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Thread: Lamborghini 90 Hydraulics Fault

  1. #1
    barley09
    Guest

    Lamborghini 90 Hydraulics Fault

    Hi Folks,

    Our old 874-90 loader tractor (1994, 40 speed box) has had developed a fault following some hard work loading bales last week.

    The splitter now stops working and 4wd engaged light comes on (only at engine idle) after a period of hard work - heat related I am guessing - solenoid, drop in oil pressure perhaps?

    Secondly the power steering will simultaneosly become very heavy unless engine is revved up, some vibration through steering wheel and a strange grumbling noise, again this only occurs after a period of hard work - orbital unit or maybe pump again?

    Despite these faults linkage, loader etc all continue to work as per usual.

    Any ideas on likely causes, maybe testing the two pumps or other appropriate checks? Would it be worth trying a filter and oil change first?

    Thanks for looking.

  2. #2
    leone75
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    On these it is most likely the pump is drawing air or cavitating and may need the power steering filter changed . The filter on these is probably above the back axle . Worst case it could be a pump , there is a small pipe with jubilee clips on the filter could be the problem .

    Leone75

  3. #3
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Thanks leone, I will check that hose, the power steering filter is above the lift mechanism on these models.

    I Will change the filter anyway but am I right in thinking that a blocked filter may well show improved performance once the oil gets hotter and so thinner?

    Any thoughts re the splitter and 4wd? Is this also served by the power steering pump or at least through this same filter, if its the same as an Antares 100 we had before there are also a pair of hydraulic filters under the transmission? We have only put 200 hours on this old girl since purchase so havent had a good look through as yet.

    Cheers

  4. #4
    Pryderi
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    4WD, diff, pto and powerspeed is feed from steering pump. Steering pump takes it feed from hyd top cover which the hydraulic pump keeps full. First just remove filler plug with engine running to check that hyd top is actually kept full. It wont over flow but you should see the oil couple inches from top.

    As mentioned change steering filter (above L/H trumpet, take the two jubilee clips off slide pipe to one side and remove the two m8 nuts to remove whole unit to replace filter) with filter off check the rubber hose and o ring on housing very carefully.

    If all this fails you could pressure test pump but actually changing it is not a very big job as it's on outside of tractor behind fuel tank. Could change em at one time in hour and a half!!!!

  5. #5
    marco
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    If you've only just got it, i'd suggest the previous owner thought something was up and sold her. Also previous owner probably didn't change the filters.

    I'd drop a bit of backend oil and see what it looks like. If it looks like it hasn't been changed in a while, drop oil as well as doing filters.

  6. #6
    agrotron 150.7
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Quote Originally Posted by barley09 View Post
    Thanks leone, I will check that hose, the power steering filter is above the lift mechanism on these models.

    I Will change the filter anyway but am I right in thinking that a blocked filter may well show improved performance once the oil gets hotter and so thinner?

    Any thoughts re the splitter and 4wd? Is this also served by the power steering pump or at least through this same filter, if its the same as an Antares 100 we had before there are also a pair of hydraulic filters under the transmission? We have only put 200 hours on this old girl since purchase so havent had a good look through as yet.

    Cheers
    I Think power steering pump supplies 4wd system etc yea try filter but most possible pump and ther is also a pump coupler that joins the two pumps togethr in side worth a check if change pump, the metal pipes are oring sealed on flanges and rubber pipes can split an draw air but not leak oil, the noise you hear can also be the steering silencer but i wouldnt worry about that

  7. #7
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Thanks for the input Pryderi, Agrotron and Marco, will have a look at all that over the next couple of days!

    We only got it as a spare tractor and its the first time we've really given it some heavy use for a prolonged period. Lovely newish loader and otherwise tidy and up together so dont begrudge a few pounds if needs be! Will keep you posted. Cheers

  8. #8
    TP
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Make sure there's not too much oil in the backend I've seen several similar Same 90's do all sorts of strange thinks when folk who are best kept in the parlour have seen fit to add an extra drum of oil to the backend,to be fair depending on what brand of oil you use it can be easy to interpret the sight glass as empty when it's full and beyond.Too much oil makes the steering and everything else go loopy.Your symptoms do sound like a worn pump though.

