leonz
Super Member
Very true,
I would venture that his gear pump has a very large leak through the bronze thrust plates as well.
hyraulics question
- Thread starter MattJ
- Start date
- Views: 14594
Very true,
I would venture that his gear pump has a very large leak through the bronze thrust plates as well.
Tore down the pump, it looks like the day it was made. The whole rest of the HST does too. I am going to talk to the dealer this week and see if we can talk to Kubota about it and get their response.
It just doesn't seem right that this wear should have happened so early on. It also wasn't like I drove it a long time from when the chattering first occurred. It started happening less than an hour back on the engine clock. As soon as I noticed chattering under load I garaged it and only have run it when I was testing the pressure readings and replacing parts.
It just doesn't seem right that this wear should have happened so early on. It also wasn't like I drove it a long time from when the chattering first occurred. It started happening less than an hour back on the engine clock. As soon as I noticed chattering under load I garaged it and only have run it when I was testing the pressure readings and replacing parts.
jerkyboy
Silver Member
Matt, great post with excellent info. I too have a HST problem with my 460 hour BX1500. The tranny chatters under load and "disconnects." It is much worse in reverse than forward. I first noticed it a couple weeks ago when I was moving six yards of crusher run with my FEL. Can you suggest where I should buy a gauge setup to read my hydraulic pressure, how easy it is to get at the priority valve, and is the tear down to remove the HST pretty straight forward? I was thinking my tranny was shot and got a quote from bigorangeparts for $515 to my door.
leonz
Super Member
Matt-
if you have the pump back together do one thing fo rme to satisfy my curiousity if you dont mind;
put the pump on its side in a vice with the inlet side up and take a cup of the UDT or whatever you are using and pour it in the inlet side of the pump which is the larger port then:
wait for the oil to drip through. If there is more than a pencil lead thickness
of oil exiting the pressure side of the pump the pump is shot.
This is the quickest way to detemine if a gear pump is bad if you cannot flow rate it at a hydraulic repair shop.
if you have the pump back together do one thing fo rme to satisfy my curiousity if you dont mind;
put the pump on its side in a vice with the inlet side up and take a cup of the UDT or whatever you are using and pour it in the inlet side of the pump which is the larger port then:
wait for the oil to drip through. If there is more than a pencil lead thickness
of oil exiting the pressure side of the pump the pump is shot.
This is the quickest way to detemine if a gear pump is bad if you cannot flow rate it at a hydraulic repair shop.
The testing of pressures is pretty easy. I don't have the work shop manual for your tractor, but for mine here's what I did.
To test max pressure coming out of the initial charge pump I got a 5000 psi gauge and a quick connect both from agrisupply that could snap onto one of my loader ports. With the tractor running actuate the loader controls in that direction and hold it briefly until you hear the relief valve kick in and note the reading.
For charge pressure the port on mine was near the transmission oil filter. When looking at the base of the filter there were two ports next to it and the one to the left was for charge pressure (please check your tractors parts diagram which you can get on messicks website to make sure). On mine it was a M14x1.5 fitting and the pressure range was something like 40-75 psi in the manual. To test it I went to autozone and got a cheap oil pressure gauge kit (around $25) and it came with the gauge, lines and metric adapters. I then got the port fitting for the M14 from northern tool. Drop the port, add this setup, and run the tractor at full throttle and I also drove it under load to see if it could hold charge pressure (mine dropped like a rock initially).
For the pressure generated by the HST pump I needed a 3/4 hydraulic fitting, hose and I just hooked up the pressure gauge I used on the loader port with some adapters from northern tool. The ports are under the tractor, on the direct bottom of the HST. On mine you'll see three in a row, the outer two are for the front and reverse testing ports, and the middle is the charge relief valve assembly. You hook up the tester, run at full throttle with the brake on or against a tree, and apply the HST forward or back and look to see when the relief vavle kicks in. Mine should be 1900 psi, but the HST couldn't build past 1100.
So for testing I was in between the WSM and parts about $160 or so. The dealer can probably test for this or less but I like to learn and understand.
As for the tractor tear down. The workshop manual and printed parts explosions were a must for me, perhaps not for others but at a minimum it lists torque specs. It took me about 4hrs or so before I had the HST out, since you need to take everything off the back of the tractor down to the frame. Tools required are metric wrenchs and sockets from around 8mm to 24mm, a retaining clip wrench for the drive shaft removal, a breaker bar for the sockets, a metric hex set including 5, 6, and 7mm, and a torque wrench for when you put it all back together. You'll also need a place you can make a mess, and a lot of shop rags!
