JCB 803 Saga

[awemawson]

About five weeks ago I bought a 17 year old JCB 803 3 ton mini-digger which has given me a bit of grief 

Having had a brand new engine fitted 200 hours before I got it, at least that area was sound, but the day after I got it, it developed a massive oil leak dripping from the area of one of the track motors. A bit of investigation showed that in fact the oil was leaking from the 'Orbiter', and running down into the lower chassis and exiting by the track motor. The Orbiter is a rotary hydraulic coupling that takes ten hydraulic lines from the cab and super-structure that rotates 360 degrees, down to the track chassis to feed the tracks and dozer blade.

I decided I was too long in the tooth to be crawling about in and under, so packed it off to a local (ish) commercial garage to fit a new set of seals in the orbiter. Seals duly arrived from JCB - chap fitted them and the blasted thing leaked worse than ever  I reluctantly authorised buying a brand new one. New one needs a conversion kit say JCB as there's been a design change - all in not much change out of £1000 

I went to see progress on Monday to find JCB not only were not able to supply the conversion kit, they had no drawings of what it consisted  While I was on site they rang up to say that at last they'd found a drawing and it would be a further 3 weeks for them to make it 

Time for a bit of research  I tracked down a breaker hundreds of miles away who had an 803 only 70 different in serial numbers, and yes it still had the orbiter and it was mine delivered overnight for £230 - a result. I took it to the garage yesterday and await results  The £1K one has gone back 

[awemawson]

Now while this machine has been away I've been trying to source it's right hand servo control lever - just a two part plastic moulding as a hand grip - it contains also one button for the horn. Previous owner had broken / lost / been vandalised and had fixed a length of plastic pipe on instead.

JCB were happy to provide me with a handle for £180  and that didn't include the micro-switch for the horn, or the special rubber grommet that you press as a button to operate it - yes button thing available for £34 plus VAT !!!

Now initially my new friend the machine breaker was reluctant to part a handle from it's servo control, but a bit of sweet talking liberated what looked to be a bit of a grotty version, taped together with Elastoplast and missing switch and button for £20 - but beggars can't be choosers - no one else had one to break! Surely I can fix it. It even came with it's rubber gaiter (that was slowly falling apart) thrown in.

[awemawson]

When it arrived, in fact it was far better than it had looked. The micro-switch and cable form were in place, just the button missing 

A quick bit of cleaning up and the handle is perfectly serviceable - even the gaiter was glueable using some magic stuff intended for fixing tears in welly boots. So what about that special grommet / button jobby?

The original was a domed 9 mm blanking grommet that had an extra rubber protrusion downwards from the centre of the dome to operate the micro-switch. I had some domed 9 mm grommets in stock - and tried gluing rubber cord to the under dome, but they were not flexible enough.

Then I thought, all it really needs is a piece of (say) 8 mm rubber cord retained in the handle hole - so a sort of dumb bell or diablo shape whose inner part is 8 mm and outer is 9 mm

Time to make a mould and get out the hot melt glue gun

[awemawson]

Now that button wasn't very well moulded - it sort of stuck a bit and was indistinct BUT IT WORKED 

[awemawson]

A bit of experimentation showed that with a light squirt of WD40 on the mould it produced far better results 

So flushed with success I ordered some hot melt glue sticks in JCB Yellow just to be a bit of a poser

[awemawson]

Now the left hand servo control has two similar switches, and although the original buttons are 'sort of' still there, they are badly worn away - simple matter to make two more buttons awaiting the return of the machine.

Incidentally here also is a picture of the welly glue - it is remarkably good stuff - I was sceptical at first but a short tear in my working wellies has stood the test of the last year

[John Rudd]

And they say necessity is the mother of invention.....

Nice job Andrew...

[vtsteam]

Andrew you've invented the manual 3D printer! 

[edward]

OT:

I use Stormsure and its brother, Aquasure, to repair my dry suit for diving. if you get the surface prep right and give it a good wipe with Cotol 240 before you apply it, it is near impossible to remove. mixed with fine sand it makes a good non-slip surface.

For quick waterproof fabric repairs, there is a flexible tape product called Tear-aid which is amazing stuff.

Andrew, your repair and problem solving skills are facinating to watch, thanks for documenting them.

[awemawson]

OT:


Andrew, your repair and problem solving skills are facinating to watch, thanks for documenting them.

Well thank you Edward. I come from an era when things were fixable, not throw away, and I've spent a professional career fixing complex systems for others, often against the odds and in quite critical situations. Failure to fix was never an option, and if you start from the premise that it's fixable you get in a mind set that helps hugely !!!

[edward]

Despite being only 42 (!) I have inherited the same mindset from my (now sadly deceased) grandfather. I also inherited my little old Drummond lathe, manual shaper and drill and lots of tools from him.

It really upsets me to see what gets chucked away. Currently repairing an electric toy quadbike for my son that was chucked away by a neighbour. It needed a quids worth of nylon gears and a dab of araldite. Cost over £100 from the toyshop! Not quite the same as your JCB though!

