Hard freeze, now hydraulic leak on B7100

Bluelick · Jan 6, 2018

Hey folks,
We have had some very cold (for us) weather here in Kentucky over the last week, -4 one night, -2 another. Yesterday I saw a stain of fluid on the ground under my B7100 in front of the mowing deck, and a drip coming off the bottom of the engine. I put some newspaper there to get a better look at what's coming out. It seems clear although tinged with black grit, probably from running down the engine. I'm assuming it's hydraulic fluid. I don't know what would have caused this from cold temps, any thoughts?
Thanks!
Bluelick

/pine · Jan 6, 2018

Bluelick said:
Hey folks,
We have had some very cold (for us) weather here in Kentucky over the last week, -4 one night, -2 another. Yesterday I saw a stain of fluid on the ground under my B7100 in front of the mowing deck, and a drip coming off the bottom of the engine. I put some newspaper there to get a better look at what's coming out. It seems clear although tinged with black grit, probably from running down the engine. I'm assuming it's hydraulic fluid. I don't know what would have caused this from cold temps, any thoughts?
Thanks!
Bluelick

One possibility is there was some water trapped in a fitting etc. that froze and expanded causing a small crack etc...

TheMan419 · Jan 7, 2018

It would appear most hydraulic fluid appears to have a freeze point of -40F. We were down to -15 ambient air temperature a few days ago and no ill effect on my hydraulic fluid. I would suspect there was some water somewhere that froze and caused trouble. Possibly an O ring or something cracked.

Egon · Jan 7, 2018

Should be two hydraulic lines in that area that go to the oil cooler.

best start tracking the leak to find out where it originates. Wipe all down with a rag so it's easier to see fresh oil.

Dave M7040 · Jan 9, 2018

Bluelick said:
Hey folks,
We have had some very cold (for us) weather here in Kentucky over the last week, -4 one night, -2 another. Yesterday I saw a stain of fluid on the ground under my B7100 in front of the mowing deck, and a drip coming off the bottom of the engine. I put some newspaper there to get a better look at what's coming out. It seems clear although tinged with black grit, probably from running down the engine. I'm assuming it's hydraulic fluid. I don't know what would have caused this from cold temps, any thoughts?
Thanks!
Bluelick

Invest in some UV leak detection equipment. Makes finding the source of a leak very easy.

You add a small packet of UV dye to the tractor system you suspect, in your case the hydraulic system.

You run the machine for an hour or twwo and then, using a UV flashlight start scanning or lighting up the underside of your tractor.

The leaking fluid will glow and it is easy to see where it originated.

Look at these youtube videos to understand how the process works and then shop around for an inexpensive system

Spectroline’s OPK-441 leak detection kit - YouTube

How To Find And Fix Car Oil Leaks - YouTube

These UV systems originated for the air conditioning industry where it was a gas that was leaking not a liquid so much harder to find.

Often, older O rings in cold weather loose their resiliency and leak but once things warm up the leak stops.

Dave M7040

Bluelick · Jan 12, 2018

Thanks all for those leads--I love the UV trick! It was warmer this week but work had me tied up and now it is going to get cold and snowy again, so this may need to wait a bit longer but I really appreciate the help!