Importance of warming up a hydaulic drive?

[Woodworks]

Just got a SH Gehl pivot steer. The manual states that it should be left running but not driven for 3 mins on start up. Not used to a hydraulic drive what harm comes from hopping on and driving straight away? 

[Richard 1234]

If it’s anything like my big mowers. It’s just to warm the oil up so that you aren’t forcing it through the filters until is gone that bit thinner. Mower has a light that switches off after oil is at the right temp. In practice I don’t think it makes much difference but I let it warm through anyway

[gdh]

Not sure at a technical level but our kramer is always slow for the first minute, especially in cold weather, and I've never had any problems from using it straight away after 4000hours.

[Matthew Storrs]

24 minutes ago, Richard 1234 said:

If it’s anything like my big mowers. It’s just to warm the oil up so that you aren’t forcing it through the filters until is gone that bit thinner. Mower has a light that switches off after oil is at the right temp. In practice I don’t think it makes much difference but I let it warm through anyway

I was thinking it’d be for this reason, but then it doesn’t really make sense, as say in a cold country in minus temeperatures it’d take longer than 3 mins for the hydraulic fluid to get to the same temperature as a machine in a hot country that’s only just been started.

Personally with my digger I let the oil warm up with some idling followed by gentle ‘exercises’ before subjecting it to proper work.

Fine if you are going to be using it for 8 hours not so if just need to move a load of logs!

[Richard 1234]

I was thinking it’d be for this reason, but then it doesn’t really make sense, as say in a cold country in minus temeperatures it’d take longer than 3 mins for the hydraulic fluid to get to the same temperature as a machine in a hot country that’s only just been started.
Personally with my digger I let the oil warm up with some idling followed by gentle ‘exercises’ before subjecting it to proper work.
Fine if you are going to be using it for 8 hours not so if just need to move a load of logs!

That makes sense. The manuals on my mowers say wait till the light goes off not a specific time. Early and late season grass cutting the light can take between about 5 and 8 mins to go off. From now until September it’s usually off within 1 minute.

[Woodworks]

7 minutes ago, gdh said:

Not sure at a technical level but our kramer is always slow for the first minute, especially in cold weather, and I've never had any problems from using it straight away after 4000hours.

That's what I want to hear. I dont mind 3 mins for the first run of the day but would like to start straight away once it's been run. It works fine from cold but dont want to balls it up through ignorance. 

[drinksloe]

Was it not a thing when Turbo desiel engines 1st came out u were meant to let it idle for 1-2mins after a long run to let engine/turbo cool down? U do it a couple of times then just carry on as normal.

Never hear of it now

 

Must admit with most machines (esp if not worked that much/hard) i tend to give them a few mins warm up or working at low revs and build up more gradually.

Even putting the chipper up to speed i tend to allow it a bit of time them throttle gently a lot of boys just crank it up.

I just thiknk it gives u even 20-30 seconds to hear if machine is making all the right noises before its oing full pelt

[Mick Dempsey]

AFAIK the turbo diesel thing is because the oil around the turbo is very hot, if you turn it off straight from high revs you can get build up of oil crud that has superheated burnt on to something, this potentially shortens the turbos lifespan.

 

We are religious in our warming down of the ST8.

[josharb87]

I thought the turbo thing was because the turbo can still be spinning at maybe 200,000RPM, turning the engine straight off results in the turbo still spinning but dry. Letting it idle first is to let the turbo loose RPM before turning the engine off and subsequently oil supply which lubes and cools the bearings.

 

Be interesting if someone more knowledgeable can give the right answer!

 

Try starting your machine at -10 Woodworks and try driving fast, it won't, oils too thick, all components work harder trying to force the treacle about, be kind and let the oil circulate on idle a minute or two

 

 

[aspenarb]

The turbo run down time and oil thing is from the day of shite oils , not necessary today but its obviously better to turn off a motor from idle rather than rev the balls off prior to shut down. The warm up thing with hydro-static drives is much the same as anything that's about to be worked hard, nothing with bearings belts or hydraulics should be caned when cold.

 

Bob