Injector pump 2.7td Terrano.

Have a leaking one on this vehicle ,are they hard to exchange !,looks awkward to get at. Can some one tell me are they gear driven or chain driven,! Job for a competent home mechanic or take it to the garage!. Any advice appreciated. Thanks.

I've never done one, but they are awkward to get to. You would have to pull the mainfold off at least. What part is leaking. You might be able to just fix that leak in place. Sending the pump in to be done won't be cheap! I think that these pumps might be belt driven! I'm not sure how they are timed, but I guess the place that rebuilds your pump will be willing to tell you how to time it. I'm not sure how competent you are, no offence, since you are asking how to do it, but I wouldn't think it would be too bad of job to be done at home. Just a matter of stripping bits away so you can get to it, making sure you don't introduce dirt into the system, and correctly timing it all up.
Might pay to consider running Diesel additives in the future.
p.s. I wouldn't be that keen on a second hand pump, unless it's cheap. You could put it in and a few months down the track, that could start leaking too. If you do go for second hand, at least send it in to a specialist and get it checked.

Most of the leaks that happen are just O rings and some of them can be done in place.
Give it a clean and a wipe then start it up and watch to see where the leak is coming from. It might be something real simple.

They are driven by a gear in behind the timming covers. Theres a plate your remove infront of the injector pump to access the gear. You have to line up the marks which are letters. Ive fitted second hand pumps twice and both have leaked straight away so I wouldn't go down that road. It has to be timed up on the gear then have the plunger on the pumptimed up. Its not really a home mechanic job id take it to the workshop. As other posters have said they might steam clean it and find its a easy to get at seal. If nits a pump removal job make sure you get a quote so you know what your in for.

hi 3 zzz 2 on main gear 1 on pump gearif its leaking out the top cover or on the side of the pump away from the block it can be done in place if not pump off call if we can be of any help as we do these almost weekly cheers phill

if you do it your self then delete the egr while your at it and clean out the intake manifold as it has to come off anyhow to change any seal on the pump.
steamclean the engine first as you have to work clean round injector pump.