JCB and my JCB 803 Driving Me Mad !

[AndrewMawson]

Mick you are an absolute star

[v8druid]

Something else that that I noted was on the early rotary joint both outer and inner parts were available separately, but on the later it's a unit! From an engineering point of view, maybe it points to the fact that they were not a very good machine fit and leaked by design! I will see what is available as far as drawings or such like material.

Mick

In theory Mick, if made to drawing, one could take any inner/outer off the shelf and mate them successfully, with the appropriate seals sets.

[Stock]

In theory Mick, if made to drawing, one could take any inner/outer off the shelf and mate them successfully, with the appropriate seals sets.

It's a jake, so it will be theory only master druid, nought interchangeable without lots of cash....................

[v8druid]

It's a jake, so it will be theory only master druid, nought interchangeable without lots of cash....................

Ain't that the truth, Stock!!

[Muz]

Interesting point .. youd expect the valve to be out sourced to some nippon supplier, but being jake they couldnt do that, so that only really leaves the frogs, the bosch, etc .. bound to be euro sourced

[v8druid]

Interesting point .. youd expect the valve to be out sourced to some nippon supplier, but being jake they couldnt do that, so that only really leaves the frogs, the bosch, etc .. bound to be euro sourced

If it were Nippon sourced Muz, there'd probably be a hell of a lot less issues and it'd fit no matter what.
They're great engineers, regardless of opinions.

[Muz]

They're great engineers, regardless of opinions.

Well my opinion is exactly that

[AndrewMawson]

Good News and Bad

Well with much assistance from Mick-the-Fitter by PM's - thanks Mick, and a bit of good luck the rotary seal issue is resolved

I went to site Monday to see what was happening, and while there JCB rang up to say they had located what the adapter kit was, but it would take 3 weeks to deliver it as bits had to be made Fortunately I was able to find a machine only 70 away in serial number terms that was being parted out, and the orbiter was still in it. The expensive new one went back to JCB and the s/h one arrived Tuesday, has been fitted and works

Now the bad news - the second spool block is leaking oil even in the relaxed state ie when no services are being used. It's about 7 segments and located in the most horribly inaccessible position, under the floor and under the seat. Leak seems to be from between the slices underneath (is this likely ??) on the neutral circuit rather than from the spools or their connections.

The parting out machine has already had this block removed and the only other one I've been able to locate has been well charred in a fire. So I've decided to have the block taken out and replace the slice seals, but before it's dismantled, to try and pressurise it and confirm the fault on the bench.

Does this sound a sensible approach?

Does anyone on the forum know of any 803's of this vintage being broken for parts?

[Muz]

Does this sound a sensible approach?

Its a bit impractical because you wont replicate the pressures that causes the problems when its not 'plumbed in' unless you really know your hydraulics ofcourse ? In most cases throwing a seal kit at it is the first approach, because , its not uncommon for certain types of seal to go 'hard' under cycles of heating and cooling, especially in .. ahem .. certain machines

Glad you got the O/V sorted for realistic money though I started this forum to help people resolve such matters without getting stung in exactly this way ... Good job to Mick too he got the bug .. innit fella ?

[AndrewMawson]

This is the beastly little thing

[Mick-the-fitter]

This is the beastly little thing

Hi Chaps, good news about the rotary valve, it sounds like old age is creeping into the machine, I agree with Muz, the place To start would be a reseal of the valve block, in theory a minor problem to fix. Easy for me to say!

Did you need part numbers for the seal kit?

Mick

[v8druid]

This is the beastly little thing

That's a real lil' futhamucker - do not envy having to extract that from there - lots of pix in order to suss the plumbing on the re-assembly and some marking up, with more pix!!
Can't imagine the slice seals are a huge task ......... just in need of care and patience on the re-assembly of teh block, I'd have thought
Keep us posted
Gra

[AndrewMawson]

Hi Mick good evening to you.

Are you talking essentially the 'o' rings between each slice or more than that ?

BTW for bench testing I have a small tank with oil immersed hand pump that'll go up to 1500 psi - plan was to blank off ports and pump oil into the P inputs (there are two on this block I believe) OK that's probably only about half what it runs at, but I'd expect the leak to show - but then I'm an optimist

[v8druid]

Hi Mick good evening to you.

Are you talking essentially the 'o' rings between each slice or more than that ?

BTW for bench testing I have a small tank with oil immersed hand pump that'll go up to 1500 psi - plan was to blank off ports and pump oil into the P inputs (there are two on this block I believe) OK that's probably only about half what it runs at, but I'd expect the leak to show - but then I'm an optimist

I'd be surprised if that didn't show up your leaks Andrew, with everything blanked off and that sort of pressure doing its damnedest to escape, any exit is going to be 'utilised' I'd have thought
Certainly worth a try

[Muz]

Yeah .. but ... the problem is.. even if you find the leaky one, by the time you pull it apart, you will doubtless disturb other potential trouble makers, so on a block of that age, you are as well doing the lot