It's BIG, Yellow and digs holes! JCB 3CX Project 8 is joining the Tractor Shed

[awemawson]

Too right Steve and Phil !

So today having totally failed removing the last screw retaining the cover round the loader controls I set too with my Fein Multi-Tool with my longest protruding 'end on' saw blade and cut a rectangle round the bolt head thus releasing the cover from the offending bolt. Then a bit of juggling to get the control levers disengaged from their rubber gaiters and at last 'the dog could see the rabbit' !

The tone tracer soon found me cable 303 - there are a pair of round plugs and sockets in the loom under this cover, and a 'proper job' would be to release them, release the pin for wire 303 and replace it, but where I have disconnected other plugs and sockets on this machine I entered a whole world of pain so this time just trimmed the cable back to a pig tale and crimped a new piece of 1.5 mm stranded and tinned cable, threading it through the floor grommet and down to the loom that runs above the chassis rail where it was crimped to the original end of wire 303 that goes onwards to the cab roof.

After much testing to prove that I hadn't disturbed anything else and that the 12v permanent feed to the cab was sound I re-bound the loom. Two wraps of ordinary sticky pvc tape first to draw the cables into a tight bundle followed by a wrap of self amalgamating tape and an over cover of Hellerman Spiral Cable Protector. Ty-wraps replaced holding it all out of danger and the rest of the gubbins could go back on. Great fun working in that cab - not a lot of room to get at things.

. . . what a lot of fuss for a single wire . . . but it's done now AND works. Things like the self parking feature of the wipers previously didn't work as they use this live feed to get back to home position - now they do 

Rear wheel put on with the able assistance of our new young gardener Eliot - Clive having retired - I wouldn't have been able to do it single handed without a lot of messing about.

[awemawson]

Continuing clearing the various electrical gremlins in this machine I turned my attention the the 'Face Level Fan'.

As received about a year ago, this fan was lying loose on the floor of the machine amongst all the detritus and rubbish that I had to clear out - It's bracket had broken and it's source cable had been pulled out of the cab light fitting where someone had lashed it in rather crudely previously. I'd already superglued the bracket once but it wasn't strong enough, and it's been kicking about on my desk giving me resentful looks ever since.

OK make a stronger bracket out of brass. The original plastic one had been fixed with two self tapping screws into the cab frame, and rather than end up with loads of holes in the frame I stuck with the same spacing, marking out the same shape on a bit of thick brass sheet kindly donated by the plunger EDM machine.

The central thread was 16 mm o/d by 1.5 mm pitch, and by sticking with the same size I could re-use the original retaining knob.Roughing out the holes & slots on the milling machine and the overall shape on the band saw gave me an approximate shape to file and band face to the correct dimensions.

Then the male 16 mm thread was silver brazed into the mounting plate and everything cleaned up on the wire wheel before a test fit. I increased the size of the mounting screws as the previous ones were a bit wimpy and countersunk the plate to receive them so as not to foul the fan itself.

In all a simple but satisfying repair - or is it a reconstruction?.

While I was tracing the fault that prevented the cab light working I had come across the correct wiring feed from the main cab loom for this fan (The fan was an optional extra and although this is the correct fan it's a retrofit) and rather than have the wiring 'hard wired' I'm fitting a plug and socket arrangement so the fan can actually be easily removed if it gets in the way.

JCB on the 3CX use a special socket and plug for things like the flashing beacon rather than a standard 'cigarette lighter' socket so I will use one of the JCB one in order to keep consistency. There are two varieties of the socket. A 'surface mount' version which would be much easier to mount, and a through panel version that is a much nicer bit of construction, but there isn't enough depth behind the relevant panel. I suspect I'll go with the later version and make a little box to mount it but the jury is still out on this.

Continuing the concept of sorting electrical gremlins the cab clock, which now tells the time following fixing the cab light,doesn't work in the 'back light' department - only a bulb, but a special bulb which is now on order.

Strangely the clock has four wires going to it:

1 - Ground
2 - permanent 12 v to keep time going
3 - 12 v from ignition switch
4 - 12 v from side light circuit

As the side lights can be put on without the ignition I can only assume that there are diodes between the ignition 12 volt feed and side light feed to stop it back feeding.