  9. #9
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Right.... replaced pump with a new aftermarket one, all new hydraulic filters and oil.

    Light use here and there no problem, power steering noticeably better!

    First day of hard work today, loading muck, 5 mile road run with trailer.... and we are back to original problems.

    Have now noticed that during the problems the 4wd light is flicking on and off when I try to use the splitter and she appears to be in 4wd all the time. (Light goes on and off with switch as it should).

    Aside from the 4wd now being constantly engaged all is well until oil is got hot as have used for an hour or so here and there without an issue.

    Any further idea's folks?

    Cheers

  10. #10
    TP
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Brakes gone and blocked filters with filings again?Only way to be sure is to pull off the trumpet housings and check the discs.The early lambo's used a lower grade disc than the later Same tractors and it does fail,changed a few myself.I think there was a filter blocked warning light but the switch may be faulty or the bulb blown in the dash or italian wiring strikes again meaning the light doesn't work.If the brakes go it manifests itself as all manner of hydraulic problems.I did one many years ago (874-90t) that got filings into the orbital unit and the steering went bananas.Unfortunately when the brakes go it takes out either a piston or a diff bearing carrier housing which isn't cheap though you might get one from a breaker.If you are doing the brakes be sure to change the piston seals and test that you haven't nipped one before re-assembling.The brakes are a pig to bleed without a pedal operative as the ATF is so viscous. Don't use car brake fluid in the system.

  11. #11
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    ummm brakes are very good in terms of operation and did have a quick look at drained oil and filters - have seen a lot worse, but appreciate what you are saying. Would this particular problem / cause be exacerbated by heat as described though?

    No sign of that warning light coming on either but again I know what you mean re electrics on these!

  12. #12
    TP
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    At some point the brakes just go they don't last forever,stopping power will still be good with a slight growl if you are good at listening for that sort of thing.Once they go metal to metal there's metal filings and sludge big time.If you take out the suction pipe for the filters you might see the filings.If you turn off the 4 wheel braking under the rhs front of the cab it puts alot more strain on the back brakes and shortens their life dramatically.Seen a few folk buy a machine with the front brakes turned off and never knew to how to turn them on until the back brakes went. If you short out the switches on the filters to the chassis the warning lights should come on if the wiring/bulbs are good.

  13. #13
    Pryderi
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    The two hydraulic filters behind fuel tank would block first before the steering filter if brakes are gone. Check pressure at spool coupling first, does said tractor tip a trailer? Is PTO working ok? 4wd is not pack operated but by an external hydraulic cylinder. Unless it's a very early one( pre powerspeed) the 4wd light is activated by a switch on the actual linkage behind fuel tank and not triggered by the switch in the cab.

  14. #14
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Have just cut up the old filters and all three look ok, some 'grey matter' in the base but nothing unusual IMHO.

    Tipped a heavily loaded twin ram marshall trailer multiple times yesterday as well as loading with an MX100 loader. PTO also fine.

    I really am leaning towards heat being the cause, factoring in the 4wd being 'stuck' would this maybe indicate a heat related blockage or bypass in the little valve block on the right where the solenoids sit?

    Alternatively what about a heat related bypass in orbital unit, this could in my mind cause issues with steering and then the 4wd and powerspeed units would be affected as they are down stream in the system?

    Do you think a 10 mile round trip at 40k in 4wd (didn't know it was stuck until my return) has generated the excessive heat to cause this reccurence yesterday?

    Started tractor this morning and all normal again, but is of course cool!

    Thanks for your continued thoughts!

  15. #15
    Pryderi
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Runing in 4wd is only really going to sap up power and accelerate tyre wear!!! Now if you were only loosing the splitter and engaging 4wd you'd be looking at a problem with the low pressure cuircit (18bar) but as you'r also getting heavy steering there is obviously a pump pressure problem.

