Hydraulic spool valve not doing what it should

[m_c]

Did you drill and tap the cover for the HPCO adapter?
If so, that's where I would look first.
If the adapter isn't perfectly aligned with the bore, then there is every chance that is what's leaking under pressure.

 

[julianthegypsy]

It's been many years, so I could be completely wrong, but I *think * those are adjusters, used for setting the spool to actuate a single or double acting ram, by altering the length of travel of the spool.

 

[chrismac]

Did you drill and tap the cover for the HPCO adapter?
If so, that's where I would look first.
If the adapter isn't perfectly aligned with the bore, then there is every chance that is what's leaking under pressure.

Yes it was drilled on a mill, the hole on the inside was picked up, then the cover was turned over and drilled, never had reamer the correct size but had one slightly smaller, used it and took, oh its been a few weeks a 0.2 or 0.3mm off the small OD and screwed it in with the O-ring tighter than it would be originally, the adaptor was aligned spot on to the hole so hopefully thats not the issue. But maybe I should unscrew it and make sure the o-ring is intact.

And after re-reading your earlier post, I attached the gauge to the loader spool in not the loader spool out as you said, I'll do that some night and see if there is any difference there, with out being dumped to tank, I wont get any pressure reading will I? I dont get any reading on the gauge on the spool in unless I max out the travel on the rams, or on the HPCO until the mower was on the back.

 

[chrismac]

View attachment 503473
It's been many years, so I could be completely wrong, but I *think * those are adjusters, used for setting the spool to actuate a single or double acting ram, by altering the length of travel of the spool.

It would seem that if they are unscrewed, the rams act like single acting, probably for single acting rams, then when I screwed them in I was pumping in both direction.

 

[chrismac]

I disconnected the return line to the tank, the 3 pt linkage works as it should now, strangely the loader also seems to work fine..... cant make any sense of that as I was expecting the loader to be fixed in position with the return disconnected, it would be good to get to the bottom if the issue, but I can leave it plumbed in and disconnect the return when I am using the 3pt linkage as its on a quick release coupling anyway.

So this is implying I have a leak somewhere but no idea where that could be. Cant think its the O-ring on the adaptor unless its destroyed its self on the way in which will be worth a check.

 

[julianthegypsy]

It would seem that if they are unscrewed, the rams act like single acting, probably for single acting rams, then when I screwed them in I was pumping in both direction.

That's exactly what I expected, and for exactly the reason you describe.

 

[chrismac]

Did you drill and tap the cover for the HPCO adapter?
If so, that's where I would look first.
If the adapter isn't perfectly aligned with the bore, then there is every chance that is what's leaking under pressure.

you were spot on, the o-ring was nipped on assembly and thats where the leak path was, thanks for your help and pointing this out.