PDA

View Full Version : JCB 240 Excavator







expat
27-05-2007, 09:35 AM
Hello everyone,
I was having a look at a JCB 240 excavator yesterday with the air con down. System was empty and a small area of the condenser had dust clinging to it while the rest of the condenser was clean so it seems I found the leak.
My problem is I can't find the valve on the suction line, only on the discharge line.
Also the owner has no manuals so I don't know what charge to weigh in and lastely being as the suspected leak is at the bottum of the condenser I would think I need to put some oil in.
Any help would be appreciated.
BTW are you guys having a bank-holiday tommorow (monday 28th May).

chillin out
27-05-2007, 06:52 PM
Did you check the compressor for a service fitting?
Failing that, follow the suction pipe all the way back.

No chance of a copper pipe anywhere that you could braze into?

Unless the cond was dripping with oil then I wouldn't worry too much about adding any.

And yes, we have B/H tomorrow. Are the frogs off as well?

Chillin :) :)

Karl Hofmann
27-05-2007, 08:15 PM
Don't panic if you cant find the high side service port. If you know the weight of the refrigerant charge (Which should be on a data plate somewhere) then you can charge through the suction side. Initially charge the bulk of the refrigerant as a liquid WITH THE COMPRESSOR OFF, then once the pressure has ballanced out, you can charge the ballance of the refrigerant as a gas with the engine on and the ac on, I throttle the manifold valve to ensure no liquid enrers the compressor.

It's just been pointed out to me that you are looking for the low side service port (Mental note to self, learn to read) In which case, charge what you can throuhh the high side and then warm the bottle a little to the correct weight (Although it does look a little dodgy, the mapp gas torch does this very well though you may find that people watching you may give you a lot of space)

If it is just a minor oil leak, then dont panic over the oil but you could pour a little oil in to the new condenser before fitting if you like or get your self an oil injector.

Good luck.

The sooner they ban all of these bloody bank holidays the better. Civil servants get Tuesday off too for the Queens Birthday, as if they don't do little enough already:mad:

coolincab
27-05-2007, 10:00 PM
Hello everyone,
I was having a look at a JCB 240 excavator yesterday with the air con down. System was empty and a small area of the condenser had dust clinging to it while the rest of the condenser was clean so it seems I found the leak.
My problem is I can't find the valve on the suction line, only on the discharge line.
Also the owner has no manuals so I don't know what charge to weigh in and lastely being as the suspected leak is at the bottum of the condenser I would think I need to put some oil in.
Any help would be appreciated.
BTW are you guys having a bank-holiday tommorow (monday 28th May).

Never done a 240 but the js 130 through to the js 220 holds 1.2kg for the last 3 years
remove plate under engine & pull back a little:eek: on suction hose spv sometimes slips through hole heading to cab
no holidays here

chillin out
27-05-2007, 10:20 PM
@Karl, Please re-read the post...lol
It's the suction line he can't find.


The sooner they ban all of these bloody bank holidays the better.
You must be an employer then rather than an employee....lol

Chillin:) :)

Karl Hofmann
28-05-2007, 10:16 AM
@Karl, Please re-read the post...lol
It's the suction line he can't find.


You must be an employer then rather than an employee....lol

Chillin:) :)

Doh!! Sorry for that error, in which case charge through the high side and warm the supply bottle a little to get the full charge.

I'll change my post so that I don't look too stupid :rolleyes:

I'm neither an employer or an employee, just a one man and his dog band...And the dog refuses to go up ladders:D

expat
28-05-2007, 04:02 PM
Thanks for your swift replies.

Karl you speak of replacing the condenser but I had hoped that I would be able to repair it. That is if I can pinpoint the leak.

I wasn't able to do this with my leak detector however (a little green thing called a Gx Eco by Galaxair) nor with a can of that spray stuff.

My next plan if I couldn't find the leak (and I hope I don't get a slap on the wrist here) was going to be to charge the system up and put some dye in, come back the next day and find the leak.

When I say repair i'm thinking of a bicomposite resine that I've heard of. Does this sound feasible?

