Weak dump hoist help!

[CaPowell]

Hello all. I recently purchased a chip truck and finally got to use it today. I've had the bed up and down fifty times working on various things, but today was the first time I tried dumping with a load of chips. It didn't go well! It wouldn't even try going up until we had pulled out almost half of the load. The cylinder is leaking a little (would this affect lifting power?) and I'm trying some Blue Devil in it before I shell out more money. It is a Rugby LR165 hoist, which should have plenty of umph to lift 9000 lbs.

Also, until I can get this fixed, what is the best tool for scooping out chips quickly?

Thank you!

 

[Reach]

So I have a couple thoughts. First, I must presume it has an electric hoist, and not PTO? And I must assume you’ve checked the oil and it’s full?

Assuming it’s full of oil, yes, a leak could affect the lifting power especially if the internal packing is allowing fluid to leak from one side of the piston to the other under load. Easiest way to check that is to raise the bed, preferably with some weight, and let it sit overnight; see if it moves at all. If so, you’ve got a leaky packing or valve somewhere.

Also, the pump could be wearing out, especially if it has a leak - run those pumps dry a couple times and you can damage them terribly.

Another possibility is the relief valve - could be faulty or could be set too low somehow. That’s best checked at a hydraulic shop. They can also check the pressure of the pump to make sure it’s actually making what it should. Probably that will be a cheap check for them to do, likely even free if you have a decent relationship with them.

As for part two of your question, I like either a plastic grain shovel or a short handled manure fork for moving a lot of chips in a hurry. The manure fork may be the best bet, as it is wider, but if you’re making real fine chips they may want to fall through the tines.

 

[CaPowell]

So I have a couple thoughts. First, I must presume it has an electric hoist, and not PTO? And I must assume you’ve checked the oil and it’s full?

Assuming it’s full of oil, yes, a leak could affect the lifting power especially if the internal packing is allowing fluid to leak from one side of the piston to the other under load. Easiest way to check that is to raise the bed, preferably with some weight, and let it sit overnight; see if it moves at all. If so, you’ve got a leaky packing or valve somewhere.

Also, the pump could be wearing out, especially if it has a leak - run those pumps dry a couple times and you can damage them terribly.

Another possibility is the relief valve - could be faulty or could be set too low somehow. That’s best checked at a hydraulic shop. They can also check the pressure of the pump to make sure it’s actually making what it should. Probably that will be a cheap check for them to do, likely even free if you have a decent relationship with them.

As for part two of your question, I like either a plastic grain shovel or a short handled manure fork for moving a lot of chips in a hurry. The manure fork may be the best bet, as it is wider, but if you’re making real fine chips they may want to fall through the tines.

Thank you. Yes, it is electric.

That gives me some starting places to look into.

 

[Tom Dunlap]

In the winter chips would freeze onto the inside of the chip truck. The SOP was to dump and scrape every night.

Sometimes the chips would freeze into a nasty crust on the bottom of the box. After messing around with various shovels I made up a scraper out of 3/16" sheet. It was about 15x8 The handle was made from large electrical conduit. I fabricated a ferrule and pin arrangement so it could be broken down and stored. If you lay a scoop shovel down, step on the shovel and look at the angle of the handle you'll see an angle. The ferrule on my scraper was not straight,in line with the scraper blade, I guess it was about ⅓ of the angle of the scoop shovel

Chips would be dumped then the box left up. The driver would use the scraper to encourage the frozen crust of chips to slide off. Having thee long handle on the scraper made it a quick job.

 

[Merle Nelson]

To empty the back part of a truck quickly, and top part of the front.....a potato rake. A pitch fork like tool with tines bent to 90°. Longer tines so you get a full purchase. I think 9 inches is good.

You're not lifting the chips, just forking down and dragging back out - very quick.

 

[Treetopflyer]

Look for the thick cables and grounds from battery and such and verify the connections are clean and not corroded. You lose lots of voltage through poor wiring as well. We have an Isuzu chip truck with similar issue and it was due to old wires and connections that were is poor shape. As well some pumps have inner screens that collect debris inhibiting good fluid flow I've been told.

 

[Stumpsprouts]

I just gotta say, dang that sucks. I feel for you bud! Hope you get it fixed.

 

[Tom Dunlap]

Look for the thick cables and grounds from battery and such

Clean contacts then apply a generous covering of dielectric grease or silicone.

Corroded grounds are usually the source of glitchy electrical issues.

