I have a 94 f150 4.9L and whenever I drive I look under the hood once im done (because i just had head rebuilt and check on it regularly) when i lift the hood there is coolant on top of the reservoir the reservoir is alittle bit above the cold fill line so i thought it could have been splashing around but the other day when i looked its still at the same level and there was coolant still all over the outside of the reservoir so i checked my radiator and it was low but my truck has not been overheating and has been staying under the N in normal on the gauge i filled the radiator and had the cap checked and it was at 13psi like it should have been what could it be? its still all over my reservoir and its new coolant every time i drive it cause i wipe it off...

 

Get a new cap on general principle. If this doesn't fix it, look elsewhere for leaks, something is sucking air somewhere.