B25V boom pressure issue.

[GlenM]

We have a Yanmar B25V mini digger which works absolutely fine, except that the boom ram will not hold pressure. It works fine with normal digging work but lifting anything heavy requires the lever to be held back constantly. Is it likely to be a ram seal issue?

 

[V8Druid]

We have a Yanmar B25V mini digger which works absolutely fine, except that the boom ram will not hold pressure. It works fine with normal digging work but lifting anything heavy requires the lever to be held back constantly. Is it likely to be a ram seal issue?

likely that or the piston is parting company with rod

 

[GlenM]

likely that or the piston is parting company with rod

It doesn't feel like anything that drastic. My other thought was an issue with the control valve for the boom. All other ram hydraulic pressures seem to be good.

 

[Monkeybusiness]

I’ve got a mate with a Yanmar that has a similar issue with the bucket ram (and also the dipper ram on occasion). It’s still under warranty but the dealer and Yanmar have both basically washed their hands of it and reckon it’s normal.
I’m afraid to say I wouldn’t touch a Yanmar with a barge-pole from what I’ve seen/heard…

 

[Shovelhands]

We have a Yanmar B25V mini digger which works absolutely fine, except that the boom ram will not hold pressure. It works fine with normal digging work but lifting anything heavy requires the lever to be held back constantly. Is it likely to be a ram seal issue?

Re-sealing the ram will likely be the cheapest and easiest thing to start with and you’d probably not want to got delving any further into expensive items until you were sure the ram was ok. So that where I‘d start personally.

 

[GlenM]

I’ve got a mate with a Yanmar that has a similar issue with the bucket ram (and also the dipper ram on occasion). It’s still under warranty but the dealer and Yanmar have both basically washed their hands of it and reckon it’s normal.
I’m afraid to say I wouldn’t touch a Yanmar with a barge-pole from what I’ve seen/heard…

This one is a 2005 model that I bought about 4 years ago. I had a 1992 Yanmar B27 before that, which was rather tired but just kept going and going. It fact it's still being used by the new owner now. Perhaps their quality has dropped on the newer machines.

 

[GazCro]

Is it not liking lifting heavy stuff or if you leave empty bucket in the air is it on the deck in under a minute. They are not a crane after all.

 

[Monkeybusiness]

This one is a 2005 model that I bought about 4 years ago. I had a 1992 Yanmar B27 before that, which was rather tired but just kept going and going. It fact it's still being used by the new owner now. Perhaps their quality has dropped on the newer machines.

There’s definitely an issue with his machine, which is essentially as-new. Yanmar and the dealer are basically hopeless - absolutely no backup to speak of.
The sad thing is he loves the digger in every other way - it drives really well and is a tidy package. Just a shame it’s let down by the human element!!!

 

[GazCro]

There’s definitely an issue with his machine, which is essentially as-new. Yanmar and the dealer are basically hopeless - absolutely no backup to speak of.
The sad thing is he loves the digger in every other way - it drives really well and is a tidy package. Just a shame it’s let down by the human element!!!

Sounds like a cavitation issue. Old 8015 had that jcb no interest in even having a look we just got used to it and worked around it. It was fine if you were just steady away but if you really started trying to fling it about you could get it to do it quite predictably. You just had to have wits about you when digging round services.

 

[CPS]

Id be aiming for the ram seals also. But just check that the little plungers in the joystick are all coming up fully also

 

[Canal Navvy]

Does it stay up if you lift the machine up on its bucket (like you would if you were working on the tracks) ?

 

[GlenM]

Id be aiming for the ram seals also. But just check that the little plungers in the joystick are all coming up fully also

Ok. Thanks. Is it easy to check the plungers?

 

[GlenM]

Does it stay up if you lift the machine up on its bucket (like you would if you were working on the tracks) ?

I haven't tried that recently. I guess if it doesn't stay up it proves that fluid is getting past the seals in the ram in both directions.

 

[GazCro]

I haven't tried that recently. I guess if it doesn't stay up it proves that fluid is getting past the seals in the ram in both directions.

Is it capable of holding its arm up with an empty bucket or a bucket of soil or is it struggling to hold a full dumpy bag up?

 

[CPS]

Ok. Thanks. Is it easy to check the plungers?

if you lift the rubber gator up that is around the base of the joystick you will see 4 domed shape plungers, check the front one is rising up full when you let go of the lever

 

[Mick-the-fitter]

Mark the 4 servo pipes under the lever, take them off move the boom pipes to the bucket and vice versa, does it still drop?

 

[GlenM]

Finally got round to looking at this yesterday. I left it up on it's blade and the bucket and it was still up in the air this morning. Does that completely rule out the ram seals? Will check the plungers next.

 

[V8Druid]

Finally got round to looking at this yesterday. I left it up on it's blade and the bucket and it was still up in the air this morning. Does that completely rule out the ram seals? Will check the plungers next.

well you have two methods of support there the blade and the main boom/dipper/bucket so one could be shot and t'other fine ... you need to try it one at a time - preferably the suspect item first

 

[Shovelhands]

well you have two methods of support there the blade and the main boom/dipper/bucket so one could be shot and t'other fine ... you need to try it one at a time - preferably the suspect item first

I know he hasn’t said so, but I assumed that he’d left it in the air with the blade at one end and the boom the other? So the entire weight of the machine is supported? If thats the case then it’s actually impressive that it stayed there in that position overnight.

 

[Mick-the-fitter]

Any external leaks? There were some O ring issues on the block back in the day! Warranty issue have a bag of them somewhere!