Karl Hofmann
28-05-2007, 04:47 PM
I always find that the best way to find a leak in a condenser (Assuming that it has a leak) is with a garden sprayer and a strong concentration of water and foaming coil cleaner and totally soak the condenser with the system pressurised with OFN to about 200psi, may be worth putting a couple hundred grammes of R134a so that you have a chance to pick up the leak with your sniffer, but use your sniffer before you soak the condenser as the water will upset the leak detector. To be honest I have never had any luck with dye as I am totally colourblind and cant see it, and in any case, if the leak is big enough to let dye out, then it is big enough to allow oil out and that is easy to see.

expat
28-05-2007, 05:38 PM
Thanks again, I'm self employed here in France, what they call an Artisan, and I haven't been going for long.

I got this job as a spin off from installing 2 mitsubishi splits for a guy this month. He runs a business building dry stone walls with very big chunks of rock and he's got a few of these big machines.
I didn't want to say no when he called me but to be honest I have never worked on automotive before.
Anyway I obviously looked competant because he said I could maintain them all if I wanted.

Now I've been sifting through many posts, often by yourself and I have started to wonder if I'm up to this especially after I gave myself a little scare yeterday. I told my brother in law not to bother to go to BMW for his air con as I was an expert (don't worry everyone in the south of France starts talking like that on a sunday afternoon and after some Pastis and a bottle of wine.
I measure 4°c coming out of the vents and 2bar on suction, down to 1bar to 1.5 bar when he revs up. Too low I say (hick). I added some gas to get the suction up a bit but it didn't have much effect.
Then we went down the drive and when he was breaking it made a noise a bit like something jamming.
We turned back and siphoned off some gas and things went back to normal, but it nocked my confidence. What do you think happened

expat
28-05-2007, 05:43 PM
I din't say it was a 316i 1999

Karl Hofmann
28-05-2007, 09:15 PM
Ha Ha, Leave off the vino:D

1 to 1.5 bar on suction is fine and 4C is good too (Depending on ambient temperature) I would say that you overcharged it. A tip when you work on cars is that most cars have the refrigerant weight on a sticker somewhere under the bonnet so a good place to start is checking the charge weight by recovering the refrigerant and recharging. Beemers have a green sticker on the bonnet slam with this info.

Auto aircon isn't difficult just different to domestic, I've seen plenty of very good ac guys fall flat on their faces when they've asked me to have a look at a car job that they've been working on for hours and I've sussed it in a matter of minutes, I don't have the heart to tell them that it took me ages to suss it first time I came across it. You get to learn the common faults with each model of car

coolincab
28-05-2007, 09:32 PM
your seat belt locking up ?

momo
29-05-2007, 03:51 AM
Curiosity killed the 'chat' : is "Artisan" similar to "Autónomo" across the ridge (Pyrenees): lots of papero worko and difficulty with the "cobro" (debt collection).
Limitations with employing assistants, sector entry restrictions, etc?

Saludos from "un vâche espagnol"

P.S. "Xccxsxxxnxly a whxlx-sxlxr X dxxl wxth hxs vxn nxt vxnx, hxpx thx Frxnch kxxp thxxr stxndxrds xp wxth thx grxpxs fxr mxny yxxrs" ! hic! :)

Karl Hofmann
29-05-2007, 08:27 AM
P.S. "Xccxsxxxnxly a whxlx-sxlxr X dxxl wxth hxs vxn nxt vxnx, hxpx thx Frxnch kxxp thxxr stxndxrds xp wxth thx grxpxs fxr mxny yxxrs" ! hic! :)

Isn't that the name of a town in the Basque region? Too many "X"s and no way to pronounce them :D

I like the term "Artisan" it sounds as if I should be carrying a paint brush and a canvas :rolleyes:

Abe
29-05-2007, 09:58 AM
Thanks again, I'm self employed here in France, what they call an Artisan, and I haven't been going for long.

I got this job as a spin off from installing 2 mitsubishi splits for a guy this month. He runs a business building dry stone walls with very big chunks of rock and he's got a few of these big machines.
I didn't want to say no when he called me but to be honest I have never worked on automotive before.
Anyway I obviously looked competant because he said I could maintain them all if I wanted.

