ZD326 Lift Wiper Seal Will Not Go In

Mr Haney

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L3710, ZD326S
May 23, 2022
422
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The lift cylinder on my ZD326 died. I found info on this forum:

Outer wiper seal 40-48-5, inner seal 40-48-5.7.
I ordered the seals from Hercules. Today I managed to get the cylinder apart, and the old seals were like cheese. The wiper came out in tiny bits, and the other seal was not much better off.

The inner seal went right in. I used a cheap seal-bending tool. The wiper refuses to work. It took me forever to get the outer edge into the groove, and I ended up unable to get a lot of it in, so now I have a big wave I can't push in. It's like the outer circumference is too big.

Clues would be appreciated. I can't believe those seals were working a month ago.
 

Killer Bee

Active member
May 15, 2026
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for small cylinders like that you almost need superhuman fingertip strength. :D

make sure grooves are completely clean and absolutely nothing left from old packing or any dirt or debris is left in them. I use plastic dental picks to clean corners of the grooves and inspect with small round dental mirror.

also make sure packings are correct size, arranged properly, and installed in proper sequence. warm water may help make pfte, teflon, du, etc. more pliable. tapered installation tools also help.

and don't forget lube and even pressure during final assembly so packing doesn't get cut or damaged. keep rod, piston, gland, etc. properly aligned, no cocky-cocky during assembly. ;)

here's a little info on how the pros do it. good luck! 🍻


 

Mr Haney

Active member

Equipment
L3710, ZD326S
May 23, 2022
422
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43
FL
I appreciate the help.

I have done all the obvious stuff. Today I soaked the seal in 150-degree water for three minutes, and it made no difference at all.
 

Mr Haney

Active member

Equipment
L3710, ZD326S
May 23, 2022
422
116
43
FL
Turns out the wiper was too tall. I needed to go to the hydraulic shop anyway, so I took the cylinder. They confirmed that 40x48x5.7, which I got from a forum post here, was not going to work. They installed a 40x48x4.

To be clear, it looks like I got the wiper and inner seal heights confused. The 5.7 measurement was actually for the inner seal. Oops.

CORRECTION: I have double-checked, and I did not confuse the seals when ordering. I got what was recommended, but the shop confirmed that the 40x48x5 wiper was too tall. I got the idea that it was a 5.7 from trying to measure it with calipers.

To sum up, the MRU-40X48X5.7-E inner seal I bought does fit, the MSW-40X48X5 I bought did not fit and was ruled out by the hydraulic shop, and the MSWS-40x48x4 the shop installed should work.
 
Last edited:

Killer Bee

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May 15, 2026
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does kubota not carry the proper cylinder packing for your machine serial number? there's some times it's just hard to beat oem. sounds like this might be one of them. and a valuable lesson to those following along. ;)

so did the shop not assemble and test it for you after recommending a different size?

if not and you're assmbling at home, at a minimum I would air test it before installing into the machine. especially based on all the confusion over proper packing sizes.

good luck! 🍻
 

Mr Haney

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Equipment
L3710, ZD326S
May 23, 2022
422
116
43
FL
Thanks for the response.

I think this site needs a thread of Kubota seal cross-references, because this is an area where they REALLY put the screws to people, and they do not publish specs. A lot of their parts are very reasonable, but seals are nuts.

The OEM seals are clearly nothing special, because mine turned into crumbs in 19 years (probably more like 10), with Kubota fluid.

Kubota cost: $135, including shipping, for two seals. My total cost, after paying a shop and buying my own seals: around $50. Cost to me if I had known what I was doing: about $25, total, tax and shipping included. If I lived close to Hercules, my cost would have been maybe $15.

I'm no socialist, but charging that much for two Kubota-packaged seals is insane. Kubota's cost for the seal kit is probably less than $10. I would be amazed if a dealer pays $20. Kubota can definitely do better.

I don't know if the shop tested anything, but a wiper is pretty simple, so I'm not worried. It doesn't encounter any pressure. If it fits and pushes dirt away, it should be okay. I believe the inner seal is the right size, and I tried to choose the best quality. Hoping for the best.
 