Seems a bit of a luxury having the clock light on when the side lights are on - an added complexity to the wiring loom !


 

[awemawson]

The 'special' bulb for the clock back light arrived - odd little things that have wings that poke through a hole in a printed circuit board, and ramps on the wings tighten the connection - well they do when the ramp has been re-bent !

However back light still not working (though original bulb WAS blown and new one IS OK  ) - time for more investigations. Metering the four pole connector on the wiring loom, Ground was where I expected it, 12 volt permanent was there for the clock itself, as was the feed for when the ignition is on, and separately the feed for when the side lights are on for the clock back light. Problem MUST be within the clock module itself.

Time for a bit of brain surgery. Usual 'popping plastic clips' dismantling got me inside. Sure enough as I previously postulated, the feeds from the Ignition and the Side Lights each go straight to their own isolating diode, with their cathodes being commoned and going to one side of the light bulb. I would expect the other side of the bulb to be taken directly to Ground - but no, no sign of any connection to it - certainly none to anything that was accessible.

I should point out that this clock module is a 'sandwich ' of two PCBs separated by riveted and soldered spacers that would be virtually impossible to undo without damaging other bits.

Fortunately I was able to poke a fine tipped soldering iron in between the two PCB's and put a 'salvage link' from a bit of track from the o/c side of the  bulb to the rear of the Ground input pin.

. . . let there be light . . . and there was, both with just the side lights, and also with the ignition being on.   

Just one more gremlin knocked on the head - getting there 

[Spurry]

Yet another job well done, Andrew. Those little bulbs seem to have been well-used by JCB in the past, but are no longer listed as spares apparently.
Are yours pattern parts? The only ones I could find (for my neighbours JCB loader) were the integrated ones with bulbs fixed into the holder, but there used to be some holders with a removable glass section.
Pete

[awemawson]

Pete the original ones have a 'pea' bulb soldered to the wing contacts of the holder - they were available for about £5 each. I bought a pack off ebay of clone for £3.13 including postage. The black plastic is noticably softer than the originals, and I had to tweak the wings to make proper contact, but they work. My side console dash is tull of them hence the x10 purchase !

https://www.ebay.co.uk/itm/354054545304

[awemawson]

I finally finished fitting the face level fan 

(how alliterative was that  )

I'd sourced a neat little die cast box off eBay (though actually Rapid Electronics) and fitted it to the cab a few days ago, and was waiting for a 'curly cable' - again from eBay. The fan can be moved to point at you whether you are in the front or back seat, so I decided that the extra movement of the curly cable was well worth while - anyway it was only £2 ! Obviously surplus from some nice equipment as it is super fine strands with reinforcing cotton or polyester up the middle. Mind you this meant that it had to be terminated with crimps and ferrules.

The original connection at the fan end was by 1/8" miniature push on 'mini lucar' connectors which amazingly I had in stock from some long forgotten project so I was able to do a pretty neat job of it.

All connected up and working on both speeds (knob Off - Slow - Fast co-axial with fan motor) it's another 'little job' put to bed.

[awemawson]

At long last I've got round to a job I've been putting off for months. The engine was being over cooled, the temperature guage only just came off the base line, and I strongly suspected that the thermostat had failed or maybe wasn't even fitted.

Well today has been a bit warmer and I had a free morning - so get on with it.

One part of this job I'd really not looked forward to was draining the coolant - drain plug isn't ideally placed - so I used a trick a plumber friend of mine showed me some time ago. Slacken a hose clip, ease open the joint slowly and use a Wet & Dry vac to suck the fluid as it comes out. Worked splendidly with barely a drop lost on the floor.

Once the top hose was off the thermostat housing there were six M8 bolts to undo - the usual five easy ones, and one who's flats had previously been rounded off. My Irwin bolt remover worked splendidly and the housing was mine to clean up. Scraped with a razor blade paint scraper, tickled with a rotary wire bush and the cast iron housing and flat on the block cleaned up nicely.

There WAS a stat in there, and it was closed so all very odd so why over cooling?

Anyway it all went back together - new stat, new gasket, smear of HiLoMar, and bolts torqued down. I've temporarily replaced the rounded off one with a standard hex head - originals are flange bolts. I'll order a new one when next I place an order but not worth doing as a one off as postage swamps the goods.

