Mysterious yellow goop where heater hose connects


#1

I have noticed an occasional spot of yellow colored goo on a heater hose. After I changed a clamp on another heater hose, I see today that there is yellow goo on the metal where that hose attaches. No coolant came out when I changed clamps. Anyone know what this is? Thanks.


#2

what color is your coolant?


#3

Prestone green


#4

It may be a grease used to lube the connection when the hose was attached.


#5

I do not grease coolant hose connections. One person said that is how air interacts with the green colored coolant. also that some coolant is ethylene glycol based and others he said were silicone based. The oozing directly from the other hose he thought to be pinhole leaks in the new hose.