Bastard Scissor Lift

[Stroppymonkey]

morning. I have posted about this before. Hoping for some help/guidance with my 2008 upright x33rt scissor lift.
Low hours, everything works well on it. Bought with a slow /weak drive. Had someone look at it and sort a few issues. Found one wheel piped backwards and one set of brakes had been clearly recently worked on, so sounds like an attempt had been made. Brake circuit also stuck on.
An O-ring in the hydraulic cartridge in the block was found to be blown, and when replaced, all things working well and it came back to me.
Used it a bit, all fine then lost drive. Messed about trying to find genuine seals and spacers but they don’t seem to exist. Used generic seals and got drive back again. Used it a fair bit then parked up. Lost drive again! Finally got some genuine full cartridges from US. Fitted them yesterday and straight away blew the middle O Ring out.
clearly the issue I was treating as the fault is merely the symptom.
struggling to find a manual that matches the hydraulics on this machine .

2 x coil terminal's are not great so my next step is to clean and re crimp those.
I do not understand the function of the cartridges, not why the middle seals should be blowing .
I had assumed that the original cartridge/s were sticking or faulty but new ones had same fault some thing somewhere else is causing this issue.
it’s had new hyd filters and fluid. Everything else works perfect and when it chooses to drive its fine on both directions and steering, till the Oringd split and then it goes slower until it won’t drive.
Given that my day job is pipes solenoids and valves and pressures and fluid dynamics on water and fuel, it’s frustrating how ignorant I am with hydraulics!
I was very pleased with myself sourcing the new cartridges from Wisconsin. I fully expected that to sort this issue. I assume that they function as relief valves and need setting up with a gauge (sold mine!) but wouldn’t expect them to blow themselves apart due to incorrect setting? But I have already proven I know fuckall so who knows?

 

[V8Druid]

morning. I have posted about this before. Hoping for some help/guidance with my 2008 upright x33rt scissor lift.
Low hours, everything works well on it. Bought with a slow /weak drive. Had someone look at it and sort a few issues. Found one wheel piped backwards and one set of brakes had been clearly recently worked on, so sounds like an attempt had been made. Brake circuit also stuck on.
An O-ring in the hydraulic cartridge in the block was found to be blown, and when replaced, all things working well and it came back to me.
Used it a bit, all fine then lost drive. Messed about trying to find genuine seals and spacers but they don’t seem to exist. Used generic seals and got drive back again. Used it a fair bit then parked up. Lost drive again! Finally got some genuine full cartridges from US. Fitted them yesterday and straight away blew the middle O Ring out.
clearly the issue I was treating as the fault is merely the symptom.
struggling to find a manual that matches the hydraulics on this machine .

2 x coil terminal's are not great so my next step is to clean and re crimp those.
I do not understand the function of the cartridges, not why the middle seals should be blowing .
I had assumed that the original cartridge/s were sticking or faulty but new ones had same fault some thing somewhere else is causing this issue.
it’s had new hyd filters and fluid. Everything else works perfect and when it chooses to drive its fine on both directions and steering, till the Oringd split and then it goes slower until it won’t drive.
Given that my day job is pipes solenoids and valves and pressures and fluid dynamics on water and fuel, it’s frustrating how ignorant I am with hydraulics!
I was very pleased with myself sourcing the new cartridges from Wisconsin. I fully expected that to sort this issue. I assume that they function as relief valves and need setting up with a gauge (sold mine!) but wouldn’t expect them to blow themselves apart due to incorrect setting? But I have already proven I know fuckall so who knows?

first off - pic 3 - buy yourself some proper DIN plugs to go on the solenoids - cheap enough and no risk of shorts and LED shows voltage at plug
sadly no idea on the rest

https://www.ebay.co.uk/itm/407047376013?_skw=solenoid+DIN+plugs&itmmeta=01M3EKVNVVGVEDH6M14PX64B57&hash=item5ec5ea0c8d:g:yRUAAOSwUwJoGDog&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xD9L9CpnTp2g2l12694gS%2B8UN9pm2Ldzgp9BHijOTLRFNY903yawW2xpSQbncvAs13bGSXHTTziDOmWxVmcxjBtrISgSHtUApkqHZ08NdXUiVdI2Wp%2F0ccSBqmG%2FaM7ACqd5VjWtdJGjsRtb5r0jPBU5yo%2B6tpZ6T8lY3IZZ1dziYbkHdSazojFhhQhxaKk3jposXMnvrOAdiss1DfUZJ8ULAQiCmNo8Xo084TK1sUYFXDGDNrgrE3%2BTcI4aM7ti2S%2FJjgxsjF6nTadTe9KfQLjlV2THNgN%2Bf2RJD3OY81GJA%3D%3D%7Ctkp%3ABFBMnN7u05to

