Questions regarding a JCB I’ve just aquired

[Trevelyan]

Hi, I’m new to this forum as I have just been given a 3c111 JCB, I have millions of questions but will start with just a couple to avoid confusion (on my part !)

So this 1978 model according to the low loader driver and the plant fitter who managed to drain water from fuel tank to get it started both say its one of the better ones they have seen,although some of the usual problems are there namely the cab rusted out and brakes non existent as I found out when I stopped on the hill up to my yard !!!

So first question is....the hydraulics ...all works when level, but when digger is on any incline it does not work....ives topped up with hydraulic oil but still no go...I tried bleeding pump and there was air and also when I opened filler , big mistake as it blew out into my face and everywhere as I stupidly did it while it was running!!! It was very milky and looked aerated. When levels bookmark and loader works and feet can lift back wheels off the ground...digger has been sat a while....Any ideas and what should I do to service it all? Anyway to test if its running correctly etc etc

Also one tyre is flat ,if its not tubeless can one go in ? The others are pretty new...


The hand brake is seized not that it stops it rolling back!! And the 2 pedals on the floor don’t seem to do much ,is there any info such as maintenance manuals I can download from here as I’m gonna get my REME tool box out and tackle a few of these jobs......

One more thing, when I connect battery putting earth on last it goes on no sparking and when start button is pressed it starts first time,but then once disconnected and connected it arcs and an electrical motor sound comes from starter, not engaging but a smooth motor sound, and vehicle cant be started...I’ve never left it connected like this in fear of burning something out...this happens for a while then after 5 or6 tries at connecting its gone and I can start digger..


That’s the main problems and any help answering these will be greatly appreciated...even better if any of you boys live in Cornwall as I’d love to come pick your brains or pass you some work ...


Will add photos as soon as it lets me!regards Steve. Perranporth

[Jeremy Rowland]

Hi Steve and welcome you have your hands full there but still have a great old classic; sounds like your JCB has stood for a while and you may have water in the hydraulic oil as you said it is 'milky' I would change the hydraulic oil and filter, when you say the hydraulics don't function on an incline do you mean any of the hydraulics or just the back actor arm?
There are many threads on these machines so read your way through them plus there is a wealth of knowledge on here so people will eventually answer your questions.

Jeremy

[McPaddy]

I have a JCB 3c of a similar year (1975) and I have VERY little hydraulic oil and what I do have is milky so I'd be interested to hear the procedure for a full fluid change!

[Trevelyan]

Hi , thanks for the reply ...yes none of the hydraulics work , front , back or feet when on any incline but as soon as you level up they work again ....I did top it up but as you say it seems contaminated and as a matter of course I will service it ..,but despite this problem the system must be ok if it works when level and like I mentioned the feet had enough power to lift both rear of the ground ! Just curious about the incline causing it to stop working totally , can’t get my head around it ...

[Trevelyan]

Also I can’t upload pics for some reason , it starts and blue progress line goes a quarter and stays there forever ...

[Jeremy Rowland]

Steve I can't help thinking that somehow you don't have the correct oil level in there so when you are on an incline the pump is starved of oil? I'm no expert on hydraulics or JCB; I seem to recall there is a sight glass on the side of the hydraulic oil tank have you checked this?
The only thing that I can think of as said is oil starvation that can only be caused by a low oil level or a blockage such as a clogged oil strainer? Does the machine work if it is 'nose down' on an incline, in other words with the front shovel pointing down the slope? Because the pump is driven off the front of the engine, technically the pump should suffer no oil starvation?

Jeremy

[Trevelyan]

Cheers for reply and I was thinking the same ...it’s just I too it right up beforehand , maybe there was an air lock , I don’t know ..
No I only tried on an incline with big bucket in front ..was not going to reverse up the lane , was hard enough controlling it forwards as one big tyre was flat ! Lol
What about the starter problem ??

[Jeremy Rowland]

Cheers for reply and I was thinking the same ...it’s just I too it right up beforehand , maybe there was an air lock , I don’t know ..
No I only tried on an incline with big bucket in front ..was not going to reverse up the lane , was hard enough controlling it forwards as one big tyre was flat ! Lol
What about the starter problem ??

Steve electrics are not my strong point but it sounds to me like something is shorting down to earth, sorry but that's all I can give you.

Jeremy

[essexpete]

Starter sound like it is spinning but not throwing in. Probably due to lack of use.
Re The hydraulic oil can you see the oil in the sight guage? They do hold an enormous amount. Like Jeremy suggests there may be a lot of sludge on the main filter in the housing on the right side.

[Trevelyan]

And I’m assuming you got to extend everything to get true level ?
The starter does work but every now and then as soon as I connect batter it spins ... still can’t upload pics !