Need a hose part number

I have it patched somewhat, and zip tied it back in place. However for the life of me I can't find out which frakkin' hose this is. It runs out of the top of the auxiliary water pump, and down to the bottom of the water pump on the front of the block. It has 0191.r inked on it, and GH1 11 etched in it. Neither returns a part in searches. I've included a picture crudely marked by an arrow for reference. I'd like to get this thing identified, and have a source for purchase ASAP as I don't like the feeling of driving around with a patched hose. Much thanks to the resident CLK gurus.
sorry to jack this thread, but eaelier i asked you for help about the water pump. got it replace and the guy at the garage said the fan clutch needs replacing. is this normal, because the fan was working fine, it'would come on when the temp got high. how much did this part cost you? do you have the part # too??
TIA
will







