Hot Quick-Connect Couplers

[Suburban Plowboy]

I got my new flail mower working again, and I spent around an hour obliterating weeds and little trees.

When I was done, I tried to decouple the hoses, and the couplers were hot. Too hot to handle comfortably. I let the tractor sit for a while.

These hoses have restrictors on them to keep the mower from flying around due to excessive flow. Is it normal for the couplers to get hot? I have used an FEL a lot, but it never occurred to me to feel the couplers to see how warm they were, so I don't know.

Also, I have two rear remote valves and 4 hoses. When I bought the restrictors, I bought one for each hose. In retrospect, that seems stupid, since one restrictor per loop will slow the fluid down. Should I take a couple of the restrictors off?

 

[Shawn T. W.]

Hydraulic fluid get hot, how hot it seems is all perspective ...

I know using my backhoe, that if I place my hand on the cylinder as a hand hold, I'm quickly reminded that it's a bad idea, unless it's winter and I have gloves on!

@kennyd could give you more insite on whether the restrictors are causing excess heat, and if one is good enough in a loop or not ...

 

[404nouser]

They will be about the temp of your transmission.

 

[anomad]

I got my new flail mower working again, and I spent around an hour obliterating weeds and little trees.

When I was done, I tried to decouple the hoses, and the couplers were hot. Too hot to handle comfortably. I let the tractor sit for a while.

These hoses have restrictors on them to keep the mower from flying around due to excessive flow. Is it normal for the couplers to get hot? I have used an FEL a lot, but it never occurred to me to feel the couplers to see how warm they were, so I don't know.

Also, I have two rear remote valves and 4 hoses. When I bought the restrictors, I bought one for each hose. In retrospect, that seems stupid, since one restrictor per loop will slow the fluid down. Should I take a couple of the restrictors off?

So your Bowell is inflamed? That sounds uncomfortable...

I have no idea, just can't pass up a potty joke. The bush hog on my excavator does get rather warm. I just assume that is proper operating temperature under load for the hydraulic oil? It is warm to the touch, but not smoking hot.

 

[kennyd]

It is normal for hydro fluid to be about 100º above ambient temp, so everything in the circuit will assume that temp eventually. Remember that anything about 110º or so 'feels' hot on bare skin.

Or, for short: Normal.

 

[ruffdog]

They will be about the temp of your transmission.

.....and unlike equipment like a skid steer that is made to run hydraulic motors for extended periods, the tractor has limited cooling capacity for the hydraulic fluid.

 

[Suburban Plowboy]

Thanks for all the help.

 

[oldnslo]

Yes orifices create heat so if constantly moving flail the quick disconnects will get hot.

 

[zzvyb6]

The restrictors are the source of the heat. Think of how a shock absorber feels like after driving down a very bumpy road. It restricts flow using valves and orifaces. The fluid flow's mechanical energy is turned into heat via molecular friction.

I suggest a high temperature rated hydraulic oil (ISO 68 or L-HS 46 synthetic). Of course the oriface interface heating will also heat the oil, so make sure your reservoir or cooler is adequate. You might try using just 1 of the oriface slugs if you have 2 in there (1 in each hose's end), and of course, maybe try just one larger diameter one that satisfies the mower speed and temperature issues. You can also consider using the 2 in one hose, 1 at each end will drop the flow (and increase temperatures in stages).

Since you have 2 restrictors, you could try drilling one out a few thou each time, you'd still have the original...