starting in cold

[Dan W]

I have run heavy equip . for years , I know who cares . Every book and the mechanics Ihave been around say stall the hyd . to warm up . That means pull theboom and stick back until it goes to relief . Works quite well . You folks are a little paranoid . A hydro is not going to warm up sitting idling . I know you have spent lot's on these little tractors , but they will take a cold start . As for the engine , get it running ,give it half throttle get the juices flowing .

Kevin,
I guess you are correct in a manner of speaking, things do heat up quick when you stall the hydralics.
It is all about who pays for the equipment.
In my experience, (having to fix equipment out on the job site) whether it was trucks, loaders or dozers, we had people start all the equipment and let everything run for an hour before any operators or drivers started their shift.

 

[MHarryE]

Think about how cold. Below zero F can be tough on hydraulics due to filters and high oil viscosity. Tractors with suction filters - pumps can cavitate if the engine speed is higher than low idle for the first several minutes. Hydro charge filters can create high back pressure that even the filter bypass cannot handle. My machines with several pumps - I had long warming times based on 10 degree C increments - extending out as far as 30 minutes at low idle before speeding up. High idle immediately on startup and risk blowing the hydro charge filter seal. We only use fine mesh strainers for the gear pump inlets because our experience was suction filters create so many early hour failures due to operators trying to run hard before the oil is warm. Some makers compensate - I see that John Deere has a low viscosity oil for their hydro tractors. Kubota has their Super UDT2 that has better cold flow to prevent problems. A neighbor blew the rear crankshaft seal on his one year old New a Holland due to high speed cold engine operation. New holland said they would give him one but from now on use a 0W or 5W synthetic and let it warm up a long time before going to high idle. So now he is running 5W-40 Mobil 1 heavy duty Diesel engine oil and goes back inside to drink a cup of coffee after starting. No problems so far this year - our coldest this month has been -34.

 

[Dan W]

Think about how cold. Below zero F can be tough on hydraulics due to filters and high oil viscosity. Tractors with suction filters - pumps can cavitate if the engine speed is higher than low idle for the first several minutes. Hydro charge filters can create high back pressure that even the filter bypass cannot handle. My machines with several pumps - I had long warming times based on 10 degree C increments - extending out as far as 30 minutes at low idle before speeding up. High idle immediately on startup and risk blowing the hydro charge filter seal. We only use fine mesh strainers for the gear pump inlets because our experience was suction filters create so many early hour failures due to operators trying to run hard before the oil is warm. Some makers compensate - I see that John Deere has a low viscosity oil for their hydro tractors. Kubota has their Super UDT2 that has better cold flow to prevent problems. A neighbor blew the rear crankshaft seal on his one year old New a Holland due to high speed cold engine operation. New holland said they would give him one but from now on use a 0W or 5W synthetic and let it warm up a long time before going to high idle. So now he is running 5W-40 Mobil 1 heavy duty Diesel engine oil and goes back inside to drink a cup of coffee after starting. No problems so far this year - our coldest this month has been -34.

all of your comments are very well said MHarry,
The cause of failure (due to cold start) becomes obvious when you pull a pump off for tear-down. The metallic damage is serious and damaged parts are usually not reusable . The Labour is high as well because the complete hydro system needs to be disassembled to flush out metalic contamination. So a wee bit of low idle warming-up is not such a bad idea.
Dan