Husco Hydraulic Detent Replament and Fix on a Kubota B7800

[Hodgy]

On my 06’ Kubota B7800 the float detent on the HUSCO hydraulic valve got damaged by ice in the cap that had no way to drain out. This is a known defect on these valves as rain and melting snow runs down the valve body and seeps into 4 gaps between the collar, spacers and cap. When I took off the caps, both were 2/3 full of ice with some rust to the interior parts, dented and broken ball bearing housing, crushed spring and flattened ball bearings. HUSCO provide their valves to Kubota on a proprietary basis so you cannot buy directly from them. Kubota do not sell separate parts for this assembly and you have to buy the complete kit for $161.42 CAD. The Detent/Float kit is #7553665400 and the Detent/Regen kit is #7553665100 and is $169.11 CAD. The only difference between the two is the inside profile of the “barrel” that the ball bearing housing fits into.

The fix for this trapped water problem is to drill a drain hole in the bottom of the cap and another at the top of the aluminum collar so the water drains out and you can spray WD-40 in the top hole to flush out any moisture.


The idea to drill holes in the cap and collar are not mine but a member from here “Butch”. He made comments on many posts and even provided photos of where to drill the holes. I decided to make a how-to video to help others.

If you have HUSCO valves on your Bota’, do yourself a favour and drill holes in the caps. You might be surprised how much rust is in there. If you are going to disassemble, remember the 5 ball bearings in there are under spring tension.


Here is a video I made yesterday, grab a coffee its 15 minutes long.

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[lugbolt]

there is a kit to fix it and the kit has a drain in it that don't require drilling no hole, there's a slot between the cap and spacer to allow moisture to drain out

however it doesn't seem to matter, because in another 20 years, moisture from the air will still cause corrosion again

 

[Hodgy]

there is a kit to fix it and the kit has a drain in it that don't require drilling no hole, there's a slot between the cap and spacer to allow moisture to drain out

however it doesn't seem to matter, because in another 20 years, moisture from the air will still cause corrosion again

So how does that work ? There are already two slots on the cap next to the spacer and the angle that the valve body is mounted still makes the end of the cap the lowest point for water to drain into.

Hodgy

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[GeoHorn]

So how does that work ? There are already two slots on the cap next to the spacer and the angle that the valve body is mounted still makes the end of the cap the lowest point for water to drain into.

Hodgy

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You are asking him how a defective design cannot work? The results pretty much tell the tale. The slots don’t work...and water still gets into the bottom and can freeze.
(I suspect the slots are not for water ingress/egress purposes. The slots are likely to allow air to flow in/out, since the hydraulic seals/o-rings would normally seal against that and deform without those vents.
(IF water is sitting at the top-slot/vent and the float-lever is allowed to move upward it will SUCK that water into the lower chamber. That’s what I believe is happening.)

Nice effort to help others, Hodgy!

 

[chim]

Sounds like the trouble I had with the B7500 joystick years ago. I remember being able to get it cleaned up and working. I did lose one of the balls in the garage. Fortunately there’s a REAL hardware store not too far away. I was able to take a sample and a caliper and get a replacement.

 

[Hodgy]

I did a modification to keep the rain and snow off the valve body when the Bota' is sitting.

 

[Butch]

Mine screwed up also... the design sucked so to remedy the issue (after cleaning and valve reassembly) I drilled two 1/16" holes in each valve cover. One at the top and one at the lowest point on the lower end. As part of my maintenance routine I shoot WD40 in the top hole and flush it. No more water problems.

 

[Hodgy]

Mine screwed up also... the design sucked so to remedy the issue (after cleaning and valve reassembly) I drilled two 1/16" holes in each valve cover. One at the top and one at the lowest point on the lower end. As part of my maintenance routine I shoot WD40 in the top hole and flush it. No more water problems.

Thanks Butch it was your post that pointed me in the correct direction. I thought I would make the video to show others how to fix the problem. Definite design flaw on HUSCO's part.

 

[Hodgy]

Here is the schematic of the detent kit.