New L185 developes hydraulic issue

Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
Well I am back to the site after some extended leave. I look after two elderly parents and last December my 93 year old mother fell in the night breaking her arm and because she was confined to a walker had to be put in rehab.... and a month later a series of strokes claimed her life. I had planed rebuilding the Z851 in my gray market L1801. The scheduled start date was January 1 .... and then my mother fell and that changed everything.

Was needing the L1801 with loader this year for market farming and other projects and so decided to pick up a 2wd L185 to use until I get L1801 rebuilt next winter.

So I find this nice clean almost one owner tractor with 866 hours and it even had the optional extra deep under-drive in it.... which I need when transplanting. Tractor came with a diy underbelly grader blade with 3 spool valve to operate 3 cylinders to independently raise and lower each side of the blade and to swing left and tight just like a real grader. Also came with a 5 foot 3ph flail mower which needs some repair. Got it with new battery for $1900 which was reasonable. Orange was repainted once and blue still factory and dry rotted original tires.

I have no need for the grader so I took it off and decided to take the quick attach Bush hog loader off of the L1801 and mount onto the L185.

So I examined the hydraulic system to understand how the diy grader blade units 3 spool valve had been combined into the system. The pressure hard line from the pump crossed over the tunnel just behind the tranny and there is a block mounted right on top of the tunnel (do not know if "tunnel" is correct nomenclature so correct me if I am wrong). There is a hard line exiting the block and connects to the rock shaft cylinder housing to supply that unit. On the side of the block there are fittings with soft lines attached.... those lines were pressure to and return from the 3 spool grader blade set-up. Those lines did not quick couple to the 3 spool valve but the quick attach loader I have is quick couple so I decided to to put quick couplings on the supply and return lines for easy hook up to loader valve which is a wobble stick.

This system is open center so..... oil must circulate through system constantly. So when I observed the block I wondered if the grader blade system and the 3ph system were in series .... OR was that block a divider valve. I assumed the block was a divider block and if so I would still have oil free flowing through through the 3ph system even though the grader/loader circuit would be closed when valve was removed !

Oops ... that assumption was a big mistake by this wannabe mechanic!!! Block was not a divider but just used to break into system .... so now I know the grader/loader system is in series with the 3ph system

:)

Tried to start tractor with quick couplers on lines but not attached to valve... tractor would chug chug chug and then stall !!!!!

Oil not free flowing through system ... so I go to local hydraulic shop and get fittings to connect two quick couplers end to end.

Get back home and connect the couplers and start tractor and I get chug chug chug and stall .... same symptom :mad:

So I take the quick coupler off of the supply line and start tractor ... it starts and runs normally as oil discharges from the line into a bucket.

So I get air hose and blow through the lines but there is a blockage ... so I break lines to locate blockage and find no blockage. Sooooo I put 3ph lever in down position dropping the lift arms .... hook up lines and put 3ph lever in "up" position .... then blow air into system and lift arms raise and then air ceases to flow through !!!!!!!!!!!!

Soooooooooooooooooooooooo now I must have developed a second problem ???

This tractor was bought new used on a five acre horse farm to clip pastures and maintain a long lane back to the farm house. Five years ago the original owner sold the property and the tractor went to a second owner who rented the o house and seldom used the tractor .... soo tractor may have sat idle for a long time.

Sooo help help help .... what is the problem ???

Maybe a valve stuck in the 3ph system ?

With 3ph lever in down position air will not blow through.... and I did remove the oil fill plug so air could pass out of the case without restriction.
 
Last edited:

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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Williamstown Ontario Canada
Rather than answer your question I am going to suggest some homework.

Go to this site and download a free Workshop manual for the L185.
Start reading at page 52 out of 63 pages total. This will help you understand the basics of the L185 hydraulic system including its position control.

http://kubotabooks.com/AutoIndex/index.php?dir=Tractor Owners Manuals/

From your photos I think you have the optional hydraulic block which was called a power beyond block by some. The L185 WSM dos not mention the optional hydraulic block

I have provided info from the B7100 WSM on the block because it likely is similar to the one you have.

When the 3 pt arms reach the top of their stroke, a feedback rod stops more pressure going to the lift arm piston. You should see this rod on likely the left lift arm.

Dave
 

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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
#1 STOP using air pressure to test anything on this system as it will do damage to valves, seals and such.

#2 Pull the block off and give detailed pictures of it.

I think I know what's going on but need to see the inside of the block to confirm this.
 

Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
OK thanks for advice .... will download and take off the block

and get back later

Gee so easy to get into trouble ... whowouldathunk

:)
 

Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
Well down loaded manual but did not read yet.

Took block apart and examined. I do not know what a divider or a power beyond looks like internally but I can tell you this is neither. I am a bit of a machinist and I can tell ya how it was made.... I am more of a machinist than hydraulics mechanic:)

The two halves were faced and circular grooves milled in them to support O rings. Holes were bored into each end of the rear half and two holes bored into the top of the front half and an additional hole drilled into the side for inspection or to drain. Holes were tapped for fittings. Smaller holes drilled into faced halves at center of grooved rings.

This block functions to ad another valve in series to the 3ph function.
 

