Take the standard tools with you, some extra tires, a pomp, tape and if needed a set of extra elastics for the breaks. This should help you out in about 85% of the time.
Besides that; contact your local dealer. While a lot of companies state they can 'deal with any chair', my experience is that they can sometimes and sometimes can't. No prob. with the can't, but big problem with the can't if I see them messing my chair up. Or better said; trying to, as I'll stop them right then and there. Your local dealer can tell you who to contact no matter where in the world you are.
For really anything WDW will be great. They'll help you out where possible, whether it being fixing it rght then and there themselves, by somebody else, getting you parts you need and/or getting you a back up chair or
ecv while your own is down.
I've had it happen to me. My powerchair was handled like dirt and damaged big time during the flight down. Damaged parts, no functioning battery charger, boy was I in for trouble! NWA sent Florida Mobility 'round for some "fixing". Ahum. First of all the guy started lashing out about my manual chair with info which simply isn't correct. Well, touch my chair and you touch me, so that wasn't too good of a start. Florida Mobility claims to have knowledge of and experience with the Permobil chairs, which unfortunately I've got. However they totally failed to recognize the problems of the chair and totally misdiagnosed the situation. OK, can happen, right? Well, it makes me wonder how good you are at what you do, if you don't even see standard big parts being crushed and jammed at places they shouldn't be at if you looked right at that spot on multiple times. Add up that they were very unclear about when they would come round -which prevented me from going to a park- and it ended up with 'we'll come in the morning' and them coming at 6 pm....... I'm not a Florida Mobility fan, let's put it that way.
Disney on the other hand; 2 big thumbs up. They noticed me struggling with NWA big time and jumped right in and saved the day. They tracked down Permobil USA and arranged for me to get a charger so I could at least go somewhere. They went to Brownings for me and delivered it to my room quickly. They checked back about that twice, first to make sure I got it and second to make sure it was the right one.
Hearing about the parts being broke, they offered me a free ecv via the WDW-rental. Finding out that I really need a powerchair, they offered to get me a offsite rental one. I declined the offer as I need my own seating-system, but really appreciated it.
The rest of the week they kept making sure there wasn't anything I could possibly need. I could hardly get past a CM at OPR without somebody striking up a conversation about what happened and asking if there wasn't anything they could do. One last surprise they had in store when I asked for a print out of the balance on my KTTW-card. I just wanted to see how much I had spend and found out that there had been a charge on there for a batterycharger, which had been credited right again. Asking about this at Custom House informed me that CBR refused to let me pay the bill and payed for it themselves.
A wc breaking down is not something anybody will ever look forward to. But if it ever has to happen while your not at home, WDW is a great place for it to happen.