Terex benford hd1000 hydrolic won't lift or tip

[Mick-the-fitter]

The system doesn’t work very well with a leaky tank cap, the hydrostatic trans works separately to the lift/ tip and steer, although it uses the same oil! Try taking the hoses off the steering ram and blanking them off, the steering wheel will now only turn a small way each way. If it turns all the way round still, the relief valve is open to tank, try tipping!

 

[Bob dale]

The system doesn’t work very well with a leaky tank cap, the hydrostatic trans works separately to the lift/ tip and steer, although it uses the same oil! Try taking the hoses off the steering ram and blanking them off, the steering wheel will now only turn a small way each way. If it turns all the way round still, the relief valve is open to tank, try tipping!

Thank you for your info I’ll try in the morning is it a pressurised system and does it make a difference if the filter is in or not . I no it’s to keep oil clean so no crap goes past but does it make a difference to the pumps thanks bob

 

[Mick-the-fitter]

Can’t remember if you have a double filter system, one for the hydrostatic and one for the hydraulics, but the hydrostatic is a semi sealed system, it uses the same oil to go from pump to motor and back, but via the top of the tank to ensure the system has no air, as this has forward and reverse, the tip and steer is a separate issue.

 

[Bob dale]

Can’t remember if you have a double filter system, one for the hydrostatic and one for the hydraulics, but the hydrostatic is a semi sealed system, it uses the same oil to go from pump to motor and back, but via the top of the tank to ensure the system has no air, as this has forward and reverse, the tip and steer is a separate issue.

Hi thanks for your info some one on here said he thinks it’s got a separate filter but I have looked all over it and nothing thanks bob

 

[Mick-the-fitter]

Take the cap off the tank, and take a pic!

 

[Bob dale]

Take the cap off the tank, and take a pic!

Ok will do

 

[jd6820]

On a HD1000, you'll find the pump that drives the steering and tip hydraulics is bolted to the engine near the fuel injection pump. Chances are that is worn and changing the oil has caused it to air lock. When they are worn they don't self bleed like they should. I'd check the suction lines for leaks (the big pipe into the pump) if no leaks are found try slackening the pressure pipe and crank it over and let it run till oil appears at the fitting. This should give the pump enough to prime the rest of the system. If the hydraulics are still weak or get worse when they are warm. The pump will likely need replacing. Can't say I have had many relief valve issues but I suppose there is a small chance that could be the case. But you'd likely have other symptoms... The tank filter is a return filter for the main hydraulics I'd get this replaced at the soonest available opportunity. The other filter is under the footplate near the steering column.

As others have stated above, this pump is independent of the main drive pump bolted to the rear of the engine and driven via the flywheel. Hence why you still have drive.

 

[Bob dale]

The system doesn’t work very well with a leaky tank cap, the hydrostatic trans works separately to the lift/ tip and steer, although it uses the same oil! Try taking the hoses off the steering ram and blanking them off, the steering wheel will now only turn a small way each way. If it turns all the way round still, the relief valve is open to tank, try tipping!

 

[Bob dale]

Hi I’ve done what you said blank the 2 hoses to the steering ram and the steering still hard and can’t turn it much I’ve put pressure on the steering and it tips and goes up slow but the engine was under load and it started chugging then stopped now it won’t start thanks bob

 

[Mick-the-fitter]

Sounds like the priority valve is stuck giving all oil to steering!

 

[Mick-the-fitter]

Put your hoses back on the steering ram, there will be pressure in the hoses now, we’re you revving the engine when tipping?

 

[Bob dale]

Sounds like the priority valve is stuck giving all oil to steering!

Hi I’ve got it to go right up and tip but you have to keep turning the steering but as soon as yo let go of the steering it comes down on its own when you turn the steering it jumps bit at a time but you still can’t turn it easy thanks bob

 

[Bob dale]

On a HD1000, you'll find the pump that drives the steering and tip hydraulics is bolted to the engine near the fuel injection pump. Chances are that is worn and changing the oil has caused it to air lock. When they are worn they don't self bleed like they should. I'd check the suction lines for leaks (the big pipe into the pump) if no leaks are found try slackening the pressure pipe and crank it over and let it run till oil appears at the fitting. This should give the pump enough to prime the rest of the system. If the hydraulics are still weak or get worse when they are warm. The pump will likely need replacing. Can't say I have had many relief valve issues but I suppose there is a small chance that could be the case. But you'd likely have other symptoms... The tank filter is a return filter for the main hydraulics I'd get this replaced at the soonest available opportunity. The other filter is under the footplate near the steering column.

