Skydrol is fire resistant and pretty hard to ignite let alone sustain a flame.
GE90 PW4000 EDPs are under the t/revs attached to the accessory g/box, there is a titanium heat shield to prevent any combustable fluids spraying on to the hot section and protect the g/box from heat.The area is cooled and ventilated by fan air and LP compressor air.
Trent EDP under the fan cowls - area cooled and ventilated via ambient.
Engine hydraulic fire?
I'd doubt it.