 

[jd6820]

morning. I have posted about this before. Hoping for some help/guidance with my 2008 upright x33rt scissor lift.
Low hours, everything works well on it. Bought with a slow /weak drive. Had someone look at it and sort a few issues. Found one wheel piped backwards and one set of brakes had been clearly recently worked on, so sounds like an attempt had been made. Brake circuit also stuck on.
An O-ring in the hydraulic cartridge in the block was found to be blown, and when replaced, all things working well and it came back to me.
Used it a bit, all fine then lost drive. Messed about trying to find genuine seals and spacers but they don’t seem to exist. Used generic seals and got drive back again. Used it a fair bit then parked up. Lost drive again! Finally got some genuine full cartridges from US. Fitted them yesterday and straight away blew the middle O Ring out.
clearly the issue I was treating as the fault is merely the symptom.
struggling to find a manual that matches the hydraulics on this machine .

2 x coil terminal's are not great so my next step is to clean and re crimp those.
I do not understand the function of the cartridges, not why the middle seals should be blowing .
I had assumed that the original cartridge/s were sticking or faulty but new ones had same fault some thing somewhere else is causing this issue.
it’s had new hyd filters and fluid. Everything else works perfect and when it chooses to drive its fine on both directions and steering, till the Oringd split and then it goes slower until it won’t drive.
Given that my day job is pipes solenoids and valves and pressures and fluid dynamics on water and fuel, it’s frustrating how ignorant I am with hydraulics!
I was very pleased with myself sourcing the new cartridges from Wisconsin. I fully expected that to sort this issue. I assume that they function as relief valves and need setting up with a gauge (sold mine!) but wouldn’t expect them to blow themselves apart due to incorrect setting? But I have already proven I know fuckall so who knows?

Those valves are counterbalance valves and they basically load hold the motors to prevent freewheeling. They will need to be set correctly (maybe come factory set) but given they drive okay maybe they are set correctly. Either a poor finish in the bore or an overpressure situation is blowing the seals...

Edit: I'd be checking for sharp edges when installing the valves, the o-rings are maybe being damaged during install?

 

[Stroppymonkey]

Those valves are counterbalance valves and they basically load hold the motors to prevent freewheeling. They will need to be set correctly (maybe come factory set) but given they drive okay maybe they are set correctly. Either a poor finish in the bore or an overpressure situation is blowing the seals...

Edit: I'd be checking for sharp edges when installing the valves, the o-rings are maybe being damaged during install?

Ta. I will need to get rid of the Hyd oil before I can inspect the orifice , but pretty sure Charles did that when it was with him. I will check.
If over pressure…. Where is it coming from? Something faulty somewhere else putting too much into that part of the system ?

 

[Stroppymonkey]

first off - pic 3 - buy yourself some proper DIN plugs to go on the solenoids - cheap enough and no risk of shorts and LED shows voltage at plug
sadly no idea on the rest

https://www.ebay.co.uk/itm/407047376013?_skw=solenoid+DIN+plugs&itmmeta=01M3EKVNVVGVEDH6M14PX64B57&hash=item5ec5ea0c8d:g:yRUAAOSwUwJoGDog&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xD9L9CpnTp2g2l12694gS%2B8UN9pm2Ldzgp9BHijOTLRFNY903yawW2xpSQbncvAs13bGSXHTTziDOmWxVmcxjBtrISgSHtUApkqHZ08NdXUiVdI2Wp%2F0ccSBqmG%2FaM7ACqd5VjWtdJGjsRtb5r0jPBU5yo%2B6tpZ6T8lY3IZZ1dziYbkHdSazojFhhQhxaKk3jposXMnvrOAdiss1DfUZJ8ULAQiCmNo8Xo084TK1sUYFXDGDNrgrE3%2BTcI4aM7ti2S%2FJjgxsjF6nTadTe9KfQLjlV2THNgN%2Bf2RJD3OY81GJA%3D%3D%7Ctkp%3ABFBMnN7u05to

That’s a great idea. Will do that

 

