to rebuild or not rebuild hyd pump? JD310D

[Finca SDR]

Hi everyone!

So after working successfully for almost a whole week after the reverser issues were resolved, something else started making loud horrible clanking noise and I had to turn it off.

Mechanic dude was able to ascertain pretty quickly that the splined shaft driving the hydraulic pump was stripped and that's the source of the noise, no broken rods or seizing pistons so no worries there. Not a big problem to fix that part at least.

But... he disassembled the pump to get the axle out and found some wear damage in there. Gears are visibly worn (they look clean and pristine to me but he says there should be no visible gaps in between the teeth), and there are scratches on these little plates he's calling mirrors (Spanish translated) and inside the mid-body housing, if you want to call it that. He says it should really be rebuilt before we reassemble the thing cuz it's gonna break eventually and possibly take other parts with it (control valves).

... no biggie, only $300 worth of parts, no extra labor... except it turns out to be over $900 for the parts. Prices always seem to go up since the last time you did something. So dude says we'll just put it back together cuz that's too much to spend at this stage, but I will have problems at some point. I know he's honest.

Anyone have any insight on half -worn hydraulic pumps? It was one of the only systems that was working properly on the machine. Anyone ever heard of lowering the pressure to abuse it less.?

Thanks for reading and any advice, I know I'm long winded

 

[Former Wrench]

You might be further ahead to replace the pump. I would guess that if the pump gears are worn, so is the inside of the housing. Either that or reassemble it and roll the dice.

 

[Finca SDR]

Thanks, thats what the dude here says... but due to extraneou$ factor$, probably just gonna reassemble it and hope it doesn't take anything else with it when it fails

 

[heymccall]

If this a gear pump, it won't fail catastrophically. It will just slowly lessen in performance over time.

 

[Finca SDR]

Thanks heymccall, that's good news, thanks. Do you think it could it lose little pieces that destroy other things?

 

[Steve the mechanic]

Buy a new pump and main relief valve. The hydraulic pump is the heart of the machine. The only thing a worn out pump does is put air and heat into your system, taking out seals and creating leaks. What you spend now will save you in down time, which cost a lot more than the parts.

 

[Finca SDR]

Hola Steve,

Yeah, you're probably right but the thing's been put back together and working for a while now. The nature of this old machine is that I don't really get to fix things "preventive" style that much. It pretty much gets fixed as it breaks for real because every $1000 repair will be followed by another one pretty soon. Can only do the ones that keep me from working right now and not everything I know is a problem. Eventually I hope that it'll be refurbished enough to be in decent reliable shape.

That's totally correct about the down time. The repairs aren't expensive. It's telling people you can't do the job that's expensive.

 

[Tinkerer]

If you are that busy, have you thought about buying another T/L/B ?
By that I mean have two available at all times.

 

[Finca SDR]

Hola Tinkerer,

Yes, that thought had most definitely crossed my mind. Just gotta get 15-20k in order to buy some other old piece. I think it'd be better to have two real old pieces instead of one slightly newer piece that costs twice as much. A ten year old backhoe can have repairs just as expensive as a twenty year old backhoe, I've noticed. Was originally thinking that when I get some money together again I'll get a dump truck. but in five years of dirt moving i've filled dump trucks two or three times. What would really be great is a spare backhoe...