when I hit the button to lower the bed it won't come down.



When I hit the power down button, the pump starts working, but nothing is happening. Needless to say, I am stuck (at least it is in the driveway and not on the road).



Anyone have any advise as to what to look for? Selonoids bad on the down side? Is there any way i can deactivate the power down mode an let it come down by gravity?



Help!

 

[tp0d]

Got any model#'s off the power unit?

Did you raise it to the max point? Might need a push with the pump running in down mode. Maybe a rope on the highest point, and pull down on it. .

good luck

-j

 

[FATCAT]

Got any model#'s off the power unit?



Did you raise it to the max point? Might need a push with the pump running in down mode. Maybe a rope on the highest point, and pull down on it. .



good luck



-j

The pump unit is a SPX Stone. I believe it is model DC-41DT

There is link to the specs:

http://stonehydraulics.com/catalog/99-2007.pdf



I did not raise it to max point, but only about a foot or two from max point.

I have a come-a-long and will try that tomorrow, but i hope there is a way to somehow lower it without doing that.



It seems like the valve that opens to allow the fluid to flow back into the tank is not opening.

 

[Sticks]

Yeah, sounds like the valve is stuck. If push comes to a shove, put a bucket under the cylinder and crack open the hydraulic fitting either at the point where it goes to the bottom of the cylinder, or the same hose at the valve.

And when I mean crack, I mean loosen it just enough for fluid to start a rapid drip or small stream and let it bleed down. DO NOT ATTEMPT TO REMOVE HOSE WITH THE BED UP!!!

You should be able to manually stroke the solenoids, but without being able to see them, not much I can do. Check to make sure you are getting voltage at the solenoids (#18) when you are pushing the down button. One line should be hot, the other ground. Note you could have a bad ground ergo the coil will not close.

Be smart about how you work on this, as in do not put yourself between the frame of the truck and the bed!!!

 

[NIsaacs]

Might be a small amount of ice somewhere in the system. Can you put a space heater on or near the pump controls?



Nick

 

[FATCAT]

Sticks;

thanks for the info. It is now morning, the rain stopped, and the sun is up so I can see something. I'll test the solenoids first. There is some rust at the connections I did see last night, maybe I will clean up all connections and then test. Then if need be, crack the hose fitting and lower the bed down on some 4X4's to releave the pressure and keep the bed up in case i need to remove a hose or replace the solenoids.



Temp has been above freezing for past few days, so I don't think there is any ice in the system.

 

[jhenderson]

Check the connections inside the control. I have had a wire come loose inside my hand held and have had the same symptom. No power to the solenoid.

 

[FATCAT]

Check the connections inside the control. I have had a wire come loose inside my hand held and have had the same symptom. No power to the solenoid.

I check all the connections and cleaned up a few.

When I hit the down button, the pump runs and I can see that the dump bed tries to move down about 1/2" and then stops.



So there must be power going to the solenoid/cartridge.



The exact pump I have is a SPX Stone model DB-1696 made for AirFlo Equipment, but I can't find any schematics on the thing on the web other than a parts list.



Looks like my truck is out of commission until I can get some parts.



I don't want to bleed it down all the way because with my luck I won't be able to get it back up to work on the pump. :{

 

[jhenderson]

Don't assume anything! Check at the solenoid with a test light. Also check the ground at the solenoid.

 

[FATCAT]

Don't assume anything! Check at the solenoid with a test light. Also check the ground at the solenoid.

Did that today. My machanic buddy came over today and we did the test light and there is power to the solenoid and all connections are clean and working.



The solenoid must be dead.



Almost impossible to find parts for this pump even though it is only 4 years old. The price list for parts for this pump have the solenoid at $165! I was figuring on getting two just in case the other one goes, but looking at that price I couldl get an entire new unit from KTI for $300 delivered!

Premium Supply - Double Acting Hydraulic 3qt KTI Pump



I'll contact the company who installed the dump body tomorrow to see what they can do for me. I'll probably crack the solenoid nut just a little tomorrow and let the dump body drain down slowly then retighten the solenoid and get it over to my dump body guy some time this week hopefully.



