Heater hose near firewall blew today!!!
 

As I was driving up the 57 in Glendora, Ca., I noticed white steam or smoke coming out of my hood this morning (panic!).
I took the next exit and pulled over, lifted the hood.
All of my coolant (well, it seemed like all of it) had spurted out of a hose that comes from the fuse compartment side and goes into the back bottom side of the engine.
Steamed for quite a while before I could see well enough to what was going on down there.
The hose had split right before the hose clamp going into the engine block.
I used some duct tape and drinking water I had in my trunk to get me to Autozone and spliced in a new elbow, filled with coolant (1.5 containers worth) and was good to go.
Before that I noticed I was losing coolant a little at a time so maybe it was coming out of that area.
You may want to check this on your 300E or carry a small hose repair kit and elbow hose just in case.

In addition to the hose mentioned above. I would advise anyone with a M103 to replace the heater hose that is present next to the battery tray from the firewall. When doing an inspection and cleaning out leaves, I noticed that over time, some battery acid had found its way onto the hose and made it extremely tough and almost porous looking to the eye. Replace it!

How Old ARE YOUR HOSES?
 

If you're running 10 to 15 year old hoses ,YOU do enjoy High Risk Games !

Thanks!
 

I am running original hoses on my 1989 300E! Better check them out and replace!

Question...my downshifting is kicking harder than normal now. Could coolant from my leak have gotten into my transmission and be causing this? It starting happening right after this happened and most of it pressure leaked out right over the trans...Acceleration is normal.

...found out after I bought new Trans Filter and Fluid that my vacuum line to transmission had just pulled out (probably from me repairing heater hose). Trans downshifts shifts fine again. Returned everything:)

'91 500SL
 

I am trying to replace the heater hose on my 500SL. I have removed the windshield wiper motor and the other three bolts holding the plastic pan below it. I am trying to remove that pan to get to the top portion of the heater hose but I still can not get it to come loose. Is there something that must be disconnected that I have missed? I am at a loss.:confused:

Is that the same hose on the back of the m104? I had that p
O ring leak then the bolts stripped off. Huge pain in the ass. Basically I had to remove the head to fix