HST pressure tester?

[BAP]

You seem bent on going right to buying expensive diagnostic equipment without doing the simple stuff first. Check clutch and changing filters should be the number 1 priority. Doing high dollar pressure testing is a complete waste of time and money if the clutch is bad and/or the filters are plugged up.

 

[lightning337]

You seem bent on going right to buying expensive diagnostic equipment without doing the simple stuff first. Check clutch and changing filters should be the number 1 priority. Doing high dollar pressure testing is a complete waste of time and money if the clutch is bad and/or the filters are plugged up.

Not bent. Just being prepared. Will do the clutch tests when I get home this evening.

 

[TheOldHokie]

Not bent. Just being prepared. Will do the clutch tests when I get home this evening.

In any event it does not require big bucks:

OHI-G-2.5-10K-S : OneHydraulics 2.5 Face Pressure Gauge, 0-10,000psi Pressure Range, 1/4 NPT, Stem Mounted Style

The OneHydraulics OHI-G Series Gauges are Glycerine filled, and feature a 304 Stainless Steel Case and Bezel with phosphor Bronze Bourdon Tube, Bronze Connection, and Polycarbonate Lens. This gauge features a built-in snubber, and the display offers both psi and bar readings with a scale up to...

www.onehydraulics.com

Dan

 

[PoTreeBoy]

In any event it does not require big bucks:

OHI-G-2.5-10K-S : OneHydraulics 2.5 Face Pressure Gauge, 0-10,000psi Pressure Range, 1/4 NPT, Stem Mounted Style

The OneHydraulics OHI-G Series Gauges are Glycerine filled, and feature a 304 Stainless Steel Case and Bezel with phosphor Bronze Bourdon Tube, Bronze Connection, and Polycarbonate Lens. This gauge features a built-in snubber, and the display offers both psi and bar readings with a scale up to...

www.onehydraulics.com

Dan

Dan, since you're here, let me ask you a coupl'a questions. In OP's post #5, the adapter called for on the charge pressure is PT1/4. But it calls for an o-ring on the plug. Would a 1/4 BSPP be the appropriate adapter? And for the high pressure, a PS3/8 is called for. Would 3/8 BSPP be correct?

 

[lightning337]

https://a.co/d/08pVKcZ

May look to buy this pressure testing kit of it's not the clutch.

 

[TheOldHokie]

Dan, since you're here, let me ask you a coupl'a questions. In OP's post #5, the adapter called for on the charge pressure is PT1/4. But it calls for an o-ring on the plug. Would a 1/4 BSPP be the appropriate adapter? And for the high pressure, a PS3/8 is called for. Would 3/8 BSPP be correct?

[GEEKMODE]

PT and PS are the (very) old JIS designations for BSP. JIS now uses the ISO designations.

PT = BSPT = R thread
PS = BSPP = G thread

The JIS/ISO/BSP standard allows using a male taper fitting in a female parallel port.

[/GEEKMODE]

So to answer your question it sounds like both port are G thread and the factory plug is also G thread with oring. The test fitting for one is R thread without oring and G thread with oring for the other.

Thats my best guess. I will also note rhat Kubota often calls out sealing washers as orings.

Dan

 

[TheOldHokie]

https://a.co/d/08pVKcZ

View attachment 155348

May look to buy this pressure testing kit of it's not the clutch.

A worthwile addition to any tractor owners toolbox.

Dan

 

[lightning337]

Okay guys, I may have a verdict. Couldn't get the tractor to stall in medium range, revs up, pedal full forward, brakes fully pressed. The revs didn't dip once.

Clutch gotta be burned up.

The tractor supposedly has 1380h on it. But it looks like all very hard hours as it's pretty beat up.

I find it weird how in high and low range, the tractor won't move. But medium range I can get it to limp along.

But the pto still engages even in high gear.

Am I doing something wrong? Any other tests I can run on the clutch?

 

[TheOldHokie]

Okay guys, I may have a verdict. Couldn't get the tractor to stall in medium range, revs up, pedal full forward, brakes fully pressed. The revs didn't dip once.

Clutch gotta be burned up.

The tractor supposedly has 1380h on it. But it looks like all very hard hours as it's pretty beat up.

I find it weird how in high and low range, the tractor won't move. But medium range I can get it to limp along.

But the pto still engages even in high gear.

Am I doing something wrong? Any other tests I can run on the clutch?

You shuld be ablr to stall it in medium range. Put the nose against a big tree and try again. Then repeat in low and high.

Dab

 

[lightning337]

You shuld be ablr to stall it in medium range. Put the nose against a big tree and try again. Then repeat in low and high.

Dab

It's raining right now but I'll be sure to give that a try once it's dry out.

When I had the backhoe and loader on, they both felt to have good power when operating them. I didn't have them on long as both were leaking at nearly all cylinders so I took them off. I didn't put them under any load but their functions seemed fluid and good.