So I'll let you make the call. There's no doubt its a lot of work. I'ld also recommend you have a good place to layout all the parts you have to tear off this as you get to the HST.
- Matt
To test max pressure coming out of the initial charge pump I got a 5000 psi gauge and a quick connect both from agrisupply that could snap onto one of my loader ports. With the tractor running actuate the loader controls in that direction and hold it briefly until you hear the relief valve kick in and note the reading.
For charge pressure the port on mine was near the transmission oil filter. When looking at the base of the filter there were two ports next to it and the one to the left was for charge pressure (please check your tractors parts diagram which you can get on messicks website to make sure). On mine it was a M14x1.5 fitting and the pressure range was something like 40-75 psi in the manual. To test it I went to autozone and got a cheap oil pressure gauge kit (around $25) and it came with the gauge, lines and metric adapters. I then got the port fitting for the M14 from northern tool. Drop the port, add this setup, and run the tractor at full throttle and I also drove it under load to see if it could hold charge pressure (mine dropped like a rock initially).
For the pressure generated by the HST pump I needed a 3/4 hydraulic fitting, hose and I just hooked up the pressure gauge I used on the loader port with some adapters from northern tool. The ports are under the tractor, on the direct bottom of the HST. On mine you'll see three in a row, the outer two are for the front and reverse testing ports, and the middle is the charge relief valve assembly. You hook up the tester, run at full throttle with the brake on or against a tree, and apply the HST forward or back and look to see when the relief vavle kicks in. Mine should be 1900 psi, but the HST couldn't build past 1100.
So for testing I was in between the WSM and parts about $160 or so. The dealer can probably test for this or less but I like to learn and understand.
As for the tractor tear down. The workshop manual and printed parts explosions were a must for me, perhaps not for others but at a minimum it lists torque specs. It took me about 4hrs or so before I had the HST out, since you need to take everything off the back of the tractor down to the frame. Tools required are metric wrenchs and sockets from around 8mm to 24mm, a retaining clip wrench for the drive shaft removal, a breaker bar for the sockets, a metric hex set including 5, 6, and 7mm, and a torque wrench for when you put it all back together. You'll also need a place you can make a mess, and a lot of shop rags!
So I'll let you make the call. There's no doubt its a lot of work. I'ld also recommend you have a good place to layout all the parts you have to tear off this as you get to the HST.
- Matt
EE_Bota
Elite Member
My best guess about the failure is the charge pressure issue, followed by the fan issue. The charge tops up the unit, and accounts for it's ability to lubricate moving parts, and swap some fluid, which should have the effect of swapping some heat to the broader gearbox and making sure new fluid comes in with adequate lubricity.
It is possible that this was compromised causing increased heat and air entrainment, with "dieseling" of air bubbles resulting.
Some of this may be helpful to some. I wrote what I wrote above without consulting the links below, so in case of discrepency, go with the links, not me.
Air Contamination of Hydraulic Fluid
Hydrostatic Transmission,Hydrostatic Transmissions
Hydrostatic Transmission, Hydrostatic Transmissions
It is possible that this was compromised causing increased heat and air entrainment, with "dieseling" of air bubbles resulting.
Some of this may be helpful to some. I wrote what I wrote above without consulting the links below, so in case of discrepency, go with the links, not me.
Air Contamination of Hydraulic Fluid
Hydrostatic Transmission,Hydrostatic Transmissions
Hydrostatic Transmission, Hydrostatic Transmissions
Sorry, about the question for replacing the flow priority valve. Its a really easy piece to get to. On mine remove the left rear tire, and the valve is sitting right there and can be removed easily. Looking at the parts diagram would be easier than me explaining it. Its part of the whole unit that controls the flow of hydraulic fluid to the FEL, 3-pt, and power steering.
jerkyboy
Silver Member
Thanks Matt, I appreciate the update. I'm going to see if the dealer I bought it from will take a look and maybe do something for me, as I've only put a little over 40 hours on it since I took it home. If not, looks like I'll have a nice fall project
.
jerkyboy
Silver Member
Where did you order the pump and fan from and how much? OBTW, the dealer I bought the tractor from isn't willing to cut me a break on the fix so it looks like I'm going to have to dig in.
oldnslo
Super Member
I can't tell from the pictures but are the ends of the pistons pitted or sand blasted looking? If yes this would be from cavitation which would point towards low or no charge pressure. Problem is some those little pieces of metal missing also went through the motor. Look very carefully at the port plate for any signs of scoring. Also check it for flatness. Check very carefully for any scoring between the kidney shaped ports on the rotating block also.
