Author Topic: It's BIG, Yellow and digs holes! JCB 3CX Project 8 is joining the Tractor Shed  (Read 24219 times)

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
Well I got quite a bit more done this afternoon:

a/ New longer tabs drawn up in Autocad and cut out on the CNC Plasma table

b/ Old tabs cut off and remains of the bracket trimmed up

c/ Forward arm for the pipe support trimmed more neatly

d/ New tabs and bracket drilled for 8 mm bolts to fix back together

e/ Bracket assembly loosely put together and offered up to the clamp bolts to test the 38 mm hole spacing.

NB the nuts were left on the the clamps bolts so the back actor was safe and an other pair used to pull the bracket into place.

I suspect that a bit of fettling will be needed for the final fit - I'm not certain the the pairs of 8 mm bolts holding the new tabs on will clear the body of the hydraclamp - time only will tell.

So a bit of fettling then drill the forward part of the pipe clamp to match, then dissemble, clean up and paint before final assembly. Probably not for a couple of days as we have house guests coming for the weekend.

Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
This morning I managed to finish the fettling. It was just a case of relocating the new tabs to the other side of the original tab stub to give enough clearance for the body of the hydra-clamps.

I then with great trepidation drilled the holes in the bracket that is still attached to the 1" BSP breaker oil feed - very easy to put the drill right through the hose especially as acess is fraught - anyway I didn't  :thumbup:

So all that remains is to remove the assembly, strip, grit blast and paint, and re-assemble using shake proof nuts. Then the hydra-clamps can be properly torqued down, tab washers locked on and any air bled from them.
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
House guests this weekend so not much done, however my muscular son had a go at undoing the nuts for the upper hydra-clamps - no, no joy I will have to cut them off when the time comes.

Meanwhile I've just grit blasted and sprayed the modified lower bracket in red oxide primer - hopefully it'll be RAL 1007 JCB yellow tomorrow !
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
I got the first coat of RAL 1007 JCB Yellow on this morning before 09:00. Hopefully this will let me put the top coat on in the late afternoon to give it over night to harden up a bit.

Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
This morning I re-assembled the breaker hose bracket that I recently painted and re-installed it on the lower hydra-clamp bolts.

I won't torque them up until I've sorted out the upper clamp stuck bolts. Apparently there is a lug projecting from the clamp plate that slides in the rear channel and take the weight of the back actor. This lug engages with a flat on the 38 mm bolt head to stop rotation and it seems that we managed to sheer a bit of it off in our attempts to free the stuck nut. New one on order. Also on order is a longer reciprocating saw blade to cut the bolt off.

Andrew Mawson
East Sussex

Offline modeng200023

  • Full Member
  • ***
  • Posts: 130
  • Country: gb
Going on like this Andrew, you'll soon have a new machine with al the replacement parts you've fitted.  :D

John

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
Yes it rather feels like that John.

Once you're into something like this there's no point in not sorting out things as you find them, or they'll come back and bite you in the nether regions.

Classic example this morning - crawling about fitting that bracket I noticed that the hydraulic hose for the near side slew cyllnder had been chaffing and worn though it's outer sheath. 1/4" BSP female ends, 1050 mm long and not available from the supplier that had the plate clamp in stock, so extra postage from another supplier but 34 each and no point in not replacing both. As luck would have it I have the 1/4" BSP ends and ferrules and the hose in stock so I've crimped up a pair of hoses this morning ready for when I do the job.
« Last Edit: May 02, 2023, 02:31:36 PM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
The Replacement hydraclamp plates arrived this afternoon so I got on with sawing off the offending bolt to release the nut that's been giving me grief. By heck it was a tough bit of steel!

One hour and a half of sawing, and three reciprocating carbide tipped blades later, (using coolant as well) it was mine and the rest of the job was pretty simple. Knock out the remnants of the 38 mm old bolt - remove the old plate - and install new plate and bolt ensuring that the lug aligned with a shaped head of the bolt.

