Been working on hacked up Ascom 100 ton travel lift for last week. That one is “multiple offender delight”! The place is yacht repair shop, they use it to pull boats out of the water, or launch boats. Two biggest problems is: 1) One of the winches slower then the other four. And sometimes when you stop the winch you can’t restart it. 2) Weak travel, when this thing carries boat if It will go in to slitest depression it will stop. The story of machine is was bought used, imported from Italy, assembled here, and according to owner never worked right! It was hacked by a guy who died at very young age, because of complications resulting from his drug addiction. Never met the guy but after seeing his “work” I wouldn’t let him near any peice of equipment. I don’t know his qualifications ( I’m self taught my self ) but his workmanship is terrible, all the equipment he worked on is disassembled, components dropper on the ground under the weather not covered rusting and rotting! The owner has no paperwork for the machine at all, and said that Ascom will not provide information. What makes it worse is that machine have to be available to work. For example - one of the steering cylinders leaked, was taken off and hauled off for repair. Few hours later customer called that he will be at launch bay in couple of hours, it set the alarm! The repair place was called and told to assemble cylinder without repair and that pick up truck was sent to pick it up, because the fittings on the mach is DIN 3902 style and there is no way in hell we will find the plugs for hoses in two hours! So - the winches: Original Bonfiglioli is gone, only have couple of cellphone pictures shot by lift operator before they removed and hauled away for repair just to find out that it will be cost prohibitive! Don’t even know what kind of motors they had on it, from the picture I’ve seen could be either vane or gear motors. No information on those is available. Four military take offs was purchased and installed. No information on those, by the pictures on the internet looks like DP5883, 5882. Winches have two problems with it: one slower the other four, and because of that when they pick up the boat it starts to twist the hall and even scratches it wisth belts rubbing. After much testing, running, swapping the motors, we are 95% in to conclusion that gear ratio is wrong on this one, all it’s left to be 100% sure - is to fabricable the splined crank handle and count the turns and compare it to rest three of winches. Second - there’s strange problem with weird way they load up the engine to almost stalling speed. When you operated one it’s all good, two at the same time it loads u the worst, three - gets little easier, four is good. So first idea was that if original winches had vane motors which is high speed and high flow, but these DP have gerotors which is low flow that control valve puts out more flow tha new motors could not handle so much flow, but it didn’t sit well with being all fine when operating only one winch, then there’s list of sections on HAWE controll valve ( thank God we at least have that information and by the code of it the section puts out 60lpm which is 16 gpm and Char Lynn 104-2020 pass through 20 gpm in high speed and 40 gpm in low, that’s not it. So we started testing back pressure on return side of the motors: It shows progressive increasemant in back pressure in the control valve return gallery corresponding to: 55-130-195-263 psi with every winch added. The return to the back pressure (taken right at control valve return) is: 0-32-60-80 psi. There’s two theories left to confirm at this point: One - the pump is variable displacement piston, Brevini H1V in Delta P configuration. Interesting thing about it is that it being bent axis pump not required case drain but it has line for controller bypass oil ( the oil that gets behind piston through blow by), and it’s plumbed in to up stroke side of displacement controller, the other end of this line is plumbed in to main return line, and we have back pressure at that one starting with running two or more winches at same time. The theory is that back pressure upsets the hydraulic teeter-totter of LS system and cause it to upstroke the pump and put more flow than system can handle at that time. You might say that the loading up the engine is not consistent with this theory because at running four winches we get back to normal, but you got to remember that with adding more winches the system passing through more flow also, and it very well might be at four winches the out put flow of the run away pump finally meet the demand for it. I haven’t been able to confirm it yet by dropping that line straight to the tank because yesterday the lift was holding the boat all day to replace shaft seal. Another theory is - messed up LS controls on the pump it is confirmed that it is messed up mightily, but unknown at this point if it is a reason for winches loading up engine problem, more about that in the travel section. The travel problems: The travel when lift hits in to little depression in the gravel lot stops completely, do not load up the engine, and you have to rock it back and forth to get momentum to get out! Well! The most pressure I see on that machine is 2214psi, the pump destrocks it self at that point ( BTW forgot to mention that winches almost stalling the engine at 550-700 psi.) It is almost impossible to test Delta P LS system with dead heading motor or cylinder because you have to have the flow for pump to sense the pressure drop. All I can see at this point that all the sections of control valve i.e. winches, steering, belt sliders have port pressure reliefs in the sections, but travel section is not! That means it running system pressure relief ( main one), which is by name plate should be set at 350 bar or 5076 psi. And all we can get out of pump is 2214 psi. Right now I’m in process of developing the strategy how to reset the pressure compensator