Tracing '50 VAC leaks

Hi again all,

I'm trying to identify where the puddle of dark oil on the floor in the attached photo is coming from. From investigation, it looks like it might be coming from a leaking hydraulic tube (2nd pic), but I'm not sure. Although there's plenty of weeping around that area. I tightened the nut, but it was already very tight. Any ideas? Sorry if this is a dumb/obvious question but I'm still learning.





Also, what smells like gas appears to be leaking from this bolt area in front of the eagle hitch. This seems an odd place for fuel to leak. Should I be concerned, or just tighten the nut up as best I can and live with it? For me, though, loose fuel has a high pucker factor.



Thanks for your collective wisdom.

Put some Dye-lite in the oil systems and it will tell you right where the leak is. O'Reilly's auto part store sell it part number TP-3090

It appears your vent/leak off line is plugged. Your eagle hitch piston seal is probably leaking bye, filling the rock shaft housing with oil mixed with grease from those grease zerks on the back. The oil is seeping out the right side of the rock shaft at the control block as there is no shaft seal on that side as there is on the left side. The purpose of that vent/leak off line is to convey minor piston seal leakage back to the torque tube but if the tube is plugged or the leakage excessive, the oil seeps out as described above.

Here is how to check if the above is the problem:

Piston seal leak bye oil ends up in the rockshaft housing and is conveyed back to the torque tube sump via the vent/leak off tubing. To check rate of piston seals leak bye disconnect the tubing at the fitting on the rockshaft. Run the engine and cycle the hitch up & down about 10 times to clear any residual oil in the housing and to check that the leak off is not plugged. The leak off can get plugged with old, hard grease, After the 10 cycles, leave the draft arms up with preferably some weight. Any oil dripping from the leak off fitting can only be some residual oil or leak bye of the piston seals. The residual drip will eventually stop and any further oil leaking is the piston seal leak bye rate.

I haven't been able to post a pic. The vent/leak off line is the 1/4" fitting/tubing on the bottom of the rock shaft that you have circled in your 2nd pic.

Joe

Looking at your 2nd pic the above description I wrote still applies and the piston seals are leaking. When the Eagle hitch draft arms are raised the piston is forced down displacing the air/oil cavity in the rockshaft. That air/oil pressure can be nearly as much as the 800 - 850 psi maximum hydraulic pressure applied to the piston top. That indicates the vent/leak off line fitting is simply leaking at that high pressure or the line is plugged. In any event you need to check the piston seal leakage. Your piston probably has 2 O-rings or it can be the older style piston with a leather cup.

Joe

Thanks guys for the info. I was planning on checking (and replacing for good measure) the piston seals when I do the refurb on the VAC. However, I was hoping to get one good mow done
before I do that, but it looks like there are just too many problems with this thing to do that. I just now inspected the transmission fluid level and it's several inches above the fill
line on the dipstick (and it's murky brown liquid), and the torque tube appears to be bone dry. From reading past posts on this issue, it sounds like I might have a blown seal in the
hydraulic pump. Apparently, the hydraulic pump driving gear is in a space common to the crankcase. This caused the contents of the torque tube to get pumped into the crankcase, which is
presumably why it's overfilled. So, in addition to the aforementioned hydraulic piston seal/blocked line, I have this problem too. Oh, well. Guess I'll haul her back to the garage, empty
the liquids and start the teardown.

The hydraulic pump is mounted on the right front of the engine and driven off the engine gear train. The pump shaft seal will leak into the engine crankcase not the transmission. Your low torque tube oil level is probably low due to the external leak and lack of attention to the checking and topping off the oil. The high oil level in the transmission is probably due to water and emulsified oil. Let the tractor sit for a couple days and then crack the drain plug and see how much water drains off. Be very careful cracking the drain plug, just back off far enough to have the water continue to drain. If the drain plug is all the way out it is very difficult to start the threads again to screw it back in with water/oil pouring out.There is 7 gals oil to normal fill and probably much more as axles are flooded.


Joe

Just testing the pic upload now that Chris has worked out a possible fix.

Joe

(quoted from post at 16:23:36 10/19/18) The hydraulic pump is mounted on the right front of the engine and driven off the engine gear train. The pump shaft seal will leak into the engine crankcase not the transmission. Your low torque tube oil level is probably low due to the external leak and lack of attention to the checking and topping off the oil. The high oil level in the transmission is probably due to water and emulsified oil. Let the tractor sit for a couple days and then crack the drain plug and see how much water drains off. Be very careful cracking the drain plug, just back off far enough to have the water continue to drain. If the drain plug is all the way out it is very difficult to start the threads again to screw it back in with water/oil pouring out.There is 7 gals oil to normal fill and probably much more as axles are flooded.
Joe

Click to expand...

Joe, thanks so much for all the good, detailed info - very much appreciated. That's good news to me, actually, about the low torque oil level and high transmission fluid level. I'll crack that plug tomorrow as you recommended and drain any water off. I suspect, since it was sitting idle in a field for at least a year, that it probably does have water in the transmission fluid. If what you say is the case here (no pun intended), then I should just be able to fill up the torque tube with 10w-30(?) and then I should be okay to go, right? After I rebuild it, I'll of course replace the transmission fluid with some 90w transmission fluid (I don't plan on running it during cold months.) Maybe that'll get me going at least long enough to get one good mowing in before the weather turns and I tear it down for a full restoration. The leaky piston rings will have to wait until then I think. The lift system should work well enough for one mowing I would think.

Just looking at your pics again. Must be a 1949 or 1950 tractor, leak is just below the gas tank. Not sure which side sediment bowl is those years but would be prime suspect, along with tank bottom rusted through in a spot.

Joe

dont be surprised if you get a gallon of water

Thanks Ken and thanks again Joe. I'll check out that leak again tomorrow and see if I can trace it better. The prior owner said he had the gas tank relined last year, so I would hope it's not a tank leak. The sediment bowl looked okay to me on a cursory inspection, but I've got a new gasket for it on the way just in case anyway. The sediment bowl is located slightly forward of this area too, about maybe 1' to 1.5' away. It seems like fuel is leaking out of the circled bolt, but perhaps fuel's dripping onto it from above.

Yeah, I won't be too surprised. It was sitting out in a field for over a year, possibly longer, in all sorts of weather. The shifter boot isn't watertight, so I wouldn't be at all surprised if a lot of water got in there.