Kubota KX080 Quick Hitch

[Muz]

We have a couple of these machines that use the Miller Bug hitch, which is a variable centre hydraulic hitch, but from time to time the control ram inside the hitch fails due to the pounding that it gets.

When this failure happens, because its plumbed into the machines 'load sensing' circuit, (its only done this way on Kubota KX080 according to Miller ) it makes the machine do some odd things, in this case it prevented the dipper getting full power, but operated correctly in every other respect.

Heres it in operation

So once the ram is out its time to separate the end cap and see what weve got ?

You'll need your trusty 'C' spanner

IMG_1796.jpg .........

Have a good look round the head of the ram for any hidden grub screws .. this one has a nasty little 6mm fecker not easily visible unless you scratch the muck off first

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The arrow shows the location of the check valve on this cylinder which may need to be removed later to extract the rod and seal pack

Img_1790.jpg And here is the grub screw


So next I removed the check valve IMG_1791.jpg

And pulled the rod out to reveal the damaged seals

IMG_1792.jpgIMG_1793.jpg

Pretty messed up eh ? infact its just two components, an 'O' ring and a scraper type ring

[Muz]

Some engineers I have spoken to (and indeed Miller themselves) say that the cylinder can become slightly ovoid also, and could require checking with the appropriate guages to measure any distortion in the tube, because it may not reseal with new rings.

Here I've removed the rings with a new set 'A' ready to be fitted,.. the bearing strip 'B' looks serviceable

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My machine shop gave me the new rings which are harder wearing 'he said' but I'm not sure what they are made of, and require to be heated and then clamped with a circular clip prior ro reassembly.

As to costs, this ram was repaired for a tenner .. many just buy a new one from miller @ £350+VAT