on the pump on the machine, with control valve 20 feet in the air, on the 2 feet wide beam, and without the possibility of dead heading something. I have couple of options involving either pump analizer at the ground level and rigging up the LS line using the load cell of analizer as both load and orifice the same time, or tapping needle valve in to a travel section of control valve and jump looping it back to return side. I haven’t picked one yet, what makes it all difficult is this machine having a fittings In DIN , BSPP, and even some GAZ standarts, finding DIN tee connectors around here is big PITA!!! The pump: was rebuild at some point, have new case and old backplate, whoever did rebuild didn’t bother to put nameplate back in the new plate or paint it. Then it was messed with horribly: minimal displacement screw ran all the way in ( goes to 2214 psi right away on the closed center system ) the threads on that screw mangled up and leaking oil despite having copper crush washers on both sides of the jam nut ( what was the reason to install washer between jam nut and the cap we will never know). The operator said that the guy who messed with the pump, did it so much that he actually stripped the threads on Delta P setting jam nut, I guess he thought that one was pressure relief. So the pump is out of whack, running partially as fixed displacement pump ( with minimum displacement screwed in al the way), partially as variable displacement (possibly loading up the engine too much when using the winches ) Another thing is strange is having motor spool ( the one that combines both sides to return in the center position) on steering, operator complained that he constantly have to realign the steering on this four wheel steer lift, he even made long hook shaped tool for the three shut off valve which mounted high up on the frame. That’s actually was done by manufacturer. You got to run motors spool on the motors equipped with counterbalance valves , and not having separate parking break line ( the design which uses shuttle valve to put pressure to the parking break piston when pressure applied to any of two ports), in fear that oil inside the hoses can heat up and set the parking break off! But why use it for steering or slide? I guess it was error made somewhere in ordering process between Ascom and HAWE. Anyways! This was a super long post! But if I’ll se enough interest I will post updates!
And I thought I had troubles....
Well that’s not all! There upgrades coming. Adding two more traction motors ( currently has only two ), adding three flow dividers and selector valve to provide sort off “ differential lock” in case of spin outs, replacing 108cc pump with something close to twice that displacement, replacing steering section in control valve with closed centered one, adding deverter valve to steering system to be able to lock rear wheels, doing zero turn, crabbing and sideways move, restoring all the electrical and electronic components for remote control.
So, the cliff notes version, a ship crane, bought overseas, no paperwork, disassembled poorly, reassembled by a drug addict with parts of unknown quality. Brother, I've had bad jobs and REALLY bad jobs. I don't think I've ever stepped in as large a pile as you have. Unfortunately , I haven't much to share. I did catch the bit on travel though and typically, travel motors have their own relief cartridges beside AB ports. So reliefs would not necessarily be in the valve. This brings us to testing the pump and valve. You could conceivably dead head travel from the control valve going out to motors. You should be able to set standby with your LS disconnected. Then hook up and demand travel against dead headed ports. Your valve bank should see main relief pressure at that point. At least this will give you 2 of 3 variables. Flow will still be a challenge as someone jacked with the max flow limiting screw. My concern is that the previous animal may have backed it out to the point where the screws drops off the edge of the swath plate and jammed it back in binding the plate. Something to look into for sure. Onto poor travel, are your motors in series or parallel? Typically, parallel with individual travel motors to allow for turning radius differential. One dud can spoil the works for all, it becomes the path of least resistance. Oh BTW, why is your case drain pressure so fu@<in high? Shouldn't be more than 1 maybe 1.5 bar. In my opinion. I'd be looking for high volume coming from one or all, additionally I'd check those hoses for flappers which could be obstructing return flow. Does your system have a case drain filter? Ever been changed if it's there? Good luck
Ooo! Don’t get me started on return and tank thing, the post will be as long just for that issue alone - the short version is: the original tank was rotten and they shop built the new one, and they had no idea what hydraulic tank is all about. High main return pressure can be explained by plugged return filter, but why in the hell I have 200 and something psi in the return gallery of the control valve? I guess I’ll find out soon, I hope! On the travel motors: those original, bent axis, have the valve block hanging on about 1-1/2’ of the steel pipes, the motors deeper inside the well, the valve block has only counterbalance valves and shuttle valve for releasing the parking break. About the pump: I’ve tried plugging travel ports but this is Delta P LS as soon as there’s no flow and no pressure drop because of no flow - pump just destrocks it self. But I gat couple of strategies how to go about it already, I’ll update you guys on it. That was kind a blog stile post, I don’t really have the questions I need to ask forum at this point, but any input will be greatly appreciated because the project is big, and I bound to miss something! I probably can use some opinion on resetting Delta P points and best way to go about it! That Italian pump kinda looks like copy of A78.
