JCB 803 Saga

[awemawson]

I'm glad you found the puncture, but I was a bit disappointed about the clay pigeon thrower!

Cheers, Matthew.

Update on that Matthew - we gave it much violence later on, knocking it very roughly back into shape. Then welded back the bits that broke off in the process. It has bars that channel the clays into the firing line and I don't know how critical their alignment is.

Whether it will actually work is debatable

[mattinker]

So there is a glimmer of hope!

[awemawson]

  :doh:Yesterday was the day of the TWIT, with me in the starring role 

All done and dusted, clean up, put the tools away, wipe down the controls with a clean rag, give the hydraulic tank a final top up (all rams need to be in the fully closed position for the level gauge to read correctly), then move the boom and dipper and bucket back to a more convenient position for parking up. Half way through I lost all controls, no movements at all. Hang on, what's that volcanic eruption just to the rear of my seat?

I'd forgotten to screw the hydraulic filler cap back on. This is actually the top of the filter unit and return oil enters just below the filler under slight pressure. I'd dumped about 35 litres of brand new hydraulic oil EVERYWHERE 

35 litres of oil makes a BIG MESS  Now fortunately the inner farm yard is deep road planings, which love a bit of oil to make them bind better together. Well they got a bit more than a bit !

I swept what I could off the concrete, and onto the planings, and the plan was that when I got back from the abattoir this morning, I'd dig out my steam cleaner, fire it up and steam clean the oil off the concrete. It's always been a bit temperamental firing up when it's been idle for a while, but try as I might I could NOT get the burner to fire. Ended up just pressure washing it off which worked remarkably well.

But I can see that I need to find a few days to 'breathe' on the pressure washer. It has a flame failure device that uses a CdS cell to look at the flame and decide whether to pump the oil or fire the ignition and I think I need to re-build it. I'd fit a commercial flame flailure unit from a domestic boiler, but this runs off 12V DC as the machine is completely self contained and doesn't use mains.

[lordedmond]

Andrew

Are you sure you bought a JCB and not the Tory Canyon


If the size of the oil slick is a thing to go by


Good work on fixing it up but it seem that it has to have the lat word/spill

Stuart

[Will_D]

 Before doing anything radical to the FFD just check to see that the glass window/cell is clean as a build up of soot cuts down the light entering the photo cells!

[awemawson]

Will, that was one of the checks I did. Had the CdS cell out and cleaned it, also the (very) thin glass window, which at some time I must replace as it's in two pieces! I suspect in fact thinking about it, either diesel isn't being sprayed in, or the ignition system isn't firing.

When the time comes I'll start a thread just on this subject rather than divert this one.

Meanwhile I put all the removed tracks, sprockets, idlers, and dipper parts on eBay this morning starting at 99p - hopefully they'll help someone stuck for funds sort out an otherwise marooned digger.

[vtsteam]

Good to catch up here and see you're through the problems,  Andrew!

I remember the cap coming off my bar oil chamber on a Stihl chainsaw, without me noticing right away. I'd just filled up and was carrying it into the woods when I realized my whole right side from belt to shoes was covered in bar oil. It was a long squishy walk back. That was about a 1 pint spill. I can imagine the moment you noticed the overflow on the excavator return!

[awemawson]

Thanks Steve - good to see you back.

Tidying up after daughters wedding today. Had to remove dry hay bales from the marquee before they dropped it (time / date unknown) and also move a pile of huge slices of oak tree that had been used as cake stand and various decorations. Just as well I got on with it, as just as I finished they came to collect the marquee and it started raining!

Having to hang about waiting for the various subcontractors (generator, chairs ,dance floor, bar etc) to collect their stuff I was looking for a little job that I could get on with but easily put aside, so decided to try and sort the wiper motor out.

It's a dual speed one with parking, and I'd already removed it to investigate and found the motor stuck solid, so time to dismantle and look further.

To remove the motor you have to remove the worm wheel. To remove the worm wheel you have to remove the mounting bracket.

Lots of pictures as I used them as an aide memoir for re-assembly.

[awemawson]

So at last being able to remove the motor it was obvious that it had filed up with water and rusted nicely over the last 18 years or so 

The whole thing is assembled by sliding the components into a deep pressing that is the outer casing that has permanent magnets bonded inside. So disassembly had to be from one end. The brush holders are a pair of nylon mouldings held into the case by swaged lugs which proved quite hard to release. One of the brush springs was a total write off as it had rusted through.

[awemawson]

At this stage I thought that it was a write off, but decided to press on anyway and see what could be done. Actually the armature cleaned up quite reasonably, as did the magnet holding case. I even managed to rescue the sintered bronze bush on the inner end of the armature and clean it up and soak it in oil.

Then I had to find a suitable spring from my spring hoard. I had quite a job getting one brush to slide nicely. It derives it's two speed function by having brushes set at differing angular locations.

[awemawson]

So now it's a case of putting it all back together and seeing what happens!

I did check leakage from the windings to the spindle. Initially it was reading 5K ohms - not too concerning for a 12 volt motor, but obviously better if the leakage wasn't there at all. I gently warmed it using the workshop hot air hand drier, and the leaking slowly came down, eventually getting to about 120k ohm.

So back together:

[awemawson]

so a quick bench test - just the motor as the parking wiring / contacts is rather complicated and needs the two pole three position switch that's in the machine.

Well slightly to my surprise it works ! Both speeds work and the crank goes back and forth giving the correct motion.