I've not at this time replaced the actual seals in the hydraclamp to avoid duplicate oil draining- I will do when I do the bolt on the other side but frankly when the bolts and nuts are undoable it should be very easy.

Lots of copper grease used on the nut and bolt when re-assembling to help the next bloke down the line.

I was rather surprised how little of the anti-rotation lug had been chewed away on the old plate. I'd wondered if I could have built it up with weld but in the end decided that it was a false economy on what is a highly stressed part.

. . perhaps do the other side at the week end depending on other pressures.
 
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
The forecast for the weekend was rain, so I decided to get on and saw off that offside hydraclamp bolt. Didn't go too badly but still took ages and several saw blades !

So having got the new plate and bolt installed (no pictures, just like the other side) I went ahead and changed the actual seals inside these upper hydraclamps - so now all four are new.

Now to get at the bolt the boom has to be slewed all the way in one direction and the carriage slid to the extreme end of the support channel. What I DIDN'T know was when slewed to 180 degrees either side, that bracket that holds the breaker hose up was fouling on the slew cylinder steel pipework that is part of the cylinder itself. Although the pipes are not leaking they have been compromised.

So now I need to work out a more satisfactory arrangement to support the 1" hose for the breaker AND a repair strategy for the slew cylinder pipes. I've taken the new bracket off and have temporarily supported the pipe with a bungee cord.

 . . . one step forward . . two back . . .  :bang:
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
OK time for a bit of lateral thinking regarding this pesky hose bracket.

There is barely an inch of available clearance between the top of the slew pots and the bottom of the hydraclamp bodies. Not much space especially as the carriage will not necessarily sit exactly horizontally due to play in its mounting. It seems the original JCB fitting routed the hose ABOVE  the carriage and had a loop to allow for side shift and the pipe was then routed into the guts of the machine. I've attached a picture of how it was supposed to be - nothing like mine !

Now I don't HAVE a breaker. I don't NEED a breaker. So why the heck go to great lengths to support its hose - take the blooming thing OFF !

So my objective this morning before watching the Coronation was to take off the hose and fit blanking adapters to where its ends were. The solid pipe running down the boom ends up on top of the near side slew pot - easy job, (well needed great force!) unscrew and blank off - job done. Now the other end terminates in a very oily lump of control hydraulics that at first I thought fixed with a standard 1" x 60 degree cone fitting. So I crawled  under only to find after much cleaning was in fact a 1" BSP Quick Disconnect flat faced fitting. more cleaning and a few more grunts and eventually it was off - the hose was mine !

A bit of a daft place to fit a QD fitting - should have been plumbed to a place that was more easily accessed.

A quick washing of hands and I'm just in time for the big ceremony with Zadok the Priest being played at high volume on the telly - phew marital harmony preserved AND the hose is off :lol:
« Last Edit: May 07, 2023, 02:56:29 PM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
When I'd finished removing the breaker return pipe I steam cleaned the oily bits where it came from, however my Karcher HDS550C was playing up. It would fire up every time water was blasted but would stop firing or pulsate, and the water although hot was no where near the intended 99 degrees C.

So first job this morning was to sort it - I've not had this machine long - bought locally on Facebook Marketplace I used it a couple of times last year then it got put away for the winter to save it from frost. Sounded like fuel starvation to me, so possibly pump coupling slipping, blocked jet, or maybe it has a fuel filter. Oh yes - tiny little gauze affair in a die cast housing. Filter removed, blasted with compressed air and seems very free to certainly my blowing ! Re-installed and yes we are up and running and can get on with the intended task of the day which is to prepare for replacing the seals in the offside bucket  ram on the 3CX. Fingers crossed this is the only remaining significant leak left to fix.

Now this ram has the 'Return to Dig' feature clamped to it - this allows the bucket to be lowered from on high back to exactly ground level plus a tad by pressing it's control lever over into a detent position allowing the operator to concentrate on aiming the beast at the pile to be scooped up. Feature is very simple - a rod is fixed to the bucket end of the ram and passes up a tube that is fixed to the body of the ram that has a microswitch that the rod operates when the bucket is at the correct point.