As others have stated above, this pump is independent of the main drive pump bolted to the rear of the engine and driven via the flywheel. Hence why you still have drive.

Hi thanks for info I did crack the not on the big pipe and nothing came out it was just a fine spit of oil and when you slowly tighten it spits air and oil as if the system is full of air thanks bob

 

[Bob dale]

Don’t write it off just yet…..

I’m not going to pretend to know your machine inside out, I don’t, others might though so don’t give up hope.

But from where I’m sitting…..
Is there any way you can do a hydraulic pressure test on the pump? From what you’ve said previously, it’s full of oil? Correct?
I’m guessing the hydraulic pump setup is very similar to a Terex roller? Maybe take a picture for us all to see, if you can? Is so, then the travel pump is an entirely separate pump to the tip and steer pump/pumps? My first thought, aside from a knackered pump and/or any electrical issues, is possibly the tip/steer pump is struggling to get oil. Possibly the pipe that feeds the pump/pumps is blocked with debris or possibly collapsed inside and causing the pump to be starved of oil? That would be my first point of inspection with basic tools and no knowledge.

Thanks for info it does sound like oil starved it went wrong last year lost drive but it was electrics then I thought I was doing good by changing hydraulic oil then everything went wrong I can’t see any damage pipes thanks bob

 

[Bob dale]

So it goes forward and backwards.

It steers.

Does high lift work? Without doing anything else

Yes it goes forward and backwards the steering is like rock to turn it fights you back on the steering wheel and it won’t lift or tip only to day by turning the steering wheel you can get it to tip and lift but as soon as you let steering wheel go it comes down thanks bob

 

[Bob dale]

Put your hoses back on the steering ram, there will be pressure in the hoses now, we’re you revving the engine when tipping?

Hi there was no pressure when I put the hoses back on and no did not rev it as it choked up and engine cut out it took over half hour to get it running again thanks bob

 

[Mick-the-fitter]

Ok Bob, thanks for the photos, the tank photo shows the top half of the filter, but also these two hoses are feed and return for the hydrostatic transmission, there won’t be a lot coming out of them unless driving, the hydraulic pump is supplied from the bottom of the tank, out sounds like you have a priority valve issue, when you turn to left or right and hold the steering wheel, you should be able to tip? By dead ending the ram hoses we have eliminated the steering ram leaking past it’s seals internally!

 

[jd6820]

Hi thanks for info I did crack the not on the big pipe and nothing came out it was just a fine spit of oil and when you slowly tighten it spits air and oil as if the system is full of air thanks bob

Maybe worth undoing the pipe further, it should come out of the pipe at a fair rate! Certainly fast enough to make you panic. If this isn't happening you have a restriction on the inlet side of the pump or as I originally suspected a knackered pump. It's an ally gear pump and I've changed a few... Can you take a picture of the pipe you are slackening?

The reason I suggest starting here as any checks further upstream are voided if the pump is at fault, starting at the pump which isn't bad to reach is a start. I'd have put a flow meter on it myself and checked flow at 2500psi, but as a DIY'er I'm guessing this isn't really an option?

 

[Mick-the-fitter]

Maybe worth undoing the pipe further, it should come out of the pipe at a fair rate! Certainly fast enough to make you panic. If this isn't happening you have a restriction on the inlet side of the pump or as I originally suspected a knackered pump. It's an ally gear pump and I've changed a few... Can you take a picture of the pipe you are slackening?

The reason I suggest starting here as any checks further upstream are voided if the pump is at fault, starting at the pump which isn't bad to reach is a start. I'd have put a flow meter on it myself and checked flow at 2500psi, but as a DIY'er I'm guessing this isn't really an option?

What was the flow at 2500 psi? But if pump not working! What would the engine be struggling with?

 

[Bob dale]

What was the flow at 2500 psi? But if pump not working! What would the engine be struggling with?

The pump on the side that you say runs steering and lift is hard to get to and see I’m not sure what pipe I need to take of to see if I’ve got pressure I might have to do one at a time and then start the engine each time to see which hose is pumping out of oil . I must say that even the forward and reverse will only drive when it’s warm thanks bob