CaveCreekRay
Well-known member
Lifetime Member
Equipment
L3800 HST, KingKutter box scraper, KingKutter 66" rake, County Pride Subsoiler
Got my L-3800 back from the dealer yesterday after experiencing some problems...
HST Pedal-
The HST pedal would get really stiff after about ten minutes of use. Plus, the HST bypass valves were squealing like piggies when you'd just barely press the pedal in high range both in FWD and REV.
The tech said the most likely cause was the HST bypass valves were going bad so, before splitting the tractor, he swapped out both valves (I believe located under the tranny top under the seat). Its a tad quieter (maybe 10%) but after driving it around the block to warm up the transmission, the pedal feel is uniformly even after warm up. I'll really test it after the ground dries up a bit after nearly 2" of rain in two days...
The tech said that the HST systems hardly ever have a problem. When they do, its most often due to foreign material (sand/dirt/metal) that finds its way into the brass pivot plate that controls the HST FWD-REV pressure apportionment to the motor. I am lucky that my fluid in 260 hours is still clear as water and the filters have been changed three times thus far due to repairs (3-pt) and service schedule. I asked Justin if I should swap over to synthetic sooner and he said it wasn't necessary until I got closer to 400 hours. I remember how absolutely immaculate my rear end innards looked when the had it apart for the 3-pt valve swap.
Loader Weak-
I had noticed my loader kind of losing its "grunt" for picking things up. I also noticed a weirdism in the loader control lever after shutdown.
I usually back the tractor into its garage and shut it down. Then. I lower the implement onto a rubber mat, as I do the FEL. Originally, with the engine off, the FEL would go down proportionally as fast as you pushed the lever. More lever, faster down. Then one day, you could only get the FEL down with about 1/4 of the DOWN lever. Any more and the FEL would nearly stop dropping. About that time, I noticed that the loader, when heavily loaded, kinda looked a little "tweaked" as in, not quite level.
The service tech put the loader actuators under test and found one was bypassing internally. No leaks outside but the seal inside was not holding pressure -bypassing it, which explains the weird lever operation when off as well as the "catty-whompus" (sorry for the technical term) "set" to the loader under load.
My service tech is the same guy who solved my jerky 3-pt problem two years ago and is a really sharp guy. I asked him if rebuilding a cylinder was something a guy could do at home and he said "Sure, I don't see why not." He went on to say that the spanner needed to unscrew the end of the lift cylinder was available at many auto parts stores for around $20. The only problem is the cylinder end is screwed on with 500 ft lbs of pressure!!! Coming off requires more effort.
He said in the field, he leaves the end of the loader arm attached to the frame and cranks on the cylinder from there. At the shop, they have a metal table weighing close to 1000 lbs with a jig setup to hold the cylinders. They must have a 48" cheater bar to yam on those cylinder ends!!! Once apart, the disassembly is relatively simple regarding seal swap as long as the cylinder is not bent from moving huge slabs of concrete or giant cacti. Getting the cylinder re-torqued takes some ingenuity.
In a worst case scenario, you could have your dealer crack the cylinder when you drop down to pick up your seal kit. Take the kit and cylinder home, do the swap and then take it back to have them crank it down. That would probably save you $50 from having them do the whole shebang in-shop. The kit was $65 for the lift cylinder.
After seal swap, the FEL operates like it used to originally after shutdown. More lever=more movement.
Anyone out there done any cylinder work? Suggestions or techniques would be appreciated.
Ray
PS. More stuff I learned about my tractors hydraulic system.
I always thought there was one hydraulic pump on my 3800 HST that ran everything. Justin told me there are actually three on board. One big one for the HST which puts out more than the HST can ever handle meaning the bypass valves always bypass some of the fluid going to the drive motor. Those are the valves he changed.
There is a dedicated power steering pump.
There is an implement pump which runs the FEL and 3-pt.
Hope this helps...
Ray
HST Pedal-
The HST pedal would get really stiff after about ten minutes of use. Plus, the HST bypass valves were squealing like piggies when you'd just barely press the pedal in high range both in FWD and REV.
The tech said the most likely cause was the HST bypass valves were going bad so, before splitting the tractor, he swapped out both valves (I believe located under the tranny top under the seat). Its a tad quieter (maybe 10%) but after driving it around the block to warm up the transmission, the pedal feel is uniformly even after warm up. I'll really test it after the ground dries up a bit after nearly 2" of rain in two days...
The tech said that the HST systems hardly ever have a problem. When they do, its most often due to foreign material (sand/dirt/metal) that finds its way into the brass pivot plate that controls the HST FWD-REV pressure apportionment to the motor. I am lucky that my fluid in 260 hours is still clear as water and the filters have been changed three times thus far due to repairs (3-pt) and service schedule. I asked Justin if I should swap over to synthetic sooner and he said it wasn't necessary until I got closer to 400 hours. I remember how absolutely immaculate my rear end innards looked when the had it apart for the 3-pt valve swap.
Loader Weak-
I had noticed my loader kind of losing its "grunt" for picking things up. I also noticed a weirdism in the loader control lever after shutdown.
I usually back the tractor into its garage and shut it down. Then. I lower the implement onto a rubber mat, as I do the FEL. Originally, with the engine off, the FEL would go down proportionally as fast as you pushed the lever. More lever, faster down. Then one day, you could only get the FEL down with about 1/4 of the DOWN lever. Any more and the FEL would nearly stop dropping. About that time, I noticed that the loader, when heavily loaded, kinda looked a little "tweaked" as in, not quite level.
The service tech put the loader actuators under test and found one was bypassing internally. No leaks outside but the seal inside was not holding pressure -bypassing it, which explains the weird lever operation when off as well as the "catty-whompus" (sorry for the technical term) "set" to the loader under load.
My service tech is the same guy who solved my jerky 3-pt problem two years ago and is a really sharp guy. I asked him if rebuilding a cylinder was something a guy could do at home and he said "Sure, I don't see why not." He went on to say that the spanner needed to unscrew the end of the lift cylinder was available at many auto parts stores for around $20. The only problem is the cylinder end is screwed on with 500 ft lbs of pressure!!! Coming off requires more effort.
He said in the field, he leaves the end of the loader arm attached to the frame and cranks on the cylinder from there. At the shop, they have a metal table weighing close to 1000 lbs with a jig setup to hold the cylinders. They must have a 48" cheater bar to yam on those cylinder ends!!! Once apart, the disassembly is relatively simple regarding seal swap as long as the cylinder is not bent from moving huge slabs of concrete or giant cacti. Getting the cylinder re-torqued takes some ingenuity.
In a worst case scenario, you could have your dealer crack the cylinder when you drop down to pick up your seal kit. Take the kit and cylinder home, do the swap and then take it back to have them crank it down. That would probably save you $50 from having them do the whole shebang in-shop. The kit was $65 for the lift cylinder.
After seal swap, the FEL operates like it used to originally after shutdown. More lever=more movement.
Anyone out there done any cylinder work? Suggestions or techniques would be appreciated.
Ray
PS. More stuff I learned about my tractors hydraulic system.
I always thought there was one hydraulic pump on my 3800 HST that ran everything. Justin told me there are actually three on board. One big one for the HST which puts out more than the HST can ever handle meaning the bypass valves always bypass some of the fluid going to the drive motor. Those are the valves he changed.
There is a dedicated power steering pump.
There is an implement pump which runs the FEL and 3-pt.
Hope this helps...
Ray
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