Rather crudely fixed by a pair of Jubilee clips around the body of the ram, with the rod being bolted on. Rod was easy as were the Jubilee clips, but the nuts holding the microswitch were thoroughly rusted and had to come off with a nut splitter.

So with the wiring Ty-Wrapped out of the way I could slip my 'chrome protector' (split pipe) onto the rod, and apply a mighty Swedish pipe wrench to the cylinder cap - no, no movement - even with a fair length of scaffold pole on the wrench - no movement. That's as far as I've got. I may have to apply heat to the cap, but once I do that the seals will be totally destroyed and at the moment we just have a little weep !

. . . time to cogitate I think.
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
The 'book of words' suggests sealing the end cap with brown  Loctite 932 which is a low strength thread locker able to be dismantled with hand tools.

There is no knowing if someone in the past hasn't just grabbed the nearest Loctite bottle - maybe red high strength - which Heinkle say needs 250 degrees C to release which I'm sure will destroy the existing rod seals.
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
Putting the slightly leaky bucket cylinder problem 'on the shelf' for a while while I cogitate I turned my attention to the two 'slew pots' that swing the back actor.

As you may recall the welded on pipes on these cylinders have been scalped by that pesky bracket, and whether I try to weld on new pipes, or if I replace them they will have to come off. They are each retained by four blooming great 1" bolts that are torqued up to 970 Newton Metres  :bugeye:

I had already attempted to undo them with my 3/4" socket set and a 5 foot scaffold pole to no avail. More in hope than expectation I had ordered a cheap Chinese 'Torque Multiplier Set' on eBay - proper professional ones cost several hundreds of pounds so I didn't expect much for my 60 including postage. There were even cheaper ones on eBay but I chose this one as it came with a fair selection of sockets (including the 38 mm / 1-1/2" one I needed) and quoted a maximum torque of 3200 Newton Metres.

Well today it arrived. Turning it by hand it felt rather horrid - I wasn't over surprised, but to give it a fair chance I stripped it down to grease pack it. Consisting of three sets of sun / planet gears in a common ring gear there was a nominal bit of grease on the outer set, but deeper in there was none. I packed (probably over packed) it with a decent grease and put it back to work.

And does it work . . . . you bet your boots it does . . . I couldn't believe how easily the first bolt came out just cranking lightly on the 10" handle that is provided. The advert says it has 58:1 gearing - I didn't count teeth but I can well believe it. I think it was well worth stripping and greasing as it doesn't feel at all bad now !
Andrew Mawson
East Sussex

Offline modeng200023

  • Full Member
  • ***
  • Posts: 130
  • Country: gb
Amazing  :clap:

Offline hermetic

  • Hero Member
  • *****
  • Posts: 735
  • Country: england
A very valuable addition to your JCB tool kit! It's big, it's yellow, and it needs delivering to Langtoft!!
Phil
Man who says it cannot be done should not disturb man doing it! https://www.youtube.com/user/philhermetic/videos?

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
It'd be a long bouncy drive Phil  :lol:
« Last Edit: May 22, 2023, 11:46:58 AM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
So it's time to sort those damaged pipes on the slew pots. I've been accumulating 'bits' over the last few days and I 'think' (well hope!) I've got everything.

There are very few videos on YouTube showing pot removal but many showing the difficulty of re-installing them - much heavy hammering and grunting. So I needed to plan a re-installation method that didn't involve many beefy blokes with big sledge hammers and hopefully relied on subtly rather than brute force.

My plan is to make two studs threaded 1" UNF that can screw in where those big bolts fit. and be counter-threaded M12 so that M12 studding can be used with a spreader bar across the rear of the cylinder to pull it back onto the new piston rings and seals. Two lengths of high tensile M12 studding ordered and I already had M12 coupler nuts that will give greater thread engagement. I should perhaps explain that an M12 Hex nut will fit through a 1" hole so the puller / pusher can be removed when finished !

