Broke Hydrostat twice? Why?

[dfkrug]

BTW, please don't use "centigrade" for Celsius, that use was officially abandoned in 1948 due to disambiguity.

We did used to use those two terms synonymously for termperature in public school in the US. Tho now archaic, it is
still acceptable here. (As an aside, your countryman, Mr. Celsius, gets credit for the scale that bears his name, but his
scale used 0 for boiling and 100 for freezing.)

As a physics major in college, we mostly used Kelvin (SI) for temps, and varied between the 2 "metric" systems, M-K-s, and
c-g-s.

 

[TSO]

Sorry, phone made a duplicate

 

[TSO]

MHarryE ... Did you see my post/question regarding which HST oils you have found to be better able to maintain a lower temp, and also, in your experience with HST's, do you know which HST Massey uses in my 1648 (built by Iseki ?

 

[texasjohn]

Well Fluid,

The purpose of this thread is to determine how this happened.

If it turns out that the fault is inherent to the tractor, or TYM in general, then I'll have to agree with you although buying a new tractor has multiple issues for me.

But what if the damage is found to have been my fault- through ignorance or whatever? The tractor is otherwise perfect for me and with the kind of help I am finding here, I could easily change my habits. I know I can do this; I've been married 40 years.

Bob, I admire your attitude and approach!:thumbsup:

You approach things pragmatically and seek a fact based understanding of a situation.

Most importantly, you are willing to see several sides as a possibility and await actual data from broad ranging and science based study before reaching a conclusion for your situation. Further, you do not propose that your conclusion should be applied as the only conclusion to anybody else's problem.

Such restraint is a breath of fresh air which confronts the occasional and unwelcome swirling winds of dogmatic and ill advised commentary on TBN.

thank you and I look forward to your continued TBN posts. :yes::yes:

 

[Coyote machine]

Bob,
May I suggest you use your cell phone or digital camera with a card that is set/ adjusted to take pics in a size/format suited to uploading to TBN?
It can be done afterward, while sending them to TBN or otherwise, but sometimes it's easier to set up for JPEG or whatever you are going to use beforehand.
Hope you have a nice trip, and don't spend a lot of sightseeing time, we want answers, and loads of pics!

Thanks,

CM

 

[MHarryE]

MHarryE ... Did you see my post/question regarding which HST oils you have found to be better able to maintain a lower temp, and also, in your experience with HST's, do you know which HST Massey uses in my 1648 (built by Iseki ?

I have a lot of oil information but everything is dependent on the specific machine. Bob mentioned traveling to disassemble his hydro. The pictures of the failed hydro I showed were taken in Abu Dhabi. It was apparent the data we had collected in developing the machine in America didn't correlate well by extrapolating to the 40 - 50 Celsius operating on the Gulf so it was travel there, disassemble and analyze, then instrument 26 points in the system. Fantastic people to work with over there. Point out to them where I needed data, give them a supply of thermocouples, go out to dinner and my hotel and arrive the next morning to find they machined fittings to adapt my thermocouples so we could start gathering data. Then it was sit down with an engineer from our hydraulics supplier for that particular system and working with my lubricant specialist back home, come up with an immediate but temporary fix until engineering could resolve a hydraulic cooling problem. In this case it was 15W-40 engine oil because it was the only suitable oil available that wouldn't cause problems at cold startup yet provide a viscosity in the orange band on the chart I posted in the worst heat. Modern engine oils make very good general hydraulic oils but they are very expensive in the volumes used in a hydraulic system. In general synthetics are better than regular mineral oils. Synthetic blends are a compromise. It may be wrong but I assume other major companies have fluid specialists like my company and work with major oil company(ies) to develop oils suited for their product so our Deeres use Deere oil, Kubotas use Kubota oils, and New Holland uses New Holland oil. Then they end up being partially mixed when we swap implements between machines. I can't say the equipment my company left the factory with the best oil available. It left with the most economical oil that would do the job. If they were to leave with the best, they would all have a pure synthetic. I did have a few applications, one actually was a hydrostatic system, where a pure synthetic from one supplier was the only one that would really do the job.