Killer Bee

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May 15, 2026
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hmm, a dedicated sub forum with (verified) cross-reference data could prove very helpful.

at several places I worked, we had custom seal kits made for fast moving parts we went through frequently.

AC DePuydt, MFCP, Motion, Applied, etc. made custom seal kits from verified oem samples or good used that were measurable. they use their premium seal component part numbers for a bom (bill of materials) and assign a custom part number for our kits.

forklifts, wheel loaders, track hoes, pitman cranes, you name it. locally sourced, fast delivery, oem or equivalent quality, almost always less expensive = no brainer.

I'm new here so I have no idea how many folks it would reach. but for those that need kits, priceless. I only have 4 orange machines but happy to contribute where possible.

parts sourcing and accuracy can definitely be extremely stressful, why I suggested oem for one-off situation (although I was not aware of drastic price difference). glad your dilemma worked out! 🍻
 

Mr Haney

Active member

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L3710, ZD326S
May 23, 2022
422
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FL
The sad thing is that I relied on someone here who tried to help, and the seal he recommended did not go in. I don't know a whole lot about seals. I would guess that any 5 mm seal fits like any other, but the one I bought was unquestionably impossible to use.
 

whitetiger

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Kubota's cost for the seal kit is probably less than $10. I would be amazed if a dealer pays $20.
When a manufacture signs a contract with the supplier of a cylinder, valve etc, to use their component, the replacement parts prices are included.
Kubota cannot go shopping for generic service parts to sell, and Kubota's mark up to the dealer is approximately the same as any other part.

The dealer has some leeway on their retail price.

Your dealer is paying way more than $20.00 for the seal kit.
 
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Mr Haney

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L3710, ZD326S
May 23, 2022
422
116
43
FL
How can the markup for a seal be the same as a markup for, say, a battery cover? That is amazing. I would expect to pay $20-$35 for any steel part similar to a Kubota battery cover, even at Harbor Freight, and that's what the Kubota part costs, but a set of seals I can get for $10 costs $116.50 from a Kubota dealer. A lot of their parts aren't overpriced at all, so this seems odd to me. If it isn't gouging, what is the accounting quirk that explains this?

The battery cover, which I actually have, is very reasonably priced, and I know very well that the cost to Kubota isn't dramatically less than the seal kit cost. I also priced a muffler and a grille for a tractor, and I thought Kubota was not out of line at all. On the other hand, charging several dollars for a below-average Kubota-packaged nylon push pin, which adds right up when you need 30 of them, is silly. I bought a whole bag of better pins for the cost of a couple of the Kubota parts.

Is Kubota telling dealers they can't buy aftermarket seals? I know some dealers sell hydraulic fluids other than UDT and UDT2, so I have to wonder.

I don't understand why Kubota would make no effort to get decent prices on seals. If I were building tractors, and a supplier told me it wanted dozens of dollars for a $2 seal, I would look for a better deal. The whole cylinder, including seals, runs about $460 retail, and if what you're saying is true, the cost of the seals is behind over 20% of that.

Bigger cylinders routinely sell for about $100, and Kubota has used a zillion of these lift cylinders, so I don't think they can reasonably complain that it's an expensive custom part with a limited run.

As for the fluid, I don't get it at all. Unless I am mistaken, other tractors last just as long and do exactly the same things, using fluid that costs half as much. I don't have any idea why Kubota would make machinery that malfunctions and falls apart on cheaper fluid other machines use with no problem. Maybe they have a great reason.

A.I. says Kubota's pricing for the seals is "captive market" pricing, which basically means "gouging." It refers to parts that are very important, which most consumers will not source elsewhere because of the aggravation. In other words, "We charge a lot because we can." Is that incorrect?

A.I. thinks the seals will almost certainly fail two to three times in the 4000-hour life of a mower, so if that is right, it seems like they made the seals expensive in order to guarantee themselves some seal profits and give dealers two to three big repair bills. Based on the difficulty I had replacing my seals, and assuming a dealer is much faster, I would expect to pay for at least one hour of labor every time, so add that to the $116.50. Adds right up.
 

whitetiger

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How can the markup for a seal be the same as a markup for, say, a battery cover?
The dealer markup percentage does not care what the part is; if they are using a 30% mark up, it is pretty much the same across all parts.