Prop the box up if you're working under it

 

[CaPowell]

For those who are interested, I took the truck to a trailer/truckbed shop today. Two guys came out and looked and said the lift was set up WAY too far forward. They are going to try moving it back at least a foot next week and seem to think that will make a substantial difference in the lifting capacity. According to them, each inch you move the lift back equates to a couple hundred lbs of added lift capability. Hopefully they are right. They seemed to think the problem was not with the pump or cylinder.

 

[Reach]

When you say “forward”, do you mean closer to the rear bumper, or the front bumper of the truck? If you move the hoist backwards (towards the rear bumper/hinge pins) you will decrease the lifting capacity, not increase it.

 

[Jehinten]

When you say “forward”, do you mean closer to the rear bumper, or the front bumper of the truck? If you move the hoist backwards (towards the rear bumper/hinge pins) you will decrease the lifting capacity, not increase it.

My thoughts exactly. Moving it towards the hinge pin would give it a higher dumping angle, but weaker lifting capacity.

 

[CaPowell]

When you say “forward”, do you mean closer to the rear bumper, or the front bumper of the truck? If you move the hoist backwards (towards the rear bumper/hinge pins) you will decrease the lifting capacity, not increase it.

That's what I thought too, but these guys were adamant. I better do some checking first, huh?

 

[Reach]

That's what I thought too, but these guys were adamant. I better do some checking first, huh?

Yes, I think I you should. As Jehinten said above, the closer to the hinge pins the hoist sits, the higher/steeper the bed will go, but the less weight the hoist can lift.

 

[evo]

That's what I thought too, but these guys were adamant. I better do some checking first, huh?

They are full of shit. Think of leverage and fulcrums. The closer you move the power to the pivot the more weight it has to lift.
Think of a wheel barrow, the longer the handles the easier it is to lift. Might not dump well, but easier.
Power and total lifting height is a balance.
Sounds like there is one of three things going on, first two is a miscommunication.
#1 maybe you interpreted what direction they are moving it wrong?
#2 maybe they misunderstood your problem, thinking the box doesn’t lift high enough to get all the chips out
#3 they are wrong entirely or ripping you off

#2, and #3 your better off finding someone else

 

[Phil]

As well some pumps have inner screens that collect debris inhibiting good fluid flow I've been told.

This was the issue for my little 1 ton dump years ago. I took the cylinder in to get rebuilt and still had issues. Ended up pulling the pump and reservoir off and cleaning it out. Sometimes water can get in the reservoir and gum up the screen. Its something easy to check.

 

[CaPowell]

This was the issue for my little 1 ton dump years ago. I took the cylinder in to get rebuilt and still had issues. Ended up pulling the pump and reservoir off and cleaning it out. Sometimes water can get in the reservoir and gum up the screen. Its something easy to check.

I think the placement is fine and am now leaning towards just replacing the pump, but I think I will do this first.

 

[CaPowell]

They are full of shit. Think of leverage and fulcrums. The closer you move the power to the pivot the more weight it has to lift.
Think of a wheel barrow, the longer the handles the easier it is to lift. Might not dump well, but easier.
Power and total lifting height is a balance.
Sounds like there is one of three things going on, first two is a miscommunication.
#1 maybe you interpreted what direction they are moving it wrong?
#2 maybe they misunderstood your problem, thinking the box doesn’t lift high enough to get all the chips out
#3 they are wrong entirely or ripping you off

#2, and #3 your better off finding someone else

I think it is #3. It's just weird because I thought they were a solid business and they were so adamant.

 

[evo]

I think the placement is fine and am now leaning towards just replacing the pump, but I think I will do this first.

Next time it’s up, take a pic and post it here

 

[treesap]

I would check

• wiring for loose connections, corrosion, and bad grounding
• check the hoses for leaks
• make sure your alternator is putting out good current
• lift the bed with as much load in it as possible, and let it sit overnight, if it leaks down you have a bad seal most likely in a hose connection, or the piston itself, possibly the valve

if your alternator isnt outputting enough current, your pump wont get enough power, causing the motor on it to not have enough torque to pump the extra pressure, and a leak will obviously let pressure out as well

 

[CaPowell]

So, for anyone wondering how things turned out, I put a new pump on it last Friday and that seems to have fixed the problem.

My knowledge of hydraulic pumps is very limited, but after installing this, I'm not sure how the old one was working at all. The old one was power up/gravity down, but it was hooked up to the cylinder with two hoses like it was double action (the hose going to the top of the cylinder wasn't doing anything?). The old one also only had a positive cable going to the battery. I had to go buy a 12 ft cable to hook up the negative. That doesn't seem normal to me...

They're a little late now, but here are some pics for those wondering about the bozos saying the hoist was too far towards the front of the truck.

Thanks again for all the help and suggestions everyone offered!