It looks like the small hose (1 ½ od X 1 ½ ) between the thermostat housing and the cylinder head needs replacing. Will I be able to cut this out and slip a new piece in without taking the water pump out?

No, you need to remove the water pump.

jack

Read what Benzmac had to say in this thread about replacing an M103 water pump. There's alot of info on this subejct in the archives.

http://www.peachparts.com/shopforum/showthread.php?threadid=6640&highlight=smear

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Thanks Mike,

I'll look in my box for flx13...

I mentioned this before, do a search.
Anyways, here it goes...
I slipped a new one, without removing the water pump. NO tool needed. The secret is to use the MB hose (less than $10), since the OE aftermarket is too stiff.
The procedure is as follow:
1. Release the clamps and remove/cut the old hose.
2. Use a lot of vaseline or grease and cover completely the new hose with it.
3. Push, pull, cry, swear and then stick the small end first in the small opening between the cylinder head and the thermostat housing. The big end will just follow.
4. Use new clamps and then you are done.
Good luck!

__________________
J.H.
'86 300E

That's what I wanted to hear... I'm stubbron I rather cry also

Thanks JH

Let us know how it went!

__________________
J.H.
'86 300E

I picked up the hose from the dealer $5.10 I get a discount One dealer wanted 14.00
I noticed references to Mercedes antifreeze. The antifreeze looks nice and clear but I was going to change it out. What is the proper product to use? (I have a few gallons of Prestone). I thought I read something about 50/50. How much does the 103-system hold?

I do remember I only got one bottle of antifreeze. I mixed some in a separate container 50/50 and THEN I poured it in the car. Little by little until full.
As far as the brand, well... I think everyboyd will have a separate opinion on this subject (just like synthetic or dyno oil). I used valvoline 5 years? antifreeze. It works for me. Just change regularly.
By the way, do not forget to empty the engine block at the same time. There is a plug under the exhaust manifold, towards the rear, you probably will need to get to it from under the car.
Good luck!

__________________
J.H.
'86 300E