[Stroppymonkey]

first off - pic 3 - buy yourself some proper DIN plugs to go on the solenoids - cheap enough and no risk of shorts and LED shows voltage at plug
sadly no idea on the rest

https://www.ebay.co.uk/itm/407047376013?_skw=solenoid+DIN+plugs&itmmeta=01M3EKVNVVGVEDH6M14PX64B57&hash=item5ec5ea0c8d:g:yRUAAOSwUwJoGDog&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xD9L9CpnTp2g2l12694gS%2B8UN9pm2Ldzgp9BHijOTLRFNY903yawW2xpSQbncvAs13bGSXHTTziDOmWxVmcxjBtrISgSHtUApkqHZ08NdXUiVdI2Wp%2F0ccSBqmG%2FaM7ACqd5VjWtdJGjsRtb5r0jPBU5yo%2B6tpZ6T8lY3IZZ1dziYbkHdSazojFhhQhxaKk3jposXMnvrOAdiss1DfUZJ8ULAQiCmNo8Xo084TK1sUYFXDGDNrgrE3%2BTcI4aM7ti2S%2FJjgxsjF6nTadTe9KfQLjlV2THNgN%2Bf2RJD3OY81GJA%3D%3D%7Ctkp%3ABFBMnN7u05to

Thanks @V8Druid .
I have ordered new coils and led din plugs from RS. Interweb suggests that faulty coil/connections may cause over pressure on the pilot side.. but it may just be feeding me the answers it thinks I want.
I understand the valves a little more than I did, but not understanding the relationship between the 2. Will pop the stems out to take a peek at male and female parts. Will fit new coils and stems and then refit original hydraulic valves with double packed Orings as I know that’s worked before, then try again.

Still trying for a proper parts manual .

 

[V8Druid]

Thanks @V8Druid .
I have ordered new coils and led din plugs from RS. Interweb suggests that faulty coil/connections may cause over pressure on the pilot side.. but it may just be feeding me the answers it thinks I want.
I understand the valves a little more than I did, but not understanding the relationship between the 2. Will pop the stems out to take a peek at male and female parts. Will fit new coils and stems and then refit original hydraulic valves with double packed Orings as I know that’s worked before, then try again.

Still trying for a proper parts manual .

you could try backing the Main PRV off, clocking it and gradually increase the dump pressure at the MPRV until it's factory again (or maybe just a tad under)

 

[Stroppymonkey]

you could try backing the Main PRV off, clocking it and gradually increase the dump pressure at the MPRV until it's factory again (or maybe just a tad under)

I may need some more reading and YouTubing before I attempt that!
Email back from Tom at CherryPickerShop (on a Sunday!) helping with a with a couple of things and pointing out that mine although badged as a Upright X33RT it’s actually a Snorkel SR3370 which is why I have been struggling to find resources.
Going to need a pressure gauge (shouldn’t have sold my Digital one to @Mogman)
and some adaptors.

 

[bobthebuilder]

I may need some more reading and YouTubing before I attempt that!
Email back from Tom at CherryPickerShop (on a Sunday!) helping with a with a couple of things and pointing out that mine although badged as a Upright X33RT it’s actually a Snorkel SR3370 which is why I have been struggling to find resources.
Going to need a pressure gauge (shouldn’t have sold my Digital one to @Mogman)
and some adaptors.

Amazon do a reasonable cheap kit that will do the job

 

[Mogman]

I may need some more reading and YouTubing before I attempt that!
Email back from Tom at CherryPickerShop (on a Sunday!) helping with a with a couple of things and pointing out that mine although badged as a Upright X33RT it’s actually a Snorkel SR3370 which is why I have been struggling to find resources.
Going to need a pressure gauge (shouldn’t have sold my Digital one to @Mogman)
and some adaptors.

Always the business man
Will sell it back for twice the price

 

[Mick-the-fitter]

Thanks @V8Druid .
I have ordered new coils and led din plugs from RS. Interweb suggests that faulty coil/connections may cause over pressure on the pilot side.. but it may just be feeding me the answers it thinks I want.
I understand the valves a little more than I did, but not understanding the relationship between the 2. Will pop the stems out to take a peek at male and female parts. Will fit new coils and stems and then refit original hydraulic valves with double packed Orings as I know that’s worked before, then try again.

Still trying for a proper parts manual .

The cross section of the valve shows two backing rings, same as the white ring on the other valve, this would be important to align the prong with a centre land in the block!

 

[Stroppymonkey]

The cross section of the valve shows two backing rings, same as the white ring on the other valve, this would be important to align the prong with a centre land in the block!

Ah. The cross section image is a generic one explaining the function, rather than being specific.
I have the parts manual! Digital, but will get printed off as I prefer paper for this sort of thing.
Next step is to get the axles propped up so I can manually overide the freewheel to check nothing stuck on. Then I can see what drive it has with no resistance, it felt like 2 wheels were trying to pull and the others locked up.
New solenoids and plugs here so that’s a job in itself.
Test kit on the way, so then I can start seeing what pressures are where. Need to wrap my brain around the brakes function as that’s supposed to be piped in with the pilot valves..
Hopefully squeeze a go at it on Tuesday.

