The Classic Machinery Network

Hi all,
New to this forum so all help much appreciated !

I have a 1992 Pel-Job LS502 - 5 ton excavator that has become a little tired.

I am using it around my place to move earth (stoney welsh mountain - few hundred ton left over a few years)............

I have plenty left to do and would like some opinions as to should I spend money
on what I have or try and scrape the pennies together and get a newer machine - that I cannot afford !

The machine seems to be down on power and gets very hot after only half an hour of work at which point
any real load causes the engine to rev down to almost stalling............

Would anyone have any advice to offer ? Anyone know a good pump overhaul company that would be able to
have a go at it ?

Will there be any real benefit in an engine swap ?

I am in Bridgend, South Wales - anyone fancy a hobble ?

Any input on the subject most welcome...............

Jon.

Hi Jon, can you please give us a bit more detail of the machines ailments?
For example has the basics been checked; airfilter, coolant level, tophose to radiator becomes hot when it overheats (indicates that the thermostat has opened correctly), clean radiator, does not blow the coolant out of the radiator or header tank?
I would not remotely consider an engine change until the problem was correctly diagnosed.
Daft as it may seam even the altitude at which the machine is being operated can effect its performance!
Just a few ideas here but some more detail may help myself and others on here to help you.

Jeremy

More detail :

radiator full, does not use water as such............Air filter clean...........actually without thermostat when I bought it, still without...............

Only a few hundred feet above sea level............. Does not seem like a head gasket issue.........seems more pump/ hydraulic related.........

really down on power - as if the engine is being starved of fuel - fuel filter fine though.................

Thanks all, Jon.

Do the bigger peljobs have the filter inside the electric fuel pump like the smaller ones did as this was often missed,what sort of flow are you getting from the diesel tank ,tanks venting ok

cheers graham

The fuel pump is Mechanical - cam shaft driven I think...........

Flow from tank seems fine - idles really well and revs really freely on the pump...........

So Jon when the problem occurs and the engine power is dragged down is this on all of the machines functions?
When the power is dragged down does the engine splutter and misfire or the power simply dies off?
Does it smoke when the power drops off?
I can only think of the following areas that could be a possible problem; firstly check all of the engines air intake system not just the airfilter, temporarily disconnect it from the inlet manifold and see if this cures the problem (once you've checked that it rules out air starvation), secondly make sure that the fuel system is not sucking any air in (although I do not suspect that this is the issue here), thirdly check that the fuel lift pump is okay it may have a split diaphragm and/or a blocked filter gauze in it (some pumps have a filter built into the top of them).
If you check the above is all okay then I am wondering if there is a hydraulic problem thats overloading the engine and dragging it down?
Hope these ideas help I would still double check the fuel lift pump as this may well be the problem.

Jeremy

Thanks for the input jeremy - only thing I have not checked is the fuel lift pump internal gauze filter - will have a look this morning............

Power seems to just die off under load - I have to back off tracking, lifting, digging action what ever to allow the revs to climb back up..............

I am having to run the engine at full revs to get anything at all - all the time !

Jon.

If your hydraulics are poor,first check,oil level,filter / strainer.Does the pump body get very hot ? Pump may need overhaul. Is it fitted with an oil cooler?
Engine getting hot, radiator blocked,fan belt slack.thermostat stuck. ( just remove it and recheck ) oil level check.Bubbles in the coolant filler ( head gasket gone)
Loss of power on engine,Air intake filter blocked,low fuel pressure,filters and strainer blocked,lift pump failed.
I live 10 miles from you. "Hydrobrake " at Bridgend industrial estate are good for hydraulic supplies. Sound like your hydraulic pump is worn out if the engine is reving OK.Perhaps the hydraulic drive coupling is at fault between pump and engine ? You need to check your pressures on the hydraulics.That would eliminate that fault. Then check that the engine is firing on all cylinders by slackening off the injector pipes one at a time.If you get one injector not working that would reduce your power output,and if its dribbling would cause engine damage.Is the exhaust chucking out black smoke under load ? This is caused by overfueling from the pump.Fuel delivery fault or hydraulic pump on the way out.
Martyn

Hi Martin- many thanks - working through as we speak !

Will post results later - pump does get very hot- has a separate cooler rad - I have just added an electric rad fan to that to help - has made a BIT
of a difference but seems as if the machine is working it's nuts off to do low load stuff..............Jon.

If you feel like having a nosey you're more than welcome - I've got cold beers in the fridge : )

Hi jon,
I'm not far from you either.
I have a few ideas, but first could you tell me?
Does the engine rev OK off load and are the hydraulics up to speed off load, are the hydraulics noisy, do they whine or scream?
Fred