Kubota buys parts from a manufacturer or supplier, and they have a markup. Kubota then sells the part to their dealers after adding a markup. The dealer sells those parts to their customers and also marks up the price.
Everyone who handles the part adds a markup.


Is Kubota telling dealers they can't buy aftermarket seals?
There is a signed, legally binding charter between Kubota ( any manufacture realy) and a dealer as to sales, parts, business practices, handling of warranty, etc. I have not read a charter, so I do not know the exact wherefores and such.

As far as A.I. results, you may as well ask your neighbor's bulldog for his opinion.
 
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PoTreeBoy

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Is Kubota telling dealers they can't buy aftermarket seals? I know some dealers sell hydraulic fluids other than UDT and UDT2, so I have to wonder.
I'd be surprised if the agreement between Kubota and its dealers allowed the dealer to sell off-brand parts. Same with auto dealers, I suspect.
 

Mr Haney

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L3710, ZD326S
May 23, 2022
422
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FL
Kubota needs to negotiate a little harder with those seal factories in China!

Anyway, it would be great to have a thread for this. Hercules has a list, but it's incomplete.
 

PoTreeBoy

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Kubota needs to negotiate a little harder with those seal factories in China!

Anyway, it would be great to have a thread for this. Hercules has a list, but it's incomplete.
I've had the NLA (no longer available) issue on hoses, and posted dimensions on several in this section.

As for cylinders, I repaired the first couple myself, when the Kubota kits were more reasonable. But lately, I just take the cylinder to a shop 20 miles away. For ~$100 he does material and labor. If I had the dimensions or part numbers before taking them apart so I could have the parts on hand, I might do it myself again.
 

JasonW

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Jan 29, 2015
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To follow up on this are the parts listed in post #4 correct? You stated they were installed and should work. Seen where you ended up with a new mower.

The cylinder on my ZD331 started leaking pretty bad suddenly. Got it removed and apart and the seals basically disintegrated. Went by a few “hydraulic shops” and none carried any seals on stock.
 

Mr Haney

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L3710, ZD326S
May 23, 2022
422
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FL
Sorry you're having trouble with your cylinder. As far as I know, whatever I said in post 4 is right. I have not gotten rid of the mower yet, and the deck is going up and down just fine. I have not checked for leaks, but there is no reason why there should be any. No oil has appeared on the concrete.

I didn't get the new mower because the old one isn't working. It's working great. I got it because I don't trust it to continue working, and I don't want to keep wasting family time on surprise repairs that take hours or days.
 
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whitetiger

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I'm no socialist, but charging that much for two Kubota-packaged seals is insane. Kubota's cost for the seal kit is probably less than $10. I would be amazed if a dealer pays $20. Kubota can definitely do better.
Dealer cost would be near $90.00, and that's a fact.
 

Workerbee

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This is back in time a ways, but when farming we ran Allis Chalmers Gleaner combines. Parts would always be much higher than similar John Deere or IHC parts. I knew a guy well who worked in Agco’s parts dept in the caves by Kansas City. I asked him why that was that way. He told me that they typically marked parts up 7x cost. It took a tremendous amount of money to operate their parts system, especially being world wide, so the whole markup certainly wasnt profit. How much was? He didn’t say, but I would guess maybe 10-20% after alls said and done. If it was much more, aftermarket would eat their cake.
 

Killer Bee

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This is back in time a ways, but when farming we ran Allis Chalmers Gleaner combines. Parts would always be much higher than similar John Deere or IHC parts. I knew a guy well who worked in Agco’s parts dept in the caves by Kansas City. I asked him why that was that way. He told me that they typically marked parts up 7x cost. It took a tremendous amount of money to operate their parts system, especially being world wide, so the whole markup certainly wasnt profit. How much was? He didn’t say, but I would guess maybe 10-20% after alls said and done. If it was much more, aftermarket would eat their cake.
my dad was a main frame welder at the independence plant 37 years until it closed in 2000 and moved to hesston and he begrudgingly retired.

our 1964 model E made the first year he worked there.

 
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