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Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
Loader is on .... need to get problem fixed. I will be reading operators manual but I need to get this going asap
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
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Sandpoint, ID
From the side plug does the hole go through to the other side, that's why the side plug is normally in there.

Sometimes someone alters the original block and plus an internal plug in there to block the cross flow.

What you want is a path from port to port no matter how you have to make that happen. ;)
 

Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
From the side plug does the hole go through to the other side, that's why the side plug is normally in there.

Sometimes someone alters the original block and plus an internal plug in there to block the cross flow.

What you want is a path from port to port no matter how you have to make that happen.
;)

I examined it carefully but will re-check. If there is a path from port to port then oil will take path of least resistance and will not circulate through the auxiliary valve which in this case is the loader valve.

Dave directed me to a B7100 schematic of a power beyond. If you go there there is an original condition where the half block directs flow from port to port. Then in the second condition the half block is removed and replaced by a second block which he states is a power beyond. My block looks like that second condition..... but IMO that second block functions to put the auxillary valve in series with the 3ph valve.

I will recheck everything tomorrow but that side plug looks like there to drain the block and nothing else.

This tractor came with the 3 spool valve mounted on the tractor..... grader blade and three remote cylinders had been removed. Tractor was fine until I removed the 3 spool valve. The input and output lines were not quick coupled so I put couplers on and chug chug chug stall .... so I acquire fittings to make a connector to connect the two quick couplers together end to end and now oil should flow through just like it did when the 3 spool valve was attached. But start tractor and chug chug chug stall.

There was no problem until I removed the 3 spool valve and put quick couplers on the lines.... then there was a problem which was remedied by connecting the couplers end to end thus completing the flow through circuit... so that problem was solved but another problem evolved.
 
Last edited:

Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
Rather than answer your question I am going to suggest some homework.

Go to this site and download a free Workshop manual for the L185.
Start reading at page 52 out of 63 pages total. This will help you understand the basics of the L185 hydraulic system including its position control.

http://kubotabooks.com/AutoIndex/index.php?dir=Tractor Owners Manuals/

From your photos I think you have the optional hydraulic block which was called a power beyond block by some. The L185 WSM dos not mention the optional hydraulic block

I have provided info from the B7100 WSM on the block because it likely is similar to the one you have.

When the 3 pt arms reach the top of their stroke, a feedback rod stops more pressure going to the lift arm piston. You should see this rod on likely the left lift arm.
Dave

Yes mine has that adjustable rod and is similar to the JD 655 I have for sale.
 

Dave_eng

Well-known member
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Equipment
M7040, Nuffield 465
Oct 6, 2012
5,128
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Williamstown Ontario Canada
Yes mine has that adjustable rod and is similar to the JD 655 I have for sale.
Since the hydraulics worked fine with the three spool valve and grader blade and now is giving problems when you have installed a loader with its own valve, your mention of a JD655 makes me think....

Did this loader come from a JD? Perhaps not the 655 but another one.

John Deere often has closed center hydraulics. Such as valve will not work on your Kubota.

Dave
 

Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
Since the hydraulics worked fine with the three spool valve and grader blade and now is giving problems when you have installed a loader with its own valve, your mention of a JD655 makes me think....

Did this loader come from a JD? Perhaps not the 655 but another one.

John Deere often has closed center hydraulics. Such as valve will not work on your Kubota.

Dave
OK Dave I am reading your mind ... JD 655 loader is still on the 655. The 655 is open center..... But interestingly about 5 years ago I did buy a loader for my 1974 JD 830 utility tractor. It was a 147 JD loader off another model JD tractor ... Loader fits several models including mine and it mounted on with no trouble but Hydraulics had an issue similar to this one ....

My tractor had open center system but loader came from tractor that was closed system. Newer control valves can be converted to either open or closed by removing or inserting a plug but the valve on the loader was not convertible so I just bought a new Prince valve.

This Bush Hog loader was bought used and put on this L1801 by a previous owner who when head cracked sold to another man who had plans to fix but was diagnosed with prostate cancer so decided to sell tractor with mounted loader to me.

The L1801 does not have a hydraulic block so they removed about 12 inches of hard line and installed flared connectors and attached soft lines to each end and put quick couplers on ... If they removed the loader they would need to do as I did and connect quick couplers end to end or the system could not circulate. I think that they just mounted loader permanently.
 
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Kabota

Member

Equipment
Kabota L1801DT special
Nov 30, 2018
80
0
6
Summerville Pa.
So next I removed return soft line to the block and I took the fill cap off and inserted the return line into the tunnel case and started tractor. Hydraulic oil circulated into the sump. So moved the wobble stick and the loader was working against itself putting a load on the engine. Wobble valve is under a cover so I removed the cover and lines were on wrong. This valve input side is on the opposite side of the 3 spool valve that was on the tractor when I bought it.

So I fixed it .... then my soon to be 95 year old dad talked me into connecting the soft return line back into the block. Started tractor and hydraulic oil circulated normally and loader functioned normally

????????????????????????????????????????????????

Now I can not trouble shoot the problem since there is no problem.

But why would the system not circulate when I by passed the valve by connecting the quick couplers together end to end ?????

:confused: