L3540 hydro power questions

[hunt4570]

I have an L3540 Hydrostatic 4 wheel drive tractor, have had it maybe 8-9 years. This problem seems new or has been slowly getting worse and I'm just starting to notice it.. When I have a mower on and either going on flat land or downhill it seems to be fine, BUT on even a slight upgrade I seem to lose power and RPMs pretty bad! I thought it was due to running the finish mower as it seems to take more power than a brush hog, but using the brush hog yesterday it seems the same. I do not use this for business just maintaining my own property so not a ton of hours, bought it with 320 and now has fourteen hundred something. Did the hydraulic oil and filters last year and it just had a recent oil and filter change. Thought maybe it was leaking trans fluid, but I checked, and it was full and crystal clear. Any Ideas before Ie to drag it to the dealer???

 

[rScotty]

Nice photo...
Well, there's really no good reason why a tractor that young would have any change in power. My guess from what you say is the HST is fine. But before taking it to the dealer, I'd want to also make sure that the engine is up to power. Mostly that is going to be fuel and air filters, maybe check the valve clearances, and that the exhaust is not full of carbon. One of ours was down on power from a fuel filter that needed changing.

I mention the exhaust because yours is like mine in being right at the age that saw a changeover from the old interim Tier IV EGR emissions control to the newer full Tier IV emissions with regeneration.
I prefer the older type EGR emissions, but some Kubotas from that era have a pre-muffler that needs to be cleaned or replaced from time to time.

In choosing a dealer for something that is this vague, I'd want a real dealer with an experienced mechanical shop. I had a shop. The shop mechanic is going to need a dynamometer for sure, and either a hydraulic test stand or at least some hydraulic gauges.
Otherwise the mechanic is just guessing, and we can do that here for free.
rScotty

 

[JWR]

Have you made sure the air intake path is 100% clear? My first guess is that air intake is being restricted somehow. Next guess would be fuel flow restriction. Filters and all that...

 

[Chewwy]

Had a similar problem with my L3240 HST. It an inconsistent problem.

Check you fuel filter. Mine had some jelly like substance in it. Replaced it and problem went away.

 

[hunt4570]

Nice photo...
Well, there's really no good reason why a tractor that young would have any change in power. My guess from what you say is the HST is fine. But before taking it to the dealer, I'd want to also make sure that the engine is up to power. Mostly that is going to be fuel and air filters, maybe check the valve clearances, and that the exhaust is not full of carbon. One of ours was down on power from a fuel filter that needed changing.

I mention the exhaust because yours is like mine in being right at the age that saw a changeover from the old interim Tier IV EGR emissions control to the newer full Tier IV emissions with regeneration.
I prefer the older type EGR emissions, but some Kubotas from that era have a pre-muffler that needs to be cleaned or replaced from time to time.

In choosing a dealer for something that is this vague, I'd want a real dealer with an experienced mechanical shop. I had a shop. The shop mechanic is going to need a dynamometer for sure, and either a hydraulic test stand or at least some hydraulic gauges.
Otherwise the mechanic is just guessing, and we can do that here for free.
rScotty

Thanks, my dealer here has been very good to me over the years.

 

[hunt4570]

Have you made sure the air intake path is 100% clear? My first guess is that air intake is being restricted somehow. Next guess would be fuel flow restriction. Filters and all that...

Thanks, but it's been a little while sense I have checked, and I will do that!

 

[hunt4570]

So I'll check fuel and air filters this week, thanks guys and I'll let you know what I find out!

 

[hunt4570]

I replaced air and fuel filters yesterday, nothing seemed different just driving it around, if it ever quits raining, I'll hook a mower up and check it out.

 

[rScotty]

I replaced air and fuel filters yesterday, nothing seemed different just driving it around, if it ever quits raining, I'll hook a mower up and check it out.

Does the L3540 have a fuel lift pump? I just replaced that on our JD which had a problem running out of power at high revs.
I also used an air compressor to shoot air back down the fuel line to clean out the pick up fllter in the fuel tank. With the filler cap off I could see it bubble, so that line was clear.

 

[hunt4570]

Does the L3540 have a fuel lift pump? I just replaced that on our JD which had a problem running out of power at high revs.
I also used an air compressor to shoot air back down the fuel line to clean out the pick up fllter in the fuel tank. With the filler cap off I could see it bubble, so that line was clear.

I have no clue about the fuel lift pump but since my fuel tank is above the engine I doubt it. I'll have a look at the manual, thanks. Where did you detach the fuel line to blow it out?