I just spent half of the weekend changing the stat on SWMBOs TD4, not because of any temperature problems but because it was leaking coolant. I was pretty difficult and I made a mistake with one tool so I thought I would post some pics and tips.
This was the reason for the leak:-
the seal was pinched, I think as a result of a stat change by a previous owner.
A previous poster suggested undoing the last bolt on the tube and the pulling the tube back towards the brake master. I would say that this is essential. If you crawl underneath with your head past the antiroll bar you can easily see it here:-
I used a tool like this:-
and by sticking just the hex bit into the bolt I could then see it looking through the inner wing (hole for the track rod end):-
that's the hex end of the bit, then it was simple to push on the ratchet handle and undo it.
I used a luggage strap in a loop around the pipe and the brake master to pull it back.
The mistake I made was to think that I could do this job with an E8 ratchet spanner and an E8 3/8" socket, but you can't. You must have the E8 ratchet spanner, and the E8 socket
must be a 1/4" inch drive like this:-
because a 3/8" socket is too big to fit here:-
and the ratchet spanner won't go in there either.
I jacked up the engine and removed the top engine mount, as suggested, and also ran a ratchet strap from the bottom engine mount over to a spoke in the nearside front wheel and then pulled the engine over a bit away from the right and side inner wing. I think it only moved a few mm but even that is a big help.
lastly I gave up trying to remove the hose from the thermostat, instead I unclipped the other end of the hose and pulled the stat out with the host still attached, moved the hose over to the new stat, and then put it back in with the hose already on:-
I doesn't seem to leak now