I was able to re-use the coolant - I had cleaned the bucket of the Wet & Dry vac carefully so I could do this as I coolant was changed when i got the machine and is beautifully clean.

 Machine set for a fast idle while I cleared up and then monitored it with the IR meter. Stat started to open at about 85 degrees and now for the first time in my ownership the temperature gauge shows sensible readings nicely at midle travel of the needle.

 . . job's a good 'un 

[awemawson]

This really has me puzzled, I tested the old thermostat in a pan of boiling water - it resolutely stayed SHUT. So why was the engine over cooled and not overheating

The over cooling was cured by installing a new thermostat so this defies logic - can anyone give me a logical explanation of what's happening here ?

[ddmckee54]

The bypass hole in the old thermostat looks huge, was the hole the same size in the new stat?  If that was bypassing too much coolant into the radiator that would keep the engine temp low.  I haven't changed THAT many thermostats, but I don't ever remember seeing one with a hole that bit.

[awemawson]

if you mean the second hole in the cast housing, it is blanked off by a flat face on the engine block.

(I imagine it's a part also used on bigger engines that use a pair of thermostats - my Dorman 110kva generator is like that with two stats to give adequate coolant flow)

[David Jupp]

Now it has been mentioned the hole (without the expected jiggle pin) does look large.  Without jiggle pin it will always pass water too - jiggle pin usually shuts flow off when engine is running.

[Roger B]

I could suggest that it was stuck open until you started disturbing the housing and then it dropped shut. As it didn't open under subsequent heating it was obviously faulty. Can you push it open by hand?

[awemawson]

Nope - I couldn't shift it at all by hand.

binned it !

[ddmckee54]

Andrew:

I was talking about the hole in the thermostat visible at about the 7 o'clock position in the photo Offending Thermostat #2.  I believe that the hole is there to limit the pressure on the coolant pump seals when the thermostat is closed.  That one seems a little excessive.

Don

[awemawson]

For a long time I've been puzzled by an hydraulic leak from the back end - puzzled in being unable to locate it that is !

There are 6 hoses formed into a 'trombone shape' conveying fluid to the various services on the back actor - (they move side to side as the boom is side shifted) - they'd got pretty grubby with mud so I cleaned them down the other day. Five minutes later oil was dribbling down the hose nearest the front of the machine. Was this my mystery leak? Only a small dribble and no sign of damage to the hose. A few more cleaning & trying cycles and yes certainly something was leaking. Both ends were tight (1/2" BSP female) but bally difficult to access.

So I ordered up a hose, and also a 27 mm 'crows foot spanner' the more easily to undo the ends. A bit of time today so I started. The whole rear arm needs to be lain on the floor just so things don't descend suddenly when opening hydraulic joints, so a bit of tractor shifting first then lay the boom down.

Old hose eventually was cajoled off and I realised then that the 'energy chain' that these hoses run in was packed with oil laiden mud so would have to come off for cleaning. Now oddly there was no sign of any damage on the hose that I removed.

With the boom down on the floor it was obvious that one of the 'crowd' cylinder hoses had come to the end of it's life - worn down to the inner of the two braid layers. Again 1/2" BSP - straight one end and 90 degrees on the other but I hadn't ordered a spare 

Fortunately I had suitable ends and hose so I crimped up a custom part. Everything fitted back together without too many dramas and what's more there is no leak!

I tested it without the 'energy chain' so that I could feel all round the hose - glad to say all's well and I refitted the newly cleaned energy hose.
                 

[awemawson]

Carrying on with the 'sort all those little jobs' theme on the JCB I today fitted the near side hose guard. When I got the machine the original (JCB Yellow) hose guard was very mangled and I've not been able to source a replacement. It's bent from a sheet of 2.0 mm yellow HDPE sheet - and I couldn't even find a source of the sheet unless I bought a metric ton of the stuff, so I bought black. The black sheet has been kicking about my workshop while I remained in hope of either finding the real thing or yellow sheet.

But no - so yesterday it got cut to size. I had heated up, ironed out the mangling in the original, and plastic welded it with a soldering iron to be able to get a decent pattern, but the plastic welding isn't strong enough to bend it to use it.