Update! Making a progress: First i didn’t like the high stand by, thought that minimal limit screw was screwed in all the way, so I plugged LS line and jumped the system pressure to LS port on controller, so there’s no pressure drop, and pump happily destrocked from 2214 to 250 psi. I decided not to mess with it ( although it’s a little low ) Then installed diagnostic tee and reconnected LS line - no LS pressure at all! Nada, null, zero! Started looking, remembered pump bypass solenoid, looked in the paperwork and saw that with code F its actually opens bypasses LS flow to return when not energized - it was unplugged - plugged it back in and now I have LS preessure! Told an operator to run winches and started adjusting the settings - surprisingly had results on PD the first time, but at that setting winches were barely creeping and drive didn’t move at all! Remembered about low pressure on everything, went to compensator - it was backed out all the way! Screwed it in - now I’m getting 4650 psi, drive actually kills the motor trying to climb over 4x4 but I have no pressure differential at all! Gauges just mirror copy each other, and things run can crappy, winches either barely creeping or load the engine up really bad! Out of like 30 times trying to adjust the PD maybe 3 or 4 I was able to screw the crew in, then start the engine, my system would run 2000ish and LS 800ish and I would be able to back the screw out to where system would fall to 1350 and LS would stay 800. But upon shutting engine down and restarting they will mirror each other again. Remembered reading about conversion in the manual: you can actually convert PSL connection plate ( for fixed displacement pump ) to PSV ( for variable displacement pump, if interested you can google PDF “HAWE PLS, PSM and PSV proportional valves and, go page 45 ) by moving and/or installing screw and carburetor jet, so I climbed up there and - bingo! Name plate saing PSV but dead head ( blocking) screw and absence of jet saying - was converted to PSL . And it finally got dark outside! So tomorrow will contact local dealer for that jet, move the screw, to right place and try again. If that will not help will try to adjust minimal displacement to highest stand by pressure listed and see what happens! So what we find out today - owner was right - this thing never did ran right! Wrong valve for wrong pump. The way it was molested - is they used LS setting screw to force over some partial flow and when it started loading up the engine - just backed the compensator screw out to lower the pressure. So basically ran variable displacement pump as a partial fixed displacement. That is all for today!
Are the winch motors plumed in series or parallel?
Parallel, each winch has its own section in proportional directional controll valve, five position spool - neutral, two precharge (return blocked ) and two working sections with trottling returns for the going down direction. The precharge is for induction of pressure to get parking breaks off.
Update: Was able to trace the inability of pump to regulate its flow to dirt inside of very small spool ( about 3 mm in diameter) and scratches on the spools polished surface. I think if spool scratched up, then bore scratched also and both leak. Scratches not very visible to the eye, but you can feel it with your nail, only on one side. Owner of the machine was able to magnify it with his phone (mine would not focus) to a very beautiful picture - but forgot to save it. That’s exactly the spool that sets the Delta P for LS. Spool was polished on the buffer and reinstalled, but leaking spool is a leaking spool! Even if it’s polished ( turd)! Regulator was reassembled and reinstalled, and ( happy medium ) was adjusted - because lift handles at least one boat a day. Today I think I will be having a field day trying to extort to DANA parts person what I need! Because there’s no name plate on the pump, no parts book, nothing! Lucky looks like they have only two configurations of these - one bolts directly to top of servo piston controller, the other hangs on short small diameter ( looks like break lines ) tubing, I hope that will narrow it down!