oldtech

Hi Ranger bucket lift - again

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A while back I had posted that I owned a 1986 Chev C70 with a Hi Ranger bucket lift on it that I use for farm building maintenance.

I noted that there were some people here that were very familiar with that type of lift....

Well, yesterday the hydraulics stopped working so maybe I can ask a little help in diagnosing the problem?

This has controls in both the basket and the base which I think is the usual.  only plastic and hose lings run to the basket which use the oil to operate the levers and the on the base.  You have to pull the trigger on the joystick handle to activate any of the three directions UP DOWN , rotate and extend.  On the base you mush push a button which is apparently a relay to a solenoid on the hyd switches.

Usually when you pull the trigger and do anything with the directions the system squeals and starts to move.  Now we just hear a click and there is almost no change in the pressure according to the gauges.

Can anyone tell me what to look for here?  It is the relay solenoid?  I THINK it works by constantly dumping oil to the reservoir until the solenoid closes the dump valve and forces pressure into which ever line is open.  Looking for parts or service or both too.

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I've got a bucket truck as well It's a C70 with a Powers Sky Master lift. I've never found any information on it. It seems to be ex military as under the paint it's OD.

A couple of weeks ago it stopped working and I found the pump shaft key had just given up. Both the pump shaft and the PTO are quite worn but a new key got it working. I never go up in it any more without my harness and 100' of 11mm climbing rope and a belaying rig.

No electrics at all on mine so I'm no help.

I'm looking for info on mine so, not hijacking, but if someone knowledgeable on these things responds I'll tag along.

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No problem!

This has hydraulic tubes that go from the joy stick down to the actual valves in the turret base.  When you move the stick it moves the handles on the base but you have to squeeze a trigger to get it to activate which is a solenoid type valve that shuts off the dump flow and pressurizes the valve bank.  There is a corresponding red button on the bottom and a fused circuit to it.

You can hear it click when you pull the trigger in the bucket and then the hydraulics start squealing as you move the stick.

Only in the middle of using it it just started to slow down and not respond the other day.  Im just looking for confirmation of my theory of operation here and how to find parts or service info for it.  Lots of good mechanics on this page!

We are not going up higher than a 30 foot ladder would go while working on the siding on my house so Im not too concerned about getting down but dont like anyone working alone without someone on the ground in case of emergency.

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Mine has the control tubes - I replaced all of them last year as the squirrels gnawed through them. No joystick but three levers for both booms and swing. The hydraulics on mine are always pressurized with a reducing regulator for the control pressure. 

Mine started moving slowly  but only from the remotes in the bucket. I removed the regulator valve spool and cleaned it without moving the pressure setting and it restored normal movement. I have no idea what the control pressure should be but it has to be less than the air brake type tubing can take with hot oil in it.

Speaking of hot oil: Mine seemed too hot. 5 gallons in the reservoir, the turret base, cured that. Again, I have no idea how much should be in there. That was slowing it down a bit as well.

It sounds like yours has an open center system that pressurizes electrically. Can you identify the solenoid valve and confirm it's moving?   PTO pump? Pump turning?

PITA working without a manual.

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I have been in a bucket that has the switches like yours, only difference was that the switch controlled an electric booster pump. The engine driven pump ran all the time and was somewhat slow. The electric pump would boost flow to give you more speed. It does make a squealing noise. I would check the oil level as well. 

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I'm not familiar with your exact setup but I've worked on crane hydraulics for many years. 

If you have a valve that dumps your pressure when not energized and blocks the dump when you push the joystick button you should go to that valve and do some investigating.  

I'm assuming the pump is run off a PTO and not off an electric motor

you can put an ohm meter across the coil terminals and check it.  

You can usually pull the coil off and remove the spool from valve block. 

Then put the coil back on and with engine off / key on you should be able to hit the trigger and see the valve clicking back and forth.  It might need cleaned 

 

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2 hours ago, 12_Guy said:

I have been in a bucket that has the switches like yours, only difference was that the switch controlled an electric booster pump. The engine driven pump ran all the time and was somewhat slow. The electric pump would boost flow to give you more speed. It does make a squealing noise. I would check the oil level as well. 

Its interesting that you mention a booster pump.  Maybe thats what this is and explains the squeal?  I cant see any pump inside the pedestal though.  Maybe its underneath?

The model # is a 4E-35PMI

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PM ME  I OWNED A HIGHRANGER

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Spoke to the guy at UTEP and he also thinks that its the solenoid coil.  There is a manual override button on it to close the valve to get the boom down in emergencies so he said to try pressing that and see if the gauges pressurize.  I will keep you posted!

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I ran a 6H-65PBI for three years. It was closed center hydraulics, I believe yours will be with the pilot controls. When it was new we had problems with it randomly shutting off. It was a loose wire on one of the brushes of the slip ring at the bottom of the hydraulic rotation block. We would press the button on the solenoid to make it go. Later in its life (about 15 years) when it didn't get used much, there was a problem with corrosion on the slip rings that would stop it. There again pushing the button would make it work. 

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With the help of some phone support from the shop have determined that the problem is the main pump.  Most likely the splines on the shaft are stripped.

So... we will have to drain the system and yank the pump.  They said they could replace the shaft and the female coupling in the drive housing for around $500.  Not too bad I think considering how valuable that machine is to me!

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On 11/3/2017 at 6:56 AM, 12_Guy said:

I have been in a bucket that has the switches like yours, only difference was that the switch controlled an electric booster pump. The engine driven pump ran all the time and was somewhat slow. The electric pump would boost flow to give you more speed. It does make a squealing noise. I would check the oil level as well. 

