Originally Posted by theworld
-X26 Bus from East Croydon (however not sure about timing, I think there is a bus at 06.04, but it takes 68 minutes according to TFL, and then I have to get to T4)
-Train to Clapham Junction then bus to Hatton X (however can't remember the bus number), then bus to T4
I think the X26 goes to West Croydon (at least that's what it says on the front of it when i've seen it at Hatton X) - so i can't comment on it .. i'd imagine it must be prone to traffic issues though - and it doesn't seem to be very frequent.
I'd take the train - a fast train from East Croydon to Clapham Junction takes ~ 10 minutes. At Clapham Junction change for a Feltham train (usually go from Platform 6 I think) - there are 4 per hour so you have to time it. Train takes ~20 mins to get to Feltham. Hop on the bus at Feltham (#285 they're pretty frequent and go from just outside the station) which will take you to Hatton Cross where you can jump on the Tube to T4
(Edited to add if it's this Friday the Tube from Hatton X to T4 won't be open - but you can take the replacement bus)
A little bit convoluted but it's the fastest way I think (and probably cheapest too - you can do it all on a Zone 2-6 travel card)