Thanks for the help.

 

[HHhuntitall]

Hmmm. I work on these all the time. I use them for bale beds pretty regularly, and it sounds like you have a solenoid stuck. If the bed is moving just a slight amount, I'm guessing the return solenoid, the up solenoid in this case, is stuck in wrong direction. If you are getting electricity to both wires on the solenoids, the unit is grounded good, which should be if the pump is running, then I'd suggest tapping on the solenoid or replacing it. I'd have to have a full drawing to tell you which direction they need to be and which one is acting up... ..... you dump body guy should be able to fix it pretty quick, and it should be a simple fix.



The biggest problem I see with these units are either rust or foreign matter in the system. If the solenoid moves with rust in the bore or some foreign matter, it will wedge and stick, not being able to move back, keeping fluid flow from coming in that direction. Usually, hydraulic pressure will move it, but sometimes... ... ...

 

[FATCAT]

Hmmm. I work on these all the time. I use them for bale beds pretty regularly, and it sounds like you have a solenoid stuck. If the bed is moving just a slight amount, I'm guessing the return solenoid, the up solenoid in this case, is stuck in wrong direction. If you are getting electricity to both wires on the solenoids, the unit is grounded good, which should be if the pump is running, then I'd suggest tapping on the solenoid or replacing it. I'd have to have a full drawing to tell you which direction they need to be and which one is acting up... ..... you dump body guy should be able to fix it pretty quick, and it should be a simple fix.



The biggest problem I see with these units are either rust or foreign matter in the system. If the solenoid moves with rust in the bore or some foreign matter, it will wedge and stick, not being able to move back, keeping fluid flow from coming in that direction. Usually, hydraulic pressure will move it, but sometimes... ... ...

Yeah, we were wacking the solenoid with a hammer a bunch of times with no success ... like you do with a starter that sticks sometimes.



I hope when I crack the nut on the solenoid to drain out the fluid to let the bed come down, any crap will flow out with it.



I just want to get this thing fixed ASAP ... hate not being able to drive the truck. #@$%!

 

[Sticks]

You are either going to need the number in the description for the valves, or the numbers stamped on the valve body. Once you get one out, you can call around to various Hydraulic parts shops with the brand on the valve and the number to find a replacement.

On edit - you might want to look into putting in a 10 micron filter on your return to tank side. Most hydraulic fluids are only 20 -50 micron absolute at best. Maybe even switch over to a 10wt drive train oil with a high zinc content.

I hate knowing what I know.

 

[HHhuntitall]

The problem you have with a return line filter is the specific return on these systems is enclosed inside the small tank right next to the pickup. The two lines act as pressure up and down, and the return is in the head just inside the solenoid valves, returning to the small tank, right next to the draw tube. The only way to filter the return would be block the regular return in the tank, and open up an optional return, if available, and plumb that back into the tank from another direction. It's a good idea, but difficult to implement on these systems. These systems are designed to be cheap and they function off the idea that no foreign matter can be introduced to the closed system... . which is great is it was spotless when it was put together, and nothing comes apart while in operation... ... They're really not designed for the high cyclic rate a lot of people use them for, and if you're going to run one, I suggest using a hydroscorbic hydraulic oil that absorbs and hold moisture to help prevent rusting.



As an afterthought, I've looked at installing a pickup tube filter on these to help with problems just like this. The problem is that the tank is so small, it's difficult to find anything that will work for any period of time that will fit in the tank. Then it's difficult to access for service. The later models with the plastic, clamp on, tank appear to be easier to modify. The earlier models with steel tanks are next to impossible to add anything to on the inside.

 

[FATCAT]

Folks, I got the problem fixed.



I contacted the guy whos company installed the body and he said it was just the electro magnetic solenoid around the valve body that was bad. He said he sells a couple dozen a year and hardly ever sees a valve go bad.



So I stopped by today and picked up 2 of them (one for when the other one goes) and spent 5 minutes installing it over the valve and BINGO! it worked!



Thanks for the replies and the help.



I guess the moral to this story is to keep a spare solenoid in the glove box for just such emergencies.

 

[Sticks]

Glad you found the problem.