To a previous post, I did mean 120 Celsius. I was referring to the motor case drain temperature, usually the hottest oil in a hydro circuit. This oil has just completed its job transferring power from the pump to the motor. At this point we use valving to draw a limited amount of hot oil from the loop and send it back to the cooler. This allows the charge pump to replenish the loop with cool oil.

All of the gear pumps I worked with have a 85C max operating temperature so our hydraulic oil warning alarms were set to 85C. Although our hydrostatics were all piston, they had gear pumps supplying hydraulic power to the auxiliaries and charge oil to the hydro.

 

[crazyal]

I would just say that while one of the biggest selling points for synthetic oils is cold temperature performance it has other advantages as well. If everything is working correctly then your hydro oil temps shouldn't get that hot. But if, as was mentioned, a spool valve was stuck in a position where it was causing fluid to open the pressure relief valve it could get well above normal operating temps. Another advantage of synthetics is that they resist thermal degradation (the ability of the oil to lubricate), resistance to oxidation (oxidation is what makes oil get thick from being heated over time), and has better film strength (clings to metal parts better).

An engine/ transmission may start off cold but most of it's use is at operating temps. While people always say that the most wear happens when an engine is cold that's only the case for an engine that is operating within the limits of the oil being used. If you are breaking down your oil with excessive heat then it's not going to protect your engine cold or at temp. I'm not saying synthetic will solve your problems or even be cost effective. Until we know what "broke" trying to solve the problem is kind of putting the cart before the horse. However a couple of steps can be taken to give the new HST the best possible chances to last a lifetime. One would be to pull a sample of the oil and regular intervals and have it analyzed. Another would be to change the fluid at shorter intervals (I would say synthetic would last twice as long as non-synthetic). I would suggest at maybe half what your manual states. Synthetic would be another way to help protect it. Another would be to prevent any spool valve from accidentally being pushed.

I know Chevron makes a synthetic tractor fluid. There was a dealer close by and the price was comparable to Kubota's super udt.

 

[Bob Christensen]

I haven't been here lately because we 've been getting ready for the road trip!

The oil question seems to have been answered for me for now anyway.

I was taking out logs from the woods with the grapple (thank you Island Tractor) when all of a sudden, the grapple stopped working. I didn't know what was happening, but I knew I had to GET OUT OF THE WOODS, so I dropped everything and tried to back out.

Then I lost all stearing. All I could think of was HST, AND THEN I LOST ALL POWER FRONT AND REVERS, confirming my worst fears. With all the things running through my head, my greatest concern was "How am I ever going to explain this to TBN. I mean three now. I'll just have to move and change my name.

It had gotten too dark for any examination,so I just crawled home and went to bed.

In the morning we went out to try an pull the tractor out to do I don't know what and there was hydraulic oil all under the tractor. Yup, a return line had been savaged by the wretched sticks. I can't remember ever having such relief.

Since I have a new replacement shoulder and a new replacement knee, until they heal, I'm not crawling around under any tractor ,especially in the woods.

So my wife did. With all those sticks and blackberries and 5 gallons of hydraulic oil, and she GOT that hose off.

I spent the next few hours running around trying to find a replacement, but it has a formed right angle and nobody had one, at least on a Saturday.
Last hope- the Jonn Dealer gave me a used radiator hose that looked about right, and my wife fitted it on using 4 hose clamps instead of two.

The debate about which hydro oil to use is now over for me, as I used the 5 gallon pail of Super UDT2 that I already had. No leaks and it's working perfectly again.

But anyone know if the radiator hose will last till the next oil change?

 

[jenkinsph]

I think I would keep the wife and sell the tractor. Never thought I would say that.:laughing:


When I started using tractors about 45 years ago I would drive them through the brush, sticks and low limbs. Today I keep my tractors out of those problem areas as much as possible, it simply costs too much in damage. I also used to get stuck in mud and make a mess, today I park my tractors and wait for it to dry up, less tractor problems and less damage to the ground.

