GC1700 series fast dump loader function??

bartjoebob · Nov 19, 2017

Both the manual and sticker next to the loader joystick indicate there is a fast dump mode for the loader bucket on a new GC1705. I have no trouble with float mode but cannot seem to get the bucket to tip any faster than a slow roll. I thought this might be more like a release and gravity dump. Any thoughts on this? Or is this function not really that substantial with a GC series running a DL95 loader?

coldsteelva · Nov 20, 2017

It depends on how much weight you're trying to tip out/dump, plus the hydraulic fluid still needs to move in order for the cylinder to extend using the weight of the load to 'pull' the bucket. I agree that it isn't an insta-dump, but I think the return line ID is the limiting factor.

teg · Nov 20, 2017

I have that "feature" on my tractor... like you, I wasn't impressed.

frugalangler · Nov 20, 2017

I've used it - it definitely is load dependent, empty bucket doesn't dump much faster, but full of dirt or gravel and it will definitely spill it's load quicker, but not immediately.

JWR · Nov 20, 2017

I have that feature on a MF 2660 81 horse tractor. Pure pain in the butt and of no real value. Something to add complexity and haunt you eventually. First off, it just allows a gravity dump if you have a heavy bucket load to go faster than it would under power. Whoopeee. Apparently the feature was intended for commercial users of larger tractors where time equals money and someone probably lobbied for the feature (or more likely the foolish marketing people THOUGHT someone wanted it.) In any case the primary result is a more complex and expensive loader valve which is finicky to adjust and more prone to failure. I have been so P.O.'d at that loader valve ... long story involving not only a bad original from the factory but another bad one from AGCO depot parts via a dealer. Would not allow forcing the bucket tip down in curl. Eventually fixed it myself using a kit from the valve manufacturer (Nimco.) Over the next 3yrs the loader valve developed complete slowdown and "won't work at all" until the oil gets hot. That is cause for a new set of seals which a dealer says will cure the issue. In my book the BEST loader valve is the simplest one, typical of small to medium sized farm tractors that has NO special features, NO fast dump and just does what it is told to do. I'm literally ready to throw this $1100 loader valve away and put on a simple one if the new seals don't solve the problems.

Snobdds · Nov 20, 2017

It seems to work really well on my 1710. It's not just the normal move to the right of the loader control stick. It really has to be as far right as the loader control stick will go. It works if there is a load in the bucket or not.

JWR · Nov 20, 2017

Snobdds said:
It seems to work really well on my 1710. It's not just the normal move to the right of the loader control stick. It really has to be as far right as the loader control stick will go. It works if there is a load in the bucket or not.

I realize that is how it operates (mine did too, just not very well and got worse.) The reason it works in the "far right" joystick position regardless of whether you have a load in the bucket is that the bucket itself is forward of the pivot point for curl and has enough weight of its' own to cause gravity curl. I just meant that havng a good load in the bucket makes that curl fast and that (fast dump) was the purpose of the feature.

Glad your's work's well.

AxleHub · Nov 26, 2017

Just a reminder to readers, that JWR has and is referring to his 2660 81 HP tractor, which is a much different unit than a gc1700 series.

jeepcj7 · Nov 28, 2017

It was once explained to me like this: the original purpose of "Fast Dump" was not fast dump at all, it was to keep the bucket cylinders from cavitating when dumping a loaded bucket at low rpm's. By that I mean the bucket cylinders could extend faster than the pump could replenish the oil in the cylinder sucking air into the cylinder from the reservoir. As a benefit, the bucket would actually dump a little faster hence the term "fast dump" (sounds better than "cavitation prevention device"). It does this by opening a passage in the loader valve between the rod and barrel ends of the lift cylinders. Now concerning the GC, dump time with a loaded bucket at typical operating speed (say around 1800 pm) is about 4 seconds. Fast dump makes dumping a loaded bucket about 20% faster - so dump time is now about 3.2 seconds. Personally I will never notice 0.8 seconds difference in dump time, but i do appreciate the fact that it helps to keep the bucket cylinders from cavitating.