Offroad-Express

Hi guys. Newbie here, so go easy

I'm 99% sure I have fuel leaking from the plug (adjustment nut??) that lies in between the fuel lines where they attach to the injector pump. (See blue arrow on attached photo. Note: This is a borrowed sample photo and not my 'actual' pump).

It is leaking around the edge where the plug?? screws into the manifold??

1). What does the plug do.

2). Is it an easy fix or does the whole pump have to come out?

Any advice would be appreciated. Cheers!

P.s Is D21 the same as WD21??

Hi - that plug is exactly that - a plug. It has a knife-edged (built in) seal at the business end of it which seals off the high pressure side of the pump plunger. It also has a rubber O-ring under the head of the plug but that won't stop a high pressure leak if the knife-edge is letting fuel past it. As you can see it is a triangular shape and needs a special socket to remove it. It is unusual for a knife-edged seal to suddenly start leaking so you need to be 100% sure your leak is coming from there as fuel can "track" all over the show from a leaking injector pump and it is often tricky to pinpoint the exact source. But to answer your question - the plug can be removed without taking the pump off but you do need the special tool and you'll be very lucky if any fuel injection workshop will lend you one. The plug needs to be pretty tight too so it's not worth naffing about with pipe grips etc it only leads to tears! Those plugs are intended to be once =-only use and are almost always replaced when pumps are overhauled. Hope this helps - but probably not much! Cheers - Rod Oh yeah - forgot to mention- the 12mm bolt in the centre of the plug is easily removable. You can replace the 8x12mm copper washer on it in case it's leaking from there. It's the bolt you remove to fit a DTI gauge in to measure the plunger stroke when timing the pump to the engine.

aidytheace wrote:Hi guys. Newbie here, so go easy

I'm 99% sure I have fuel leaking from the plug (adjustment nut??) that lies in between the fuel lines where they attach to the injector pump. (See blue arrow on attached photo. Note: This is a borrowed sample photo and not my 'actual' pump).

It is leaking around the edge where the plug?? screws into the manifold??

1). What does the plug do.

2). Is it an easy fix or does the whole pump have to come out?

Any advice would be appreciated. Cheers!

P.s Is D21 the same as WD21??

image.jpg

aidytheace wrote:P.s Is D21 the same as WD21??

W indicates Wagon, so any Pathfinder/Terrano is a WD21. "Model D21 Series" is the designation for the Hardbody / Navara minitruck platform on which the WD21 is based.

Cool blue arrow.

lax2wlg wrote:

aidytheace wrote:P.s Is D21 the same as WD21??

W indicates Wagon, so any Pathfinder/Terrano is a WD21. "Model D21 Series" is the designation for the Hardbody / Navara minitruck platform on which the WD21 is based.

Cool blue arrow.

Cool hand model

Mine was leaking in the same place, I wound up removing the pump and putting a full seal kit in it. For that plug I used a tight fitting 12 point socket tapped on onto it, worked a treat as the plug wasn't very tight.

I've had success in replacing the o-ring around the outer diameter of the bung. With correct socket its easy to remove (is very tight, so can't imagine it coming undone without 3point socket)
You'll also need the correct size o-ring.
Its a pretty simple job for a fuel shop to do, so for a one-off I recommend taking it to someone with the gear.

Best way to know for sure exactly where its leaking, is to brakeclean it immaculately clean, then watch the fuelpump as someone else starts the engine.
Keep eye on fuel tracking down, and double check there's only the one leak.

Thank you for all the advise and info guys! I spent some time yesterday degreasing the area, then using compressed air to further clean and dry everything. With an inspection mirror and torch, while someone started the truck I am now 99.999% sure that its coming from the plug o-ring/seal. I don't have the right tool (3 sided socket) so I'm thinking a trip to Diesel Services is in order.

Thanks again!

slide wrote:I've had success in replacing the o-ring around the outer diameter of the bung. With correct socket its easy to remove (is very tight, so can't imagine it coming undone without 3point socket)

Did you have to remove the pump first? I'm just wondering if the plug can be serviced while the pump is still attached to the truck?

Yay, got the plug replaced $130 + gst and the leak is fixed!! Thanks again for all the help. Cheers.

aidytheace wrote:Did you have to remove the pump first? I'm just wondering if the plug can be serviced while the pump is still attached to the truck?

Yep in place. Bit tricky to get around fuel lines, but do able.

aidytheace wrote:Yay, got the plug replaced $130 + gst and the leak is fixed!! Thanks again for all the help. Cheers.

Awesome, glad to be of assistance