Now I've been sifting through many posts, often by yourself and I have started to wonder if I'm up to this especially after I gave myself a little scare yeterday. I told my brother in law not to bother to go to BMW for his air con as I was an expert (don't worry everyone in the south of France starts talking like that on a sunday afternoon and after some Pastis and a bottle of wine.
I measure 4°c coming out of the vents and 2bar on suction, down to 1bar to 1.5 bar when he revs up. Too low I say (hick). I added some gas to get the suction up a bit but it didn't have much effect.
Then we went down the drive and when he was breaking it made a noise a bit like something jamming.
We turned back and siphoned off some gas and things went back to normal, but it nocked my confidence. What do you think happened

Expat

Its a good feeling to want to have a go on Mobile, but personally I would stick to what you know best and master it.

In my experience you can get your fingers burnt messing with differant types of systems which are unfamiliar.

But, thats your decision, some people find it easy to move around on differant pieces of kit

Good luck

expat
30-05-2007, 08:26 PM
Yes Momo just as you say lots of paper work. Quite incredible how much they can invent!

Abe, that was good sound advice so I did quite the opposite.:confused:

JCB were good enough to tell me the weigh in charge 1kg-1.1kg, and where to find the suction port. I let in 700gr a little in each port. I then went to fire her up and run the air con. It blew the fuse.

Replaced the 20A with a 15A (It's all I had) and tried with the fan first which worked then promptly blew the fuse again when I switched on the a/c.

I'm now going over the system again checking continuity in the pressostat and anything else I can think of and I remeber I've got some fuse wire in the car. This is where it starts going pear shaped. I've only got 9A wire, so maybe if I double it and twist it a little.

It lasted longer, just long enough in fact for an ominous wiff of smoke to appear and for the electronic screen fuse to blow and for the engine to stop. luckily replacing that fuse put all back in order running wise but my origional problem has become aggravated as now the fan will no-longer run on its own without blowing the (single strand) 9A fuse wire which it did before.

I'm thinking relays messed up, I'm thinking get an electrical schema from JCB, I'm thinking emmigrate back to England, I'm also thinking Abe can smell burning fingers:( .

Oh and I couldn't ask the driver if this had been happening as I turned up way too late- 3:15pm.

expat
30-05-2007, 08:38 PM
And thanks coolincab the suction port was just where you said. Also under the cab was a TEV if a TEV is what I think it is. Does it mean thermal expansion valve? You'll have to bear with me as I learnt all the jargon in French.

Karl Hofmann
30-05-2007, 09:10 PM
Don't forget to check the coil in the ac compressor clutch itself, the resistance should be around 3 Ohms across the terminals (assuming it has two terminals) otherwise from the one terminal to earth.

For the right quantity of wine, I'll be happy to come on down to supervise and advise :D

expat
30-05-2007, 10:19 PM
Thanks Karl but this brings me back to a bugbear: trying to understand electricity properly.

If we want a given amount of work produced with a certain voltage we appo(stop me if i'm rambling i'm making this up as i go along)se it with a certain resistance, so if i'm working with 24V does this mean the resistance should be halved or will it be the same resistance but drawing half the amps it would on a 12V system?

And if you do come to supervise bring a deck chair as were in the hills in the middle of no-where surrounded by green vine fields and silence ;) (oh, and three dirty great excavators).

expat
30-05-2007, 10:28 PM
For the right quantity of wine, I'll be happy to come on down to supervise and advise :D

You know, we're fridgies and we do acid test - small amount of oil and we're looking for a certain colour. With wine it's much the same except the small amount bit. With wine you need to test gallons and you're only good at it when you find that certain colour, i.e. your nose has gone purple:D

clivemtk
30-05-2007, 11:01 PM
tried all kinds of dyes and leak fluids on transport fridges try going to shop get some fairy washing up put quarterin spray can top up with water spray condenser have a cig watch bubbles appear but it has to be fairy liquid

expat
06-06-2007, 03:08 PM
I found the problem with the fuse blowing. Someone had wired the compressor up with the plus, coming from the switch, going in and the minus coming out and attatching to the compressor casing. The minus, then however, came away from the casing and was spliced back into the plus.:confused:
Unfortunately the wire coming from the switch in the cab and going to the compressor coil was only 1mm² and did not survive the current that the 20A fuse let through before blowing.

The insulation burnt off the wire along nearly it's entire length and burnt some wires near it.

Here are a couple of photos
1537

1538