Roy
Roy
I did the oil leak test with the hydraulic gear pump as leonz recommended, filling it up with oil and looking for the leak rate on the back side. It was almost non-existant, with the oil coming through about 10-20 drops per minute so I think that's OK. Brought back visions on "days of thunder" when they looked at the wrecked car and said "hey, there's something that doesn't need to be fixed" and then robert duvall kicked it to make it perfectly ruined. Since it costs $600 I didn't smash the pump I just reinstalled it!
I also called bigorangeparts and the whole new HST was around $1400 (~10% lower than others I called). Jerkyboy, are you sure the bx1500 HST was only $500, that seems really low?
I also stopped by the dealership and they were amazed at the condition of the HST at such low hours. They put me in touch with the kubota tech support and they are opening a case file and customer support is supposed to call me. I'll keep you all posted.
I also called bigorangeparts and the whole new HST was around $1400 (~10% lower than others I called). Jerkyboy, are you sure the bx1500 HST was only $500, that seems really low?
I also stopped by the dealership and they were amazed at the condition of the HST at such low hours. They put me in touch with the kubota tech support and they are opening a case file and customer support is supposed to call me. I'll keep you all posted.
jerkyboy
Silver Member
Just got off the phone and they gave me a price for the wrong part, the HST is $1,220 (ouch!!!) and the cylinder block assemblies, which I'm assuming is what you had shown in your pic, are $187 each. When you say you paid $600 for the pump, which pump are you referring to and and where did you get it?
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I didn't buy anything yet. The gear pump that runs the implements, power steering and charges the HST was fine and doesn't need to by replaced, but looking at a few suppliers its $600 if it is toast. The HST itself is a hydraulic pump and motor. The price from bigorange was $630 for the pump that was shot in the picture I posted, or $1400 for the entire HST.
Also, to answer a previous question the image was blurry but the pistons themselves looked very clean with no pitting. I did see some very minor scratches on the surface below the HST pump and motor.
Also, to answer a previous question the image was blurry but the pistons themselves looked very clean with no pitting. I did see some very minor scratches on the surface below the HST pump and motor.
Well my opinion of Kubota took a further nose dive after talking with the factory rep, makes me wonder if they are following the chinese tractor model at Northern Tool, crank out some $%&^ with a one year warrantee and run, with the key exception of the price not being a good deal.
He told me he was really interested in seeing the transmission and helping me with my problem but that I needed to meet him at the dealer today. I drove 50 miles to bring the tranny in and he and the service manager met and agreed it was fried and it shouldn't have happened so early @ 500 hr. So he called me back later with a list of parts to replace, and an even bigger lists of excuses why he can't do anything.
The first was that I wasn't at the dealer I purchased it at which is only 800 miles from where I am now in NC. I asked him how that mattered and he couldn't tell me. Then it was that I had used the tractor in NY where it was cold and that can run down the tranny early in its lifespan. If HST's only last 500hr where its cold there's a problem. The next was that I did the work taking it apart so that makes it difficult to resolve. How? The HST is shot, I didn't round the pump bore by taking it apart? He then pointed to the zero turn mowers and said they have had a much higher failure rate and the BX's are only in the single digit % on early transmission failures so this is just an unfortunate dumb-luck fast-wearing one. That built some confidence. So if I want more peers to cry with buy a zero turn next time??
I wasn't looking for anything unrealistic, and even asked if they could at least just help with giving me a break on the cost of the parts. The answer was there is not anything he could do at all. He could have told me that before I wasted two hours and a long drive. PS, the HST costs almost 20% of the tractor's price new.
Well, I ordered the parts to do this myself, and will get it repaired, but I am not certain I will follow the orange path in the future. I was looking at an RTV over the next year but that is dead.
He told me he was really interested in seeing the transmission and helping me with my problem but that I needed to meet him at the dealer today. I drove 50 miles to bring the tranny in and he and the service manager met and agreed it was fried and it shouldn't have happened so early @ 500 hr. So he called me back later with a list of parts to replace, and an even bigger lists of excuses why he can't do anything.