All of this talk about an electric pump......

I think that you are referring to an electric backup pump that is designed for emergency usuage in the event that the main pump dies.  My observation is that the main pump should be a LOT faster than the wimpy backup pump.  This would lead me to think that your main pump is not putting out full flow for whatever reason.  Including a possibly stripped drive.

With ANY direct coupled PTO lubricant should be added to the splines periodically.

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19 minutes ago, 1586 Jeff said:

All of this talk about an electric pump......

I think that you are referring to an electric backup pump that is designed for emergency usuage in the event that the main pump dies.  My observation is that the main pump should be a LOT faster than the wimpy backup pump.  This would lead me to think that your main pump is not putting out full flow for whatever reason.  Including a possibly stripped drive.

With ANY direct coupled PTO lubricant should be added to the splines periodically.

There is no electric backup on this one though I wish there was!  I did find out from the shop tech that there is a way to manually close the activation valve should you lose power to the solenoid though.  There is a button on top of the solenoid that lets you run it but its REALLY hard to get at and recessed too.  You need a long screw driver to do it.

Im not at all sure that any of them really has an electric pump though.  The solenoid makes a noise like it is a pump when activated and kind of looks like a small electric motor.  But all its really doing is diverting fluid into the valve bank.  But with no pressure from the pump nothing is going to happen.  

Have to see if I can use a come-along to retract the boom to get it into the shed.  It will look kinda silly with it sticking out the door like that.  Also hoping for not too cold weather to get under there and remove the pump.

As for lubing the splines, there is no way to do that as it is all completely encased in a housing.  There is no PTO shaft on this one.  Its mounted in a housing like a really big starter!

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Electric backup power on a hydraulic lift is always an extra cost option. If the person who spec's the truck is cheap it won't come with one. I have a friend with a small lift that is only electric, he uses two group 31 batteries.

with the Hi Ranger I ran, the solenoid button was hard to push. I would use a hammer with the handle on the button and lean on it with my hip

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8 hours ago, chip man said:

Electric backup power on a hydraulic lift is always an extra cost option. If the person who spec's the truck is cheap it won't come with one. I have a friend with a small lift that is only electric, he uses two group 31 batteries.

with the Hi Ranger I ran, the solenoid button was hard to push. I would use a hammer with the handle on the button and lean on it with my hip

On mine the button is not physically hard to push but it is recessed into the top of the solenoid and that is buried inside the rotating pedestal.  Its actually kind of dangerous because the only ways to press it are to get down and extend your arm up through the service door or use a long screw driver from the top next to the main lift cylinder.  Have not had to use it but Id be worried about getting pinched while using it!

Sure with I had electric back up on this because I might be able to finish my project and deal with the repairs next year in warmer weather!  :(

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The electric backup is meant for stowing the lift in the event of failure of the primary power source. They usually have a 25% duty cycle.

Have you tried to pull the pump off the pto? Is it a spline drive or a key? I know of one time when the spline stripped and the crew pulled the pump off and jammed the broken off end of a chainsaw file in the splines as they put the pump back on. It lasted three weeks.

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2 hours ago, chip man said:

The electric backup is meant for stowing the lift in the event of failure of the primary power source. They usually have a 25% duty cycle.

Have you tried to pull the pump off the pto? Is it a spline drive or a key? I know of one time when the spline stripped and the crew pulled the pump off and jammed the broken off end of a chainsaw file in the splines as they put the pump back on. It lasted three weeks.

No not yet.

I gave the model and SN to the shop and they told me it is a spline so we have to drain the system and pull the pump and the cowling with the female coupling in it and bring it all in.

Thats a pretty creative fix!  When we yank it Ill see if it makes sense to try but I think we will just run it in.  If I have to I can leave the last of the siding work til spring or maybe we will get some warmer weather again yet...  Optimism!

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On 11/4/2017 at 10:12 AM, oldtech said:

As for lubing the splines, there is no way to do that as it is all completely encased in a housing.  There is no PTO shaft on this one.  Its mounted in a housing like a really big starter!

What I do to lube the splines on my direct mount PTOs is to unbolt the pump from the PTO, slide the two apart, lube the splines, and bolt the two back together.  Much easier done on a lift perhaps, but I do it on the ground and manage.  No, I do not drain the pump or disconnect the hoses, but I do hang the pump from a rope sling/ratchet strap/etc. so as not to put strain onto the hoses.

There is a unique type of wear that these couplers experience where the heat differential between the PTO and the pump creates a sliding action between the male and female splines, which under load can cause catastrophic wear.  Grease is cheaper and usually easier than parts is my motto.

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36 minutes ago, 1586 Jeff said:

What I do to lube the splines on my direct mount PTOs is to unbolt the pump from the PTO, slide the two apart, lube the splines, and bolt the two back together.  Much easier done on a lift perhaps, but I do it on the ground and manage.  No, I do not drain the pump or disconnect the hoses, but I do hang the pump from a rope sling/ratchet strap/etc. so as not to put strain onto the hoses.

There is a unique type of wear that these couplers experience where the heat differential between the PTO and the pump creates a sliding action between the male and female splines, which under load can cause catastrophic wear.  Grease is cheaper and usually easier than parts is my motto.

Yes, its very similar to my Mercruiser boat out-drive which Merc has a special kind of grease for.

In this case the unit gets only occasional use so I think that putting it back together with a good greasing will probably outlast the rest of the truck but I will ask the shop if they have any special grease or if they can recommend anything.

I will have to take the hoses off because now it has to go in and get repaired.  Im guessing there is at least 10 gallons of fluid in it, right?

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