Popped it back in the machine, and yes the parking function works 

So now that I'm on a roll I re-fit the wiper blade and adjust it, BUT the motor hasn't the torque to reliably move the blade, even wetting the screen 

Either the brushes need to 'bed in', or there is a short on the armature windings, or the magnets have demagnetised. I left it running for a while to 'bed in' but things didn't improve much. I may at some time take the armature out again and do a 'growl test' on it, but meanwhie I'll keep an eye open for one on ebay at less than the staggering £180 that a new one costs 

[tom osselton]

I'm suprised the armature cleaned up so well.

[John Rudd]

I reckon its all that grease you packed into it that's causing your problem......

[awemawson]

I'm suprised the armature cleaned up so well.

So was I 

[awemawson]

Small update:

I'd forgotten that to remove the spherical sintered bronze bush from the inner end of the spindle, I'd had to shorten it by a few tens of thou. When I put it back together I'd not tweaked the end float adjustment to compensate - this is just a grub screw and lock nut externally mounted. I've just removed it from the machine, tweaked the end float until it felt right, and re-fitted it. I reckon the armature was moving outwards a  bit and fouling on something. It's by no means as powerful as I'd like, but it wipes a wet window now 

[vtsteam]

Satisfying to get something so seemingly gone, back working again! 

[awemawson]

There's been a spate of small digger thefts in Southern England in the last few weeks - with one or two people actually advertising rewards for recovery on eBay. Considering the silly amount of dosh I've sunk into this machine I decided to fit a 'Track Lock'.

It comprises a heavy slotted plate that you weld to the undercarriage, and a sort of 'hasp and staple' arrangement slots through it, the pins of which pass through the steel 'chain' of the tracks. Stops the digger being driven onto a trailer - it doesn't stop it being lifted by a Hiab though.

[AdeV]

Surely you only need to put a copy of this thread on the driver's seat - any potential thieves would take one look & run a mile.... 

[awemawson]

Still doing a bit of tidying up on this machine. I was determined to get the horn working. The wiring was a mystery  None of the illustrations either in the workshop manual or the parts books seemed to match up. Both showed the horn as located in the right hand drivers 'pod' - not only was it a daft place to put it, it wasn't there and nor was the wiring  A bit of searching and eventually I found it where it should logically be placed, under the cab frame at the front. I pulled it off, tested it, cleaned it up and replaced it. A pair of wires were close but unconnected - on they went as their colours matched the diagram and sure enough I can now scare the sheep out of the way 

Originally there would have been a pair of working lights on the boom, and another pair on the top front of the cab. Vestigial bits of wire to the cab but all lost off the boom. A bit of searching around and I eventually found a pair of correct coloured wires emerging from the loom under the floor terminated in an AMP 'Econoseal' female connector with one pole horribly charred.

I managed to source some Econoseal connector pairs on ebay which are rated at 10 amps per way. Not sure what wattage the original boom lights were but I reckon someone had put too large a bulb in. I sourced a pair of Chinese LED lights rated at 27 watts each so far lower than the originals would have been.

The wires for the boom lights have to follow the same route as the hydraulic pipes as of course as things articulate they get bent - I think I've left enoughy slack 

Don't you love Chinese products. The lights had nicely made stainless steel mountings and nuts and bolts. 13 mm a/f nuts with 14 mm a/f bolts 

Rather than put another pair of work lights on the cab I've got a 'light bar' as it fits neatly over the windscreen and will mount on a length of 'Unistrut' - it's 120 watts so should shine into dim corners rather nicely 

(Waiting on a couple of Unistrut spring loaded nuts so not yet mounted)

[awemawson]

Another job that's been outstanding for a while is to make up some replacement covers. One of the track adjuster covers was present - the other was missing. As was the cover that keeps prying fingers out of the hydraulic oil filler and filter housing.

Both were originally 3 mm mild steel and I had a sheet of 3 mm Zintec delivered weeks ago but not got around to making them. Bright and early this morning I got on with it, cut the profiles, drilled the holes, gave them a coat of zinc rich primer and a spray of JCB yellow. I'll leave them a day or two to harden. While it was off I cleaned up the existing track adjuster cover and sprayed it as well.

[RussellT]

Well done with this machine Andrew.  Persistence pays off again.

I've always rather approved of nuts and bolts having different sized hexagons - that way you only need to own one set of spanners - but I suspect I wouldl spend ages looking for a 14mm spanner while I could find half a dozen 13mm ones.

Russell

[edward]

I did a bit of clearing up the other week and found that between the car, garage and my 4 year old sons toolbox, we have 8 13mm combination spanners and a couple of offset rings and ratchets. God knows where they have come from! Only got 2 or 3 14mm though:)

[awemawson]

Before I fit the cab roof 'light bar' I wanted to replace the window seal, that will be trapped under it's mountings. Amusingly it is the exact same stuff used on the Traub CNC lathe 

Taking the old stuff off revealed that water had been trapped behind it where the wiper arm comes to rest to the extent that there were holes in the window frame 

My first intention had been to wire brush off the rust, and make a 'bondo' repair using perforated zinc sheet to both re-inforce it and give a degree of anodic protection, but my conscience got the better of me and I decided to cut out the rust and weld a proper patch in. My first reluctance was based on the fact that access to the back is neigh on impossible, but then I realised that it is 3 mm thick and that by bevelling the patch and frame I could get perfectly adequate penetration from one side.

[awemawson]

So, mark out what needs chopping out, make a pattern, and cut a patch - how hard can it be ?

In fact it all went very well, except that first time I cut the 'wrong half' of my pattern and wondered why the patch didn't fit.  Never mind, only a matter of minutes to make another