Replacing a seal - JCB mini digger

[Goodwill Man]

Gentlemen,

On my mini digger JCB 8014, I’ve noticed that one seal is not properly positioned. See the photo. It looks like it has been pushed out on one side. It started to leak a bit. I tried to push it back into position, but no joy. It is too hard. In my area (near Heathrow airport) there is no mobile JCB service, so my intention is to replace that seal myself. However, I have never done before. Therefore, I am seeking some advice on that matter.

Do I need to disconnect the hose (presume YES)?

Is there any fluid pressure in the system?

How do I re-fill the system after repair and reconnecting the hose? Is any air bleeding procedure required?

Are there any special tools needed for that job?

Any advice will be much appreciated. Cheers

 

[doobin]

You'll need to remove the ram. No pressure in it when digger is off so long as you park it right (depending on the ram). No bleeding required.

Any hydraulic repair place can sort it easily, or you could get the seal kit and do it yourself but you will need a proper strong vice and the right c spanner (or ability to make one).

There must be a hydraulic place near Heathrow, that's by far the easiest if you don't have a decent workshop yourself.

 

[Goodwill Man]

Hi, thanks for reply. I think, I will take up the challenge. I will borough the big Monkey Wrench to undo the seal cup. Now I am sourcing parts need.

 

[Smiffy]

Hi, thanks for reply. I think, I will take up the challenge. I will borough the big Monkey Wrench to undo the seal cup. Now I am sourcing parts need.

It's easy enough to fabricate a pin wrench using a piece of flat bar and angle grinder.
Then you have it for future use of any others go.
Don't use any for of pipe wrench that grips the outside as it will just make a mess of the casing

 

[Rob65]

If you are going to have a go at doing it yourself pull the pin to disconnect the rod end from the machine and then use you pin wrench to unscrew the cap.
By leaving the pin in the cylinder end you don’t have to worry about how to hold the cylinder whilst you get the cap unscrewed as it’s still attached to the machine.

Having got the cap off you can pull the rod out but then your next problem is how to get the piston nut off. They can be very tight and you must not mark the chrome by gripping it in a vice for example.

Please let us know how you get on as I have a similar one to do that I have been shying away from for too long
.
Rob

 

[Goodwill Man]

Sure, I will report when done. Now, I am trying to buy the seal kit, but having problem to identify the correct seals. Surprisingly, many JCB parts suppliers don't stock them at all. I found few on Ebay. But first I need to take the old one out. I will make my own pin wrench as suggested by mr. Smiffy.

 

[T whiting]

If it's not a front line machine I'd take it off and take it to your local hydraulics place is normally the simplist and my local one isn't overly expensive.

If you do it yourself make sure to use a pin spanner we had one taken to bits with a pair of sthilsons and it squashed the cap and never sealed again.

You can pin the rod back to the dipper to hold it without marking it but be prepared you will probably need a 6ft scaffold tube on the socket to get it to move and there might be a pin/grub screw/tabs holding the nut on.

You might need a pair of circlip pliers to get the seals out some have clips some have the wire type that you have to get out with a screwdriver/pick

You also need to check the rod is free of damage and not bent though that's more of a concern if it's leakingrfarther than a seal that's popped out.

I've attached a couple of photos of one I did on the little komatsu just to give you a idea of what your heading for

 

[V8Druid]

wire clip type ..... have to push the end cap back in to reveal it

once the clip is out a bit of air will push the rod and end cap out .. make sure you retain it all as it'll pop out pretty quick

this piston had a grubscrew retainer

and screws off so you can slide the end cap off to get at the scraper seal, bearings and gland pack

I hate ppl who use loctite on these

and that's a tiny cylinder
this type are even worse .....

and usually need the loctite cooking out ..

pin spanner making up if you don't have an adjustable one

and this one pulled out ok .... just

pin retention on this was

 

[V8Druid]

butchery

drilled to clear

to punch out

nut off and piston slides off

followed by the gland block and end cap
so that's a couple of variations for you ... some sneaky so and sos hide a retainer pin/grub screw under a seal on the piston .. IIRC jake are famous for it

 

[AusDave]

Just be aware on some JCB rams, the piston nut has a locking pin going through the side of the nut into the shaft. The pin is a drop in close tolerance fit and if you don't look for it you may miss it and spend time applying extraordinary force to unscrew the nut to no effect.
Mine had a 3mm thread in the pin and by screwing in a small screw with the correct 3mm thread you can extract the pin easily and the nut will come off easily as well.

 

[Flying Torquewrench]

JCB Parts - The Official JCB Parts Store

Genuine JCB parts available online, pay by credit card or Paypal and get them delivered direct to your door.

parts.jcb.com

-Follow the link above.
-Where it says “enter part number or machine pin number” enter your machine’s serial number.
-Select the right seals from the menu.

It will also give you an exploded diagram of the cylinder so you know what to expect. I have a 8016 and changed the seals a couple of times, a relative easy job to do.

 

[CPS]

Just be aware on some JCB rams, the piston nut has a locking pin going through the side of the nut into the shaft. The pin is a drop in close tolerance fit and if you don't look for it you may miss it and spend time applying extraordinary force to unscrew the nut to no effect.
Mine had a 3mm thread in the pin and by screwing in a small screw with the correct 3mm thread you can extract the pin easily and the nut will come off easily as well.

This is a very important point! be sure to double check the piston nut to be sure there is no grub screws or locking pins holding it on