Now before fitting it I decided to steam clean all the plumbing behind and about it - not only makes the fitting job more pleasant but helps enormously in tracking any further hydraulic leaks.

So that's one more job off the list. The ram for the offside front bucket crowd function has a small weep so at some time soon I need to pull it apart and replace the seals. Fairly straightforward job apart from the sizes involved - cylinder cap nut for instance is 65 mm AF and on at a huge torque so that will be fun. I made a 65 mm 'flogging spanner' the other day on the CNC Plasma Table in preparation.

[awemawson]

When I made up the excavator bucket crowd hose the other day I blindly copied what was there - except that it had 'hose wrap protector' on it to save it from chaffing. Well I had some wrap on order and it arrived today.

It's a bit of a b****r to fit to already installed hoses but possible, so that was this mornings little job. I'd just finished BOTH ram hoses realising that the other one had no wrap when I realised that the hose that I hadn't changed had a much nicer routing. It had straight 1/2" BSP female fittings on both ends whereas the one I removed had a 90 degree bend on one end making it stick out like a sore elbow !

Then it dawned on me - someone in the past had burst a hose and just used what was to hand that 'sort of' fitted' Time to make up another hose with straight fittings on both ends. It lays so much nicer in the guides and doesn't stick out like the last one !

[awemawson]

JCB's are well known for 'marking their territory' so it is no surprise having fixed the bigger oil leaks smaller ones are becoming apparent !

I noticed today that one of the 'hdyra clamps' has a small weep. These four short stubby hydraulic cylinders clamp the 'back actor' to the 'rear rail'. Relaxing them allows the entire back actor to be 'side shifted' and in operation they are pumped up locking everything together.

The individual bits are available, but I notice that the upper pair look quite different from the lower ones, one of which has the leak. I am minded to replace them all to get to a known starting point - a full kit is available and although not exactly cheap won't break the bank - especially as I have other bits to order that will share the carriage charges.

 

[awemawson]

I have Hydra-Clamps and Rod cylinder seals on order but not yet arrived, so I decided to tick off one more 'get round to it one day' jobs on the JCB.

The cab doors were both originally equipped with 'door stays' allowing the door to be fixed a few inches open to get a bit more ventilation while working. Near side was present but off side has gone missing. Just an 8" length of 1/4" bar screwed into a ball joint at the tethered end, and a special button fitting that engages with the door lock at the other. Zero dealer stock and anyway listed at £24 plus VAT - so make one !

6 mm ball joint ordered on eBay (£2.99) - 1/4" bar from stock as was a bar end to make the button. Simple turning and threading job had the bits ready before the ebay delivery - which was today.

I glass blasted the parts and cold blued them with 'Perma Blue' and I was impressed with the finish it gave me - not used it before - I've had it on the shelf for a while having bought it on impulse !

All bits Loctited this morning and I've just fitted them - seem to work OK and indistinguishable from the originals 

In the 'parked' state the stay sits on a little clip holding it out of the way - clip was missing - also unobtainable - so I 3D printed one.

[awemawson]

My long awaited parts order has arrived so work can commence.

a/ Correct flanged bolt for Thermosat housing

b/ Four Hydra Clamp seals, bolts, nuts & Lock Washers

c/ Four hydraulic cylinder seal sets to cure a few weeps

So first do the trivial flange bolt replacement - original had had to be removed with a bolt extractor and I'd temporarily substituted a normal bolt - job done.

Then paying attention to the hydro-clamps I find what appears to be a custom made extra bracket spanning between the bottom two massive bolts - can't find it on any parts listing - it'll have to come off to replace the hydro-clamps but I can't really see what it's intended purpose was - need to ask a few questions.

[awemawson]

So I've just crawled back to the house after 7 solid hours fighting the hydraclamps and that strange bracket. It turns out that the bracket supports the breaker return hose that passes under the back actor to stop it dragging in the mud.

I'd intended to do one side at a time as the 38 mm through bolt (which I was replacing) can only come out at the extreme ends of the channel that the back actor slides on so doing both lower ones for instance means keeping on sliding the whole rear arm on it's mounting. Not only is this a fag, but it means that you need plenty of space either side of the machine as the rear arm is used to push the mounting side to side.

