Weak HST

[AceDeuce]

My '03 BX just doesn't seem to have the same "umphf" that it used to. Engine runs like a top but the trans will stall under less load than when it was new. Is there a relief valve that can be adjusted? Just want to get it tuned up to like-new pulling power.

 

[dex3361]

My '03 BX just doesn't seem to have the same "umphf" that it used to. Engine runs like a top but the trans will stall under less load than when it was new. Is there a relief valve that can be adjusted? Just want to get it tuned up to like-new pulling power.

Which BX is it? Have you changed the HST fluid and filters? Is it stalling the motor or stalling the hydro like it does in high range with to much load?

 

[AceDeuce]

BX1500 with about 435 hours on the clock. I change the Hydro fluid and filter every 100 hours or so---last change was at 400. It's the hydro that is stalling. The engine continues to run without even really lugging that much, let alone stalling. Typically happens in high range going up hill, but it didn't used to when it was newer.

 

[dex3361]

Do you have the parts manual for the BX1500?

 

[dillo99]

I know you say your engine isn't lugging but when was the last time you cleaned or changed your air filters. I was having a high gear/hill problem too and it turned out to be that it just wasn't getting the air that it needed. Cleaned the filters and all was back to normal.

 

[botakix]

i have a L3130 with hst, and am having the same problem. i changed hyd. fluid and filters but didnt seem to help. mine seems to be at its worst, when in medium range. seems to bog out a little when going up even small hills, even when you let off pedal a little, to let it gear down a little. i was pulling a 8ft chain harrow through the pasture the other day, knocking down manure piles, and seemed to stuggle pulling the chain up hill. tried using high to start out, just to see what would happen, and would stall out trying to start up a hill in high with harrow behind. i assumed this was probably normal in high, but feel like is should pull a little better and faster in medium, with such a small strain, as a chain harrow with a rr tie on top. gonna try and change air filters next, but really starting to think it is just the nature of the beast, with these hst transmissions.

 

[dex3361]

I checked the repair manual and the HST for a BX1500 has a relief valve. The first thing to do would be to check the relief vale pressure and see if it is in spec. You will need a gauge and the adapter to attach the gauge to the port.

 

[AceDeuce]

I checked the air filter and it is clean. Have a parts manual. Where is the relief valve? The HST is a complicated beast! What is the adjustment? Adding shims?

 

[dex3361]

How does the tractor pull in reverse? There are separate reliefs for forward and reverse. I attached 2 different files on the hydraulics of the machine and should point you in the right direction. Did you clean the suction screen when you serviced the tractor?