Where to find some 1" UNF studs - I was about to set up to thread some when I happened on some pivot studs left over from when I had a Fordson Major tractor - they were part of the three point linkage.

Also I needed heavy wall drawn tube to make up the replacement for hydraulic feed pipe  that is damaged and causing all this fuss. Original was 31/64" by 14 SWG - the nearest that I could find was 1/2" by 1/4" bore - slightly smaller bore but the flexible hoses feeding it are 1/4" so I don't suppose it will matter a jot.

OK now I need a seal / ring set for both sides which arrived this morning.

So no excuses - get a pot off ! Our satellite dish had gone wonky and while the chap was fixing it (corroded 'F-Type' plugs) I left the slew gear box draining into a sheep lick bucket.

Next job - remove the bracket from two of the pot retaining bolts as it obstructs the other two bolts - replace them but with heads protruding about half an inch. Slacken the now exposed other pair of bolts a similar distance then . . crank up the engine (keys have gone missing - use the spares !) lift the back arm up so that the bucket is just off the floor and slew boom to off side thus pressurising the near side slew pot. This pushes it off a bit until it hits the bolt heads. Cut engine - wiggle hydraulic controls to release the pressure - uncouple the hydraulic feed pipe and cap it off - remove those huge bolts then gently lever the slew pot off the piston assembly. And it's blooming heavy !.

OK one pot off - I'll do one pot at a time I think.
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
So now the pot is on the bench I can have a good look at it.

Bore looks to be in good condition. The shaved pipe seems to enter tangentially and oil flows into some sort of baffle arrangement deep in the outer end of the cylinder.

Tomorrow I need to carefully mark up where the pipe runs on the cylinder and try and replicate it - that'll be fun !
« Last Edit: May 22, 2023, 12:31:52 PM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
Today I sliced off the damaged pipe, bent a new one and welded it on . . .

. . . .sounds simple doesn't it ! Well it wasn't. Cutting off the old was easy. Cleaning up the barrel and milling a 1/2" recess for the new pipe was easy - well the fixturing took a bit of head scratching - (the clamp that seems to be on the inside of the bore is actually on a bit of soft aluminium)

What took the time was bending the new pipe to shape and welding it on. It is a very odd compound set of curves - I was doing it hot in the forge but got an approximation in the end !

Welding was never going to be easy round the 'back' of the pipe close to the cylinder wall and I'm by no means certain that it's going to be hydraulically sound - time only will tell. I can't pressurise it for testing so at the moment am relying on the 'blue towel test'. Blue workshop towel goes much darker with the slightest bit of water. Currently filled with boiling water and sitting on a towel !

Andrew Mawson
East Sussex

Offline pycoed

  • Jr. Member
  • **
  • Posts: 78
andrew,
I know it's a bit late now, but if you can weld well enough to seal the new pipe against hydraulic pressure, wouldn't it have been easier to weld or even braze the damage on the original pipe in situ? It wasn't leaking as it was, so it would have been "belt & braces" & if disaster did occur, well you'd be in the same boat you are now? May be a thought for the other pipe, since one looked worse than the other?

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
Well things change ! The pot hadn't leaked against the very modest few inches of water head overnight but I wasn't happy about it. Took the dog for a walk to cogitate ! I decided to rig up a crude pressure test by cutting an 8 mm plate to rest over the open pot mouth with four holes corrspnding to the pot fixing bolts. Then, with a piece of rubberised cork gasket material started pumping the pot up using my plumbing pressure tester.

At 15 psi the weld started to leak - only very slightly but this is 15 psi not the 3000 psi that it will see in service. Cleaned up with a grinder, a bit more welding and gave it another test - got up to 60 psi and the rubberised cork gasket blew out  :bugeye: Probably I'd not given it enough over lap . Reseated the gasket and pumped up to 60 psi when there was hissing round the gasket but apparently no leak at the weld.

At this stage I thought - this is silly - OK used slew pots in good condition aren't cheap but to go through multiple test cycles - even probably putting them on the machine and having to pull them off again if they leak - life is too short - just bite the bullet and buy the used pots. Pots ordered !

