1989 JCB 3CX Brake Pipe Replacement

[cby2k1]

Just wondered if anyone had done it / has any advice on replacing the brake pipes on an '89 3CX Grey Cab. Realised at the weekend that I've got no brakes. Right pedal goes to the floor with no bite, left pedal will bite when pumped but fades. On closer inspection looks like the LHS has been leaking to the point where the fluid is now below the minimum - although both sides are under the minimum now so i'm guessing the right has also leaked out at an earlier time and I didn't notice as the pedals were connected.

It seems straight forward enough to replace - although getting to the place where they go through the floor seems like the biggest challenge. I'm wondering whether it might be as easy to just replace the full length of pipe on both sides including the join and part inside the cab (parts 7,8,9,10,11 in the diagram). Rather than trying to unscrew the pipe from the join where it meets the floorplan

 

[craig]

When I had my 3cx, I just changed the brake pipes under the cab, the section inside was in ok condition. They bleed through fine by gravity (slacken the bleed nipples off and let the fluid run by its self until there was no bubbles coming through), but I seem to remember it wasn't normal dot 3/4 brake fluid, but something like a light hydraulic oil, can`t remember to be honest. I see if I can dig out it`s manual and check.

 

[craig]

If the inside pipes want changing as well, I can`t see a problem doing them in one piece.

 

[Left hooker]

When I had my 3cx, I just changed the brake pipes under the cab, the section inside was in ok condition. They bleed through fine by gravity (slacken the bleed nipples off and let the fluid run by its self until there was no bubbles coming through), but I seem to remember it wasn't normal dot 3/4 brake fluid, but something like a light hydraulic oil, can`t remember to be honest. I see if I can dig out it`s manual and check.

Yeah light hydraulic oil any of the dot stuff will fit the seals

 

[cby2k1]

Finally got around to taking the two brake pipes off today, easy to remove from the axle but a pain in the backside to reach the other end as it sits just below the pedals on the underside of the cab. I decided only to replace the damaged section as nothing wrong with the pipes inside the cab and actually the joint is attached to the floor so it would have been a real pain to get that off - it was difficult enough to reach the location in the first place!

The LH pipe just snapped off as i turned the nut to remove it on the axel, the RH pipe managed to stay intact but interesting that both failed at the exact same place, and around the same time.

The hard to reach location (you can just make out the thread on the adapter where i've removed the two pipes)


The right hand pipe leaking in the same place and the left hand pipe that snapped


This is the left hand pipe in full - minus the snapped off end.