The first was that I wasn't at the dealer I purchased it at which is only 800 miles from where I am now in NC. I asked him how that mattered and he couldn't tell me. Then it was that I had used the tractor in NY where it was cold and that can run down the tranny early in its lifespan. If HST's only last 500hr where its cold there's a problem. The next was that I did the work taking it apart so that makes it difficult to resolve. How? The HST is shot, I didn't round the pump bore by taking it apart? He then pointed to the zero turn mowers and said they have had a much higher failure rate and the BX's are only in the single digit % on early transmission failures so this is just an unfortunate dumb-luck fast-wearing one. That built some confidence. So if I want more peers to cry with buy a zero turn next time??
I wasn't looking for anything unrealistic, and even asked if they could at least just help with giving me a break on the cost of the parts. The answer was there is not anything he could do at all. He could have told me that before I wasted two hours and a long drive. PS, the HST costs almost 20% of the tractor's price new.
Well, I ordered the parts to do this myself, and will get it repaired, but I am not certain I will follow the orange path in the future. I was looking at an RTV over the next year but that is dead.
EE_Bota
Elite Member
I am sorry to hear that.
If I had agreed to meet with you, if I had to turn you down, I would have at least covered your trip, so you'd have gotten around $200 out of it.
jerkyboy
Silver Member
I second that. Looks like I'll be following the same path as you. So where did you end up buying the part(s) from and did you buy the HST or are you only replacing what's bad internally?
EE_Bota
Elite Member
I would look at all RTV's and make my best decision. The only person that could turn me off to an entire company is the owner of that company. If I wrote off every manufacturer of axial piston pumps whose pump failed prematurely, I would not have any pumps left.
People don't care if I turn my back on them. People care if I pursue them to the ends of the earth though. People don't care if I threaten them legally, though they frequently care if our corporate attournies threaten them legally. I'd tell the rep I value my trip at $200 bucks. I'd call or email him frequently.
Hello, have you sent me my $200 bucks yet.
It's snowy here, but pretty. Have you sent me my $200 bucks yet?
I hope you and your family are well. Have you sent me my $200 bucks yet?
Life it great here. Only $200 bucks would make it better.
Saw a nice pair of boots the other day. They were only $200 bucks. I wish I could have bought them.
I call it the "Aquaman" approach, demonstrated to me by a ME who we named "Aquaman."
The start of each day and the end of each day....he arrived with a smile, and asked "Have you had a chance to look into my request yet?"
"Nah...I am covered up."
"That's Ok!
I'll check back!" :laughing:And boy would he ever....
I'm just trying to let this one simmer down in my mind. Not worth having a stroke over it. I went home yesterday and cooled off by push mowing my lawn!! I just honestly don't see going through kubota in the future except for the overpriced superUDT2 fluid. There are others out there that are putting a lot more emphasis on customer service and I'll look at that.
I am replacing the entire HST. I just don't know what could have happened to the rest that I can't see and its too many hours to take it apart again and trouble shoot. I'll also put in new oil and change it out at 50hr like the break in period.
As a final note the one year warrantee really had me thinking last night to a bit of engineering advice I once heard (I am an engineer by training). It was you can predict how well something will work by how close the engineer is willing to stand next to it. If a lot of the car manufacturers can do a 4, 5, 10 ... year warrantee on a drivetrain, why can't a tractor manufacturer??
I am replacing the entire HST. I just don't know what could have happened to the rest that I can't see and its too many hours to take it apart again and trouble shoot. I'll also put in new oil and change it out at 50hr like the break in period.
As a final note the one year warrantee really had me thinking last night to a bit of engineering advice I once heard (I am an engineer by training). It was you can predict how well something will work by how close the engineer is willing to stand next to it. If a lot of the car manufacturers can do a 4, 5, 10 ... year warrantee on a drivetrain, why can't a tractor manufacturer??
EE_Bota
Elite Member
Matt, what branch of engineering, if you don't mind saying, and are allowed to say?
Replacing the entire HST would be the correct decision for me in my situation, with time, funding, amount of work, etc all considered.
I thought about suggesting replacing the entire HST, but it depends on funds, skills of digging into it, etc.
I'm a chemical engineer in the pharmaceutical industry. I did my undergrad studies in Agricultural and biological engineering (grad in chem engineering), and worked on farms and at Agway from middle school through college so had a good amount of experience fooling with equipment. The engineer in me justs loves understanding how things work, just not paying for them when they don't work! In pharmaceuticals equipment failure has a very large negative effect so I tend to sweat the details.
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