I had actually decided when I got up this morning to attempt to weld up the pipe that I'd cut off as a trial, and if it went well do the same operation on the other slew pot pipe but I never got that far, getting involved with the pressure testing. I don't regret it really - I've a lot on my plate in the next few days and weeks and this will be one less thing to sort out (but I'll still have fun refitting the replacements - they may even get a coat or two of paint. The sealing plate I made for pressure testing will double up as the 'pusher' for my refitting press !)

I may have done better to dig out my oxy-acetylene set as getting a smooth flow is for me easier but I not gas welded in years. I suppose really I should set my self up for TIG welding - but I haven't !
« Last Edit: May 24, 2023, 03:49:38 PM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
So at long last my (second hand) replacement Slew Pots arrived in a battered box this afternoon. Praying that the pipes weren't crushed I opened the boxes (total of 92 kg!) and - phew - they were OK.

fortunately the bore of these hydraulic cylinders is exactly the same as a 110 mm underground drain pipe so I was able to blank the operating end with drain stoppers, and the hydraulic pipe with a standard 1/4" BSP bung. Left them soaking in de-greaser for half an hour then hit them with the hot pressure washer. They came up reasonably clean - I'd hoped it would take the paint off but no such luck.

So when they were dry they got two applications of extremely strong paint stripper and then most paint came of with the pressure washer. Again after a drying session I removed the few reluctant bits of paint with a wire wheel, then washed them in Industrial Thinners ready for painting.

The thinners soon evaporated and they got a light coat of red oxide primer which is dry already, but I'll leave it over night before starting on the RAL 1007 JCB Yellow that they will soon sport.

. . . time to make supper . .
« Last Edit: June 02, 2023, 09:49:13 AM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
Last night the primer was amazingly hard - passed the finger nail test - so I gave it a first light coat of RAL 1007. When I came back to inspect it just before bed time to my horror I found that in one or two places the dark orange pigment had settled out from the paint forming splodges.

This morning all was dry (it is supposed to be able to over coat within an hour) and I tentatively rubbed at the splodges which also were rock hard. OK I'll try another light coat and see what happens.

Diluting the paint with the thinners it started to curdle (OK the tin is dated 2016 !) so I threw that batch out and opened a fresh pot. Diluted to thin cream consistency I gave them a blush coat (it avoids runs) followed a few minutes later by a slightly heavier one which is already touch dry and no splodges this time thank goodness.

I may give them another coat but in all likely hood actually wait until they are on the machine as they are bound to be knocked in the re-fitting process.


« Last Edit: June 02, 2023, 08:17:06 AM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
This morning I removed the off side Slew Pot and then started making my patent "Slew Pot Puller" to pull the replacement over what will fairly certainly be rather tight new seals.

As previously mentioned this device requires two 1" UNC studs counter drilled and tapped M12 to take the actual studs that do the pulling, and cross bored for a tommy bar to allow tightening up and removal.

Based on a redundant pair of Fordson Major 3 point linkage pins the turning to size proved 'interesting' Being a wear part the original pin has been selectively hardened, and even carbide lathe tools were struggling in places. Fortunately the outer end was relatively soft and could be parted off and drilled & tapped M12 but turning the body down to 1" was a bit of fun. My tommy bar cross hole had to go further out than I'd intended as the material was too hard to drill !

I had thought of sticking the original studs in the induction furnace and annealing them - but life's too short !

So one down one to go - I may get time after lunch.

Andrew Mawson
East Sussex

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8920
  • Country: gb
  • East Sussex, UK
After lunch I made the second stud - great fun turning hardened steel with the swarf glowing white hot as it comes off !

So with the two adaptor studs made I assembled the slew pot pusher as a 'dry fit' on the bench - it should work - well I hope that it does ! No idea how much force is needed but some advocate pushing them on with another digger  :bugeye:

A few grandchldreny things coming up so hopefully play can recommence on Monday.

Andrew Mawson
East Sussex