 

[GManBart]

But anyone know if the radiator hose will last till the next oil change?

I wouldn't chance it. I'd take the damaged line to a local hydraulic shop and let them make you a replacement...shouldn't take long, or cost too much.

 

[Bob Christensen]

I think I would keep the wife and sell the tractor. Never thought I would say that.:laughing:


When I started using tractors about 45 years ago I would drive them through the brush, sticks and low limbs. Today I keep my tractors out of those problem areas as much as possible, it simply costs too much in damage. I also used to get stuck in mud and make a mess, today I park my tractors and wait for it to dry up, less tractor problems and less damage to the ground.

Yeah, you're right, but I was in such a hurry... Sometimes I think I'll never grow up

 

[Bob Christensen]

I wouldn't chance it. I'd take the damaged line to a local hydraulic shop and let them make you a replacement...shouldn't take long, or cost too much.

The thing is, one of the places I went to WAS a hydraulic shop, and they couldn'tt do it.
I can order the hose from Jordan, my dealer, and have it ready when I get back, but aside from the cost of the (factory) hose, i wouldn't trust myself to dump 5 gallons of SUDT2 catch it all and get it back in clean.

I might try that with an engine, but for some reason, I'm a bit gun shy with hydrostat.

 

[dfkrug]

So my wife did. With all those sticks and blackberries and 5 gallons of hydraulic oil, and she GOT that hose off.

.
.
.

But anyone know if the radiator hose will last till the next oil change?

Wow, Bob, is she gonna put the new hose on, too?

Rad hoses don't do well with oil, and hot oil has gotta be worse. I once used a rad
hose for my diesel fueling tank, but went and got the correct one eventually. Since
the replacement interval for hyd oil is 400hr or so, you won't want to wait that long.

Sorry about the mishap...see ya next week.

 

[Bob Christensen]

Wow, Bob, is she gonna put the new hose on, too?

Rad hoses don't do well with oil, and hot oil has gotta be worse. I once used a rad
hose for my diesel fueling tank, but went and got the correct one eventually. Since
the replacement interval for hyd oil is 400hr or so, you won't want to wait that long.

Sorry about the mishap...see ya next week.

Well, she already put the new, used John Deere rad hose on, but when I get a real new hose , I'll have access to a floor jack, cement floor and a creeper, so I suppose she'll insist on me doing it. I mean it's not like she spoils me or anything.

 

[dfkrug]

Well, Bob and Susanne stopped by yesterday, and we looked at the innards of his HST.
I will post this weekend on the results.

We had a very nice visit.

 

[dfkrug]

At first examination, this unit is similar in size to HSTs on my B21 and JD955s. There
is no integral charge pump, and the swash plate speed pump control is mechanically
linked to the go-pedal.

After splitting the case, I first removed the motor (1st, 2nd photos). On first inspection, it
looked OK. The slippers looked smoother than I am used to seeing. Other HSTs
have pre-cut scratches in the slippers to help retain an oil film. I will check the
thickness with a micrometer later, after getting the spec from the manual. All
pistons moved easily in their bores, without any noticable excess clearance.

The fixed swash plate was smooth and completely free of scratches. The valve
plate was slightly scored, failing the fingernail test. Hard to see in our photos.
Not our "smoking gun", however.

 

[Leejohn]

I have been waiting and glad he got it to you. This well be interesting.

 

[Coyote machine]

So that's not the smoking gun- do you know what is, or are we 'gonna have to send some people down from the East coast? Ya know what I mean?:laughing:

 

[dfkrug]

So that's not the smoking gun- do you know what is, or are we 'gonna have to
send some people down from the East coast?

Patience, Grasshopper.

You know how I like to drag these stories out.

 

[dfkrug]

Here are some close-ups of the motor valve plate. It is clearly scored, and that is
not good, but it still worked in reverse.