[awemawson]

Well I'm pleased to report that the second hand Orbiter rotary coupling is now fitted and (so far !) not leaking 

Chap is now able to concentrate on finding one more hydraulic oil leak that may or may not be coming from a spool block in a very inaccessible position, under the floor but also under the seat assembly. If he can't find it I may have to pop over with my 'camera on a wire' - it's a 10mm diameter usb camera on a long cable intended for sewer inspections - all of about £10 on ebay !

... something like this (not exactly mine) :

http://www.ebay.co.uk/itm/5-M-10-M-USB-Endoscope-Borescope-car-Inspection-Wire-Snake-Scope-Drain-Camera-/121401829087?pt=LH_DefaultDomain_3&var=&hash=item1c441ce6df

[vtsteam]

I've got one of those, and have used it to check inside the PM pipe boiler I built. Quite handy.

[awemawson]

Well I reckon we've found the hydraulic oil leak. It seems to be coming from between 'slices' of the valve block - hard to be absolutely certain as access is so difficult, but that's what looks to be happening. They clamp together with rods though the stack, with common oil feed and return down the centre, with 'o ring' seals between the slices. It is leaking even when no spool is operated so on the 'neutral' circuit.

Plan is to remove the block and try and prove the fault on the bench, then replace the O rings and try and 'unprove' it 

The machine that I sourced the Orbiter from has already had this spool block removed    traced another one but it's been toasted in a fire, then finally found one in Southern Ireland for £700 plus VAT (£3000 new) so really want to avoid having to buy that one if possible 

[mattinker]

Andrew, if it's between the "slices" and in the neutral position what else could it be but "O" rings? shouldn't need anew one unless there other surprises!

Regards, Matthew.

[awemawson]

Yes that's my thought as well. Trouble is Matthew it is bolted to a solid chassis that is hidden under another plate as it's not possible to see the oil emerging, only the trickle when it has emerged 

In the pictures below it doesn't look too bad, but actually getting spanners on it is pretty awful. The rear connections can only be acessed by removing the engine sump protector and coming in from the rear.

[mattinker]

Hmm, a nightmare!

All the best! Matthew

[Pete.]

Man I had one of those type of leaks on an old Brokk at work. I had the spool valve block apart twice before I found it was a crack in a small bore steel link pipe at the bottom of the stack.

It's always the hard to get at bits that give trouble.

[awemawson]

Well the diagnosis was wrong 

In fact (having had the block out and re- O ringed between slices) the leak is actually from the sliding spool itself - ie it's worn or the bore is worn  or more likely both

Wasted a week with a red-herring where a breaker claimed to have a spare full block of all the spools (but he didn't - it was a different one!) so have ordered a spare spool "slice" from JCB (please pass the hat round) - should arrive tomorrow 

[vtsteam]

This is kinda sounding like my Ford tractor after I first bought it Andrew, -- lots of unfortunate discoveries!

Nevertheless, I'm now glad I have it. 

[mattinker]

Well the diagnosis was wrong 

In fact (having had the block out and re- O ringed between slices) the leak is actually from the sliding spool itself - ie it's worn or the bore is worn  or more likely both

Wasted a week with a red-herring where a breaker claimed to have a spare full block of all the spools (but he didn't - it was a different one!) so have ordered a spare spool "slice" from JCB (please pass the hat round) - should arrive tomorrow 

It had to be the only other place possible! Well, it's hopefully the answer!

All the best, Matthew.

[awemawson]

Well at last the JCB 803 is back home, and certainly from a first inspection 'seems' not to be leaking it's hydraulic life blood 

It turned up this evening on a flat bed behind a friends huge John Deere tractor, that has tyres taller than me (and cost £8K a set). Not done much testing as it's nightfall, but one interesting fact is that the dozer blade, that was a bit under powered and lazy previously, now is energetic and easily capable of lifting the machine. It's the valve spool for the dozer that was leaking, so I expect that it was not only leaking to the outside world, but also internally across the spool flow and return.

Lots more to attend to - need to put the floor back, rebuild the end of the dipper with new bushes and pins, then replace a few grease nipples and give it a good service, but that won't happen tomorrow, as I have 100 kg of dis-assembled piglets to turn into bacon and ham after I collect them from my commercial butcher, who cuts the carcasses to my specification. In this case it was three 5 month old Saddleback boars weighing in at 55, 54, and 49 kGs live weight that as I say should produce 100 kg of meat.

[mattinker]

Good news about the JCB, these things are sent to try us!

Regards, Matthew.

[Will_D]

In this case it was three 5 month old Saddleback boars weighing in at 55, 54, and 49 kGs live weight that as I say should produce 100 kg of meat.

Great news about the JCB It will be great to see her restored and not leaking

Now about the 100's of kg of meat (note howe I slipped in the 's  )

It is customery on this site to offer something in exchange for something else 

So hows about 5 kgs of steel offcuts for a bit of pork   

Only joking Great news all along

Will

[Pete.]

Wehey - all round Andrew's for bacon sarnies and black pudding