 

[Charlie]

Hats off to you. My bastard scissor lift won so i towed it out to rot in hell

 

[Stroppymonkey]

Hats off to you. My bastard scissor lift won so i towed it out to rot in hell

View attachment 85504

Probably what mine will look like in 5 years!

 

[DaveDCB]

Well if anything this thread has put me off buying one for our next job , hiring it is

 

[Giles]

Well if anything this thread has put me off buying one for our next job , hiring it is

Nothing more expensive than a cheap scissor lift

I bought 2 skyjack 28 ft rough terrains out of maltby accidentally came so cheap I should of known one was ok and sold thst for cost of both had to put the other back in though as you can spend weeks messing with them, afi will hire you one for £380 with delivery a week

 

[Stroppymonkey]

I agree!
I’m sure I will get to the bottom of it, it’s a tidy little machine and the right size to keep around for future shed maintenance on mine and Dads, and borderline towable . (Take the cage off and it would be legal I think)

 

[bobthebuilder]

Bought my scissors lift out of reading ,with a lohler ticket ,sky jack to about 30 ft ,new battery's and it works perfectly

 

[Stroppymonkey]

Had a poke at it this morning . Last time I used it, it was fine, then parked up for a bit. I put the new valves in and blew the seals straightaway. At the time I thought I noticed the back wheels dragging a bit. Needed to try it with wheels up in air. It’s too clever and won’t run wheels when legs down, so fooled it by jacking up, propping axles then retracting legs.

Messed about. Sprung operated brakes are always ON unless hydraulically released. Only on back wheels though.
Put new seals on the valves and refitted.
After @V8Druid suggestion I ordered up some LED DIN plugs for the solenoids.
some wiring butchery was required as plugs only allow single wires and was all 2 wired on each terminal.
Bought 2 new solenoid’s for Forward and Reverse drive as not dear and I am grasping at straws. The Brake OFF solenoid has very loose connections so I fitted a plug on there as well. I was suspicious of the brakes, so pulled solonoids off the drive then tried forward and reverse. NO LED on the Brake Solenoid which I think should be powered up when Forward or Reverse drive activate.
I have manually pumped up the brakes for now (only using on the flat ) and got on the ground and very happy to have drive!
Had a good afternoon’s work out of it until I ran it out of derv. Flipping idiot.

One leg wasn’t going down on Auto Level, only manual, but it seemed to fix itself.

Will get it jacked back up and will have another play. Need to get a test DIN coil plug made up on a switchable 12v supply to test the brake coil, and assuming it works as I expect then I need to chase the wiring back To find out why it’s not getting a signal. The live runs to a pair of relays that have been taped up, and look bodged in, next to an original relay that’s been bypassed, so someones had a fiddle with this historically.

 

[Lancs Lad]

Had a poke at it this morning . Last time I used it, it was fine, then parked up for a bit. I put the new valves in and blew the seals straightaway. At the time I thought I noticed the back wheels dragging a bit. Needed to try it with wheels up in air. It’s too clever and won’t run wheels when legs down, so fooled it by jacking up, propping axles then retracting legs.

Messed about. Sprung operated brakes are always ON unless hydraulically released. Only on back wheels though.
Put new seals on the valves and refitted.
After @V8Druid suggestion I ordered up some LED DIN plugs for the solenoids.
some wiring butchery was required as plugs only allow single wires and was all 2 wired on each terminal.
Bought 2 new solenoid’s for Forward and Reverse drive as not dear and I am grasping at straws. The Brake OFF solenoid has very loose connections so I fitted a plug on there as well. I was suspicious of the brakes, so pulled solonoids off the drive then tried forward and reverse. NO LED on the Brake Solenoid which I think should be powered up when Forward or Reverse drive activate.
I have manually pumped up the brakes for now (only using on the flat ) and got on the ground and very happy to have drive!
Had a good afternoon’s work out of it until I ran it out of derv. Flipping idiot.

One leg wasn’t going down on Auto Level, only manual, but it seemed to fix itself.

Will get it jacked back up and will have another play. Need to get a test DIN coil plug made up on a switchable 12v supply to test the brake coil, and assuming it works as I expect then I need to chase the wiring back To find out why it’s not getting a signal. The live runs to a pair of relays that have been taped up, and look bodged in, next to an original relay that’s been bypassed, so someones had a fiddle with this historically.

If nothing else you've done the hire industry a favour