However with that pesky bracket on the two lower bolts / hydraclamps I had to do that pair and suffer the inconvenience - which is one reason I've only done two of the four in a seven hour stint.
Once the bracket is removed (it then dangles on a heavy hose) the back actor has to go to extreme left and the 38 mm bolt then can pass through a cut out on the front of the rear rail. The new bolt can then be inserted, however it has an anti rotation lug sticking out that has to be aligned (by feel!). Then the back actor has to be slid to the extreme right and the process repeated.

Then comes the tricky bit that took absolutely ages ! The one piece bracket thing has to be placed over the left and right hand bolts without either pushing them out of the channel or disturbing the location of the anti-rotation tabs. Meanwhile it's heavy hose is pulling it out of your hands and the bracket is springy so the hole spacing needs tweaking . . . . 

Needless  to say it was  an iterative process involving an excess of frustration, but I got there in the end.

Actually rebuilding / resealing the hydraclamp units was simplicity itself - douse everything in hydraulic fluid and press them together. The old ones were a bit manky !

Hopefully the upper hydraclamps will be much easier, and in fact I may not replace the bolts as they look to be in better condition than the lower ones.

[awemawson]

Well the good news is that the Hydro-clamps no longer leak 

But the bad news is that they probably will soon as they are not sitting flat on their seating 

Why - well it's all down to that blooming bracket that I spent most of yesterday wrestling with. It's obviously not original but I now (having crawled under!) see why somebody installed it. It gives a forward support to the flexible 1" BSP breaker return hose stopping it dragging in the mud. Sadly whoever made it got it slightly wrong 

The body of the bracket fouls on the base of the back actor carriage forcing it into an uncomfortable angle resulting in the 'tabs'with 38 mm holes for the hydra-clamp bolts to not be vertical - thus they are not sitting flat.

I've decided to make longer tabs to hold the bracket a good inch or more lower - by cutting off the original tabs just below their 38 mm holes I can leave an upright bit to bolt my new tabs to. By slicing the forward part of the bracket I can get it off the machine without draining all the hydraulic oil and it can be bolted back together.

This way the currently one piece bracket will be in four separate pieces greatly aiding refitting it - and the entire caboodle can sit at least an inch lower no longer risking fouling the base of the carriage.

I was manoeuvring 8 mm plate on the plasma cutter to make the new tabs when I managed to dig a small chunk of skin out of my finger - a very small wound (but deep) that won't stop bleeding so I've stopped for the day to let the platelets do their work !

[awemawson]

So with the bleeding stemmed this morning I've completed 'phase 1' remove the bracket, prove that the clamps seat properly with no bracket fitted, and slice the bracket ready for modification.

The tabs on the bracket are fairly grossly bent - I suspect whoever made it didn't leave enough bending allowance for the 8 mm plate that its made from resulting in it fouling the base of the back actor. To get  it to fit over the 38 mm clamp bolts the tabs had to be bent which is why we are where we are.

Still enough forensic engineering - what to do? Draw up and cut longer tabs with the 38 mm holes, slice off the originals and arrange holes in tabs and bracket to fix them on. But first I need to bend the tabs to true 90 degrees so my longer replacements sit vertically. This may involve heat - I may have to fire up the ceramic chip forge but I'll see what a sledge hammer does first. best done before cutting the old tabs off to give more leverage.

However other matters now demand my attention so play will have to cease 

[awemawson]

I managed to sneak away for another half hour. As I'd feared blows from a sledge hammer failed to give the results that I wanted. I tried the 60 ton press but not really suitable, so . . . . . fire up the Ceramic Chip Forge 

It's many months since I've used it and I was delighted how easy it was to set up and  quick to get up to heat. Once those bends were glowing it was dead easy to coax them to shape - too easy really as I overshot and had to bring them back again.

The angle is now much closer to 90 degrees - I only want the bottom 1" straight as the rest is getting cut off anyway.

(amusing to think that the propane bottle that I used came with me from Bromley in 2007/8 when we moved here - old gas  )

Got to resume other duties so the rest will have to wait 

[tom osselton]