What's leaking in the shop?
In this edition of Maintenance Q&A, we answer questions from readers who are working on equipment in the shop and have concerns about leaks and hydraulic fittings.
What is leaking?
Q. Deb in North Carolina gets a little jumpy when she sees a puddle of liquid underneath the tractor. Is there a quick way she can decipher what's leaking?
A. John Nowatzki, ag machine systems specialist at North Dakota State University, says the color of the puddle is a clue. Engine oil is amber-colored when it goes in, but it is dark brown to black if it comes out as a leak. If there is water in the oil, you might see a milky-white puddle.
Antifreeze is red or green, but it can look amber-orange.
Transmission fluid from a tractor is also a reddish color, says Nowatzki, with a consistency similar to engine oil.
Tractors with cabs might dribble windshield washer solution, which is usually blue or pink.
An air conditioner condenser can leave a large puddle under the tractor – up to a pint. Nowatzki says some people are alarmed at the puddle, but it is just water and completely normal.
Leaking gasoline will evaporate and you may not see anything on the ground. Diesel would puddle or at least leave a wet mark. “You would certainly have a unique odor from diesel fuel that you wouldn't have from gas,” says Nowatzki.
Q. Charlie in Nebraska has been adding more fluid than usual to his tractor's hydraulic system. If it's a leak, is there do-it-yourself advice he can follow?
A. Aaron Yoder is an Extension ag safety associate at Pennsylvania State University. He says the service life of a rubber hydraulic hose is about 10 years. The most common problem is a pinhole leak, which can be hard to find. Yoder says to start your detective work by parking the tractor on an impervious surface such as concrete, and then begin looking for drips.
“After you think you've located the area, use a piece of cardboard or a piece of paper, then trace behind and around your hoses,” says Yoder. “Eventually, you'll see where it may be squirting out.”
Looking for a pinhole leak can be dangerous if the hose is under pressure. Wear safety glasses and gloves to prevent being sprayed in the face or hands with fluid.
Once you've found the leak, you have to figure out if there's any stored pressure in the hose before attempting a repair. Lower any attachments to the ground and shut the tractor off, which shuts off the hydraulic pump.
“Circulate as many of the levers as you can to equalize the pressure throughout the hydraulic system. That should take it down to zero,” says Yoder.
Put on safety equipment, then start disconnecting the hose.
“If the hose only has a swivel connection on one end, that's the end you have to take off first. Then you need to spin the whole hose to get the other end off,” says Yoder. Lay a rag over the connection as you loosen it, in case there is any fluid still trapped in the hose.
You will be taking off a lot of parts, so it's important to have a system in place for putting them back together again.