Hymac 370c hydraulic problems

[arrolman]

Hi all,

Not been on for a while due to work but have recently been using my hymac 370 to dig out and scrape a few tons of mud and rubble next to one of my sheds. The machine has always been slow and hydraulic pump has screeched a bit but as I was using it the other day the loader started to get very hard to lift, had to give maximum revs to get it to move at all. The pump is whining like hell as well. Steering was non existant unless I on idle and couldnt use the loader and turn the wheel at the same time. Today I pulled off the hydraulic filter that is under the cab, found it to have collapsed so replaced it and topped up oil. Started up and now getting no power to backactor side rams or the stabilisers. Loader wont move unless full revs and then will only move a few inches/stop/few inches/stop.

Now, I cant get the front hydraulic filter housing off, its solid. Need to get some heavier duty bars to put over the end of my shifter. Will hopefully get that off and changed on friday, I am also going to empty the hydraulic tank and give it a good clean. Question is, does it sounds likely the pump is on the way out? Any idea of a rough cost of refurb/replacement if so? I need it in the next couple of weeks to put drains in and dig out some new trackway so need it fixed ASAP if it is the pump , any ideas would be welcome. (All levers are in nuetral position, pump is slightly noisy when at idle)

Cheers,
Iain

[Jeremy Rowland]

Hi there it does sound like you hydraulic pump is knackered I have pm'd you at to where you can get it fixed.

Jeremy

[TullyveeryClassicJCB]

On my 370c the filter is behind the grill. Some 370c's allowed a hell of a lot of water to get into the tank. What condition is your oil like?

[arrolman]

That'll be the one I cant get off, in front of the radiator? Oil seems ok, going to empty the tank out fully so will be better able to see condition then. Jeremy, have sent you a reply

Cheers,
Iain

[FOWLER MAN]

Hi Ian,
I don't know the 370C. Is the filter you refer to a return line filter or on the suction side?
There must be a suction strainer/filter where the pump feed leaves the reservoir, either in the reservoir or somewhere on the suction line.
It is possible that a restricted flow through a collapsed /blocked suction strainer/filter would cause suction hoses feeding the pump to collapse too.
They may look OK but can collapse and block internally .
This would also cause the pump to scream and all the other problems you mentioned so check this out and change or clean all filters and strainers before thinking of spending your money on a pump.
Sounds like a restriction on the suction side of the pump to me.
Does the engine load up when you try to use the hydraulics?
Fred

[arrolman]

Hi Fred,

Front one will be suction, the one I cant get off at the moment. All the filters I have changed so far on the machine had either disentigrated or collapsed so would be a reasonable guess to believe it will be fubar. I only had half a tool box with me today and it wasnt enough to budge it. If I use the hydraulics on idle they will work slowly, as expected. Any revs causes pump to scream and minimal movement from either front or rear, it seems to me its been a gradual problem so im hoping something is collapsed/blocked, going to price up a recon on the pump just in case though

Cheers,
Iain

[essexpete]

Well the fact that the pump will just about work on idle but scream on revs would put my money on Fred's explanation. Not enough oil passing to pump causing it to scavenge and cavitate.

[topkit]

If you cannot physically get the filter off by and i would get a filter strap on it that should work like Fred and Pete have said it sounds like that is your problem.

[arrolman]

No chance of getting filter cover off with a strap, tried that as well, its totally solid. Ive got some plus gas and going to put a scaffold bar onto my shifter and see if that cracks it, theres hoses running underneath it meaning I cant get a socket onto it with a ratchet, nothings ever simple!!

Cheers,
Iain

[arrolman]

Just a quick update, managed to finally get the hydraulic filter off and changed, paper filter was mush. No water or heavy sediment in the housing which is a good sign. Now changed for new and all refitted, currently awaiting some dry weather to empty and clean out the hydraulic tank and bottom strainer. Will post up again once I have done and the outcome.

Cheers,
Iain