Oil leak from "main gallery access port" in New Holland 1725

[jonathan starr]

I had oil spewing from this port the instant I started up my tractor. I'd been snowblowing on fresh snow the day before, so I know I hadn't dripped so much as a drop yesterday.

The manual says it's the "main gallery access port" and nothing else about it. I looked in the engine parts manual and it doesn't have a part listed for it. It's 1/4" diameter. Of course it's tucked behind the hydraulic pump without an inch of clearance, and several lines and hoses, and is barely visible, let alone reachable. I probed the opening with a wire and there doesn't seem to be any threads, or even a counter bore for a welsh plug. There may be a lip fairly deep into the bore, but at the angle I'm probing I could be hitting something else, or just sticking on the bend of the wire.

I'm wondering if anyone knows if this is indeed a welsh plug or something else. Also, if it's a plug, I'd like to try setting it without removing everything to get to it (my mechanic says it's at least a ten hour job to get everything out of the way and back together) Is it futile to try to set a plug at a slight angle? I've never set one, this isn't my ideal first attempt, but I'll give it a try if it means saving all those hours.

The engine I'm showing is obviously not mine--but it's the same model. It's impossible to get a good photo of the port on mine with everything in the way. Thanks for any advice.

 

[RjCorazza]

I also checked out the parts diagram. Unfortunately, I have no advice on the plug... But are you absolutely certain the oil isn't coming from the pressure relief valve?

 

[TractorTech]

Looking at that parts book (pics here) and same block on other models, it's likely a plug listed, #6 - 10.4mm or #7 - 6.6mm.
Another model show an 1/8" npt plug closer to where you are showing, although you indicated it doesn't seem to be threaded.

Is the hydraulic pump tucked behind a frame rail or loader mount? 10 hours should allow you to split and put together that tractor. Just trying to understand where your mechanic came up with the hours

 

[jonathan starr]

I also checked out the parts diagram. Unfortunately, I have no advice on the plug... But are you absolutely certain the oil isn't coming from the pressure relief valve?

Yes, we got a visual on it when cranking it over.

 

[jonathan starr]

Looking at that parts book (pics here) and same block on other models, it's likely a plug listed, #6 - 10.4mm or #7 - 6.6mm.
Another model show an 1/8" npt plug closer to where you are showing, although you indicated it doesn't seem to be threaded.

Is the hydraulic pump tucked behind a frame rail or loader mount? 10 hours should allow you to split and put together that tractor. Just trying to understand where your mechanic came up with the hours

No, it's easy to get to. I've been trying to understand it as well. He's not a full time tractor mechanic, but he does house calls. I think he was being extremely conservative.

 

[TractorTech]

10 hours, conservative?
6.6 mm plug is close to 1/4".

 

[MTGreen]

It sure looks like a plug in the pic -welsh/welch/freeze plug or otherwise. What else could it be? Sometimes these are added to allow a machining operation on the casting to take place through the hole during manufacturing and are never touched again even on rebuild.

It occurs to me if you have or can make a reasonably parallel surface to press against on the inner surface of the hydraulic pump; you may be able to sneak the equivalent of a machinist jack in there to press the new plug in straight. -if you don't have access to machine tools to make the exact tool for the job you might be able to get by with a fillister head screw with a jamb nut and a rod/extension/coupling nut to press against:

 

[jonathan starr]

It sure looks like a plug in the pic -welsh/welch/freeze plug or otherwise. What else could it be? Sometimes these are added to allow a machining operation on the casting to take place through the hole during manufacturing and are never touched again even on rebuild.

It occurs to me if you have or can make a reasonably parallel surface to press against on the inner surface of the hydraulic pump; you may be able to sneak the equivalent of a machinist jack in there to press the new plug in straight. -if you don't have access to machine tools to make the exact tool for the job you might be able to get by with a fillister head screw with a jamb nut and a rod/extension/coupling nut to press against:

 

[jonathan starr]

Good ideas, I think I'll be giving one a try when I get a plug. Will report back!

 

[jonathan starr]

10 hours, conservative?
6.6 mm plug is close to 1/4".

Meaning, padding his time.

 

[ericm979]

It looks like its a slightly oversize cylinder thats driven into the bore. I have seen that in a few engines. Sometimes its a ball and the case is peened over to lock it in. You could make your own plug and seal it with a small amount of good case sealant like Dirko or Yamabond #4. One concern is that if its too long it may block a cross drilled gallery. The step may be there to prevent driving it too deep.

I'd be paranoid after a fix like that and try to rig up an oil pressure idiot light or gauge and watch it like a hawk.