    As you may know the hydraulic pump returns oil to the hydraulic top cover which acts as reservoir for the steering pump. Next time you get the tractor hot and the problem returns take off the top cover filler plug with engine running, the oil should be up to about two inches from the top. If the level is ok and you've replaced pump already then start with basics on the suction side. Check the small piece of hose and the o ring seal between filter housing and top cover. Maybe just maybe pump is sucking air and cavitating when hot?

  16. #16
    Cowabunga
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    There is a hydraulic damper in the steering circuit. My guess is that this has failed and needs replacing.

  17. #17
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Will have a look at o-rings and oil levels etc tomorrow Pryderi - always a good call to double check the basics before moving on again!

    Assuming the o-rings etc are ok and following Cowabunga's lead....

    From the diagram I have and google translate it seems that there is an both an 'over pressure' and 'anti cavitation' valve in the steering distributor unit, are either of these what you mean by the 'hydraulic damper' Cowabunga? If so are they adjustable / repairable (sauer danfoss) or shall I just order a replacement unit? If not any idea where the potentially offending article lives?

    Cheers

  18. #18
    Cowabunga
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Quote Originally Posted by barley09 View Post
    Will have a look at o-rings and oil levels etc tomorrow Pryderi - always a good call to double check the basics before moving on again!

    Assuming the o-rings etc are ok and following Cowabunga's lead....

    From the diagram I have and google translate it seems that there is an both an 'over pressure' and 'anti cavitation' valve in the steering distributor unit, are either of these what you mean by the 'hydraulic damper' Cowabunga? If so are they adjustable / repairable (sauer danfoss) or shall I just order a replacement unit? If not any idea where the potentially offending article lives?

    Cheers
    It is what they call the anti-cavitation valve. Don't know where it lives, but if you follow the pipes it should be fairly obvious. Don't believe that it is a serviceable item and it will need replacing. All assuming that this is the offending article, which I strongly suspect it to be.

  19. #19
    Pryderi
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    There will be a resinator unit about 6 inches away from the pump on the output pipe. A square block with two tube like pieces screwed onto it pointing downwards. One will be longer than the other. They are in essence just empty tubes. All these usually do is crack and leak oil and require either welding the crack ( with arc for best result not mig), or as usually the case replace the threaded hole with a plug!!!

  20. #20
    TP
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Here is a link the schematic for the hydraulic circuit for an 874-90T from the workshop manual.Hope it helps,the suggestion about a crack letting air in is worth investigating.Some grease or silicon over the suspect area should stop any air getting in to prove it one way or the other.


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  21. #21
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    Top class info as ever folks, cheers. Will let you know if and when there is a solution... there may be others in a similar boat in the future.

    Thanks again.

  22. #22
    Pryderi
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    [QUOTE=TP;1022901]Here is a link the schematic for the hydraulic circuit for an 874-90T from the workshop manual.Hope it helps,the suggestion about a crack letting air in is worth investigating.Some grease or silicon over the suspect area should stop any air getting in to prove it one way or the other.

    Now that is an old manual!! One of the firsts edition for the 774s and 874s. A real book not the ringbinder type?

  23. #23
    barley09
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    I reckon the copy i have on disc even pre-dates that one... no mention of powerspeed just 20x20, mini reduction boxes etc! Certainly lacked that annotated hydraulic diagram, just a brief description of the apparently different system on early 70 / 80 models.

  24. #24
    TP
    Guest

    Re: Lamborghini 90 Hydraulics Fault

    [QUOTE=Pryderi;1022975]
    Quote Originally Posted by TP View Post
    Here is a link the schematic for the hydraulic circuit for an 874-90T from the workshop manual.Hope it helps,the suggestion about a crack letting air in is worth investigating.Some grease or silicon over the suspect area should stop any air getting in to prove it one way or the other.

    Now that is an old manual!! One of the firsts edition for the 774s and 874s. A real book not the ringbinder type?
    Yes a genuine book and reasonably priced it was back then too.

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