I'm already anticipating splitting this tractor so I've started stripping it down so it can fit into my small garage.

 

[TheOldHokie]

It's raining right now but I'll be sure to give that a try once it's dry out.

When I had the backhoe and loader on, they both felt to have good power when operating them. I didn't have them on long as both were leaking at nearly all cylinders so I took them off. I didn't put them under any load but their functions seemed fluid and good.

I'm already anticipating splitting this tractor so I've started stripping it down so it can fit into my small garage.

View attachment 155369

I dont know that machine well but I think the backhoe and loader pumps have nothing to do with the HST.

Kubota likes to use the PS pump return as the source for charge pressure and the HST is its own pump.

Dan

 

[lightning337]

I dont know that machine well but I think the backhoe and loader pumps have nothing to do with the HST.

Kubota likes to use the PS pump return as the source for charge pressure and the HST is its own pump.

Dan

I'm sure you are right from briefly scanning the WSM.

Fingers crossed my hst is fine. Checked Messicks and an HST is now over $7000!!!

 

[PoTreeBoy]

I don't know that machine well but I think the backhoe and loader pumps have nothing to do with the HST.

Kubota likes to use the PS pump return as the source for charge pressure and the HST is its own pump.

Dan

According to the diagram lightning posted, this machine has a separate charge pump in the HST unit. It is kind of connected to the PS discharge (I think that's a check valve)?

 

[PoTreeBoy]

It's raining right now but I'll be sure to give that a try once it's dry out.

When I had the backhoe and loader on, they both felt to have good power when operating them. I didn't have them on long as both were leaking at nearly all cylinders so I took them off. I didn't put them under any load but their functions seemed fluid and good.

I'm already anticipating splitting this tractor so I've started stripping it down so it can fit into my small garage.

View attachment 155369

I wouldn't strip it too far. Unlike some models, it looks like all 3 valves can be serviced from the outside. Of course, the problem could be something else. Actually, there may be a fourth valve.

 

[PoTreeBoy]

Okay guys, I may have a verdict. Couldn't get the tractor to stall in medium range, revs up, pedal full forward, brakes fully pressed. The revs didn't dip once.

We may have a misunderstanding. By 'stall' I don't mean the engine stalls. I mean the wheels quit pulling.

With the brakes pressed, high range, pedal forward, the engine kept running, did the wheels stop? At that point did the PTO keep turning?

 

[TheOldHokie]

According to the diagram lightning posted, this machine has a separate charge pump in the HST unit. It is kind of connected to the PS discharge (I think that's a check valve)?

Could be there is an internal charge pump fed by the PS return. HSTs are not my strength and I dont know the details of how Kubota designed that.

But my point remains the loader and hoe hydraulics are unrelated to the HST.

Dan

 

[lightning337]

We may have a misunderstanding. By 'stall' I don't mean the engine stalls. I mean the wheels quit pulling.

With the brakes pressed, high range, pedal forward, the engine kept running, did the wheels stop? At that point did the PTO keep turning?

Lol misunderstanding for sure! I'm not afraid to say I'm a tractor newbie. That's why I'm here to seek advice and learn.

Here I am thinking it'd stall like a manual car or like my massey 35! Haha.

I will try tomorrow as we got rained on today.

This HST is a different animal. I'll try the tree technique like hokie suggested and I'll try the high range and pto again. I'm not confident on the high range moving the tractor as it doesn't. But I'll try to see if the pto moves while performing your steps.

 

[lightning337]

Thoughts? Advice? Clutch any good? I'm leaning towards a pressure issue...

Please advise this tractor newbie. Thanks!

 

[PoTreeBoy]

Thoughts? Advice? Clutch any good? I'm leaning towards a pressure issue...

Please advise this tractor newbie. Thanks!

I couldn't understand all you said, but I think you had it in high range, pushed the pedal, and it barely tried to move. The PTO continued to rotate at the same speed. Right? If so, we've ruled out the clutch.

Now on to the logic diagram in your post #1. As the diagram directs, test the charge pressure first. Since both forward and reverse are affected, the charge pressure is common to both.

You have checked your fluid level, correct?

 

[lightning337]

I couldn't understand all you said, but I think you had it in high range, pushed the pedal, and it barely tried to move. The PTO continued to rotate at the same speed. Right? If so, we've ruled out the clutch.

Now on to the logic diagram in your post #1. As the diagram directs, test the charge pressure first. Since both forward and reverse are affected, the charge pressure is common to both.

You have checked your fluid level, correct?

Thanks for reviewing my video!

Yes, I feel the clutch is still good.

Correct, I put it in HIGH range with PTO engaged. Pretty much did a brake stand and no effect on the PTO. Rotated as normal.

I guess I'm onto HST pressures now.

Well, I still have travel, right? I can still limp the tractor around- both forward and reverse.

I think I'm going to take a chance on that amazon pressure testing kit I posted earlier with the 5 gauges and numerous fittings.