I would not use any RTV there. It can cause the hose to spit off the fitting when under pressure. Something like a hardening Permatex (#1, I think) would work better, but will make future service a nightmare.

You shouldn't need anything but the rubber inside the hose.

Is it possible that the wider-than-original hose clamp is overlapping the bead on the pipe? (Which is not to say that a narrow clamp could not do the same thing.)

alright, so the consensus is to NOT use RTV in this situation. we've got one vote for a more permanent solution if i'm going to go gunking things up. which, in my cynical little world, would pretty much guarantee that something would go wrong to make my permatex job a problem and not a solution.

so then.......

let's say i get home from work today and clean up the connections, slip on new hose clamps, clamp the heck out of them, and i STILL have a leak? then it might be a cracked hose coming from my firewall? what about the thermostat housing connection....cracked too? anything else cause these sorts of issues?

thanks!

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

that was my original thought that had me detaching and reattaching the hoses a bunch of times, trying to make sure the hoses were placed exactly right before the bead on the pipes. i'm pretty sure i covered all my bases there unless the clamps no longer clamp true all the way around. i'll be picking up a couple new clamps after work just to be safe with that issue.

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

On my car the corrosion bumps were obvious, you could have them on the underside of the nipples. Anyhow, if the nipples are clean and not deeply pitted the hose will conform to its shape.

alright, so i picked up a couple of new hose clamps and got to work after work.

the hose on the firewall: took it off and cleaned the nipple. no build up or corrosion or bumps, smooth and clean. possible warpage on the clamp, possible clamp on at an angle. put on a new one and tightened the heck out of it at hopefully a better angle.

upper radiator hose at the t-stat housing: noticeable gunk and build up. chipped it away with a razor blade and scrubbed it until it was much cleaner. put on a new hose clamp at a straight angle. refilled, burped, driven to temp. and now left to cool back down to find out in the morning if things are any better.

i was hoping for a more obvious discovery. we'll see.....

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

My experience (FWIW) w/this sort of thing is as follows :

DONT BUY HOSES ANYWHERE BUT AT MB DEALER.

The hoses sold by worldpac, ect.. dont fit correctly. I went thru this bull***** once with the upper rad hose (easy to change) and onec with lower rad hose (PIA!). Had to remove both and go to dealer, and found the hoses fit much better from MB. Leak stopped. Worldpac is yet to refund my lower hose ($60) because they said I used it. You try getting that thing on and off the water pump housing without "scuffing up" the stick on label. It has ZERO miles on it, it wouldnt even hold coolant as I tried to fill it. I love most stuff from WP but not hoses for MB. They dont have the fit correct and dont seem to want to bother with correcting it.

Just a rant, sounds like your leak is fixed and I dont even know if you were using OEM hoses or not...just felt like *****ing since my knuckles are still scraped up.

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Paul
Benz-less
I need an SDL !

I just replaced all of my coolant system and heater hoses ('82 300D) last week with aftermarket hoses made by CRP. I had no issues with fit or function on any of the 12 hoses.

The ill fitting hoses world pac sold me were made by Elaplast (which they claimed was OEM).

Im glad you did not have the same experience, hopefully the aftermarket has their ***** together w/617 more than 603.

Sadly for me, the difference in price between Worldpac and the MB dealer was negligible. If my time was worth anything, I lost big $.

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Paul
Benz-less
I need an SDL !

I went through the same scenario and found the opposite conclusion to be the situation. The WorldPac upper hose for the 617 was about 1/2 the wall thickness of the original hose.........so thin that the complicated bend caused the hose to kink slightly on the install. Apparently, they didn't get it perfectly manufactured.

So, I go to the dealer and order the OE hose. I bring the WorldPac hose with me when I go to pick it up. What do I find..........and identical POS hose from the dealer.

I take the original 22 year old hose and reinstall it.........it's got to be better than this garbage........from either place.

so after a loooooong days drive all over the ithaca fingerlakes area i parked the car to cool off over night. in the morning i discovered.....NO leaking from the firewall hose and NO leaking from the upper radiator hose at the thermostat! BUT there was leaking from the top of the bypass hose AND there was still some pressure in the system after it had been parked for around 18 hours. i have a spare thermostat housing gasket laying around, i might pop the bypass hose off and clean and re-clamp that one as well, just to see what happens.

this is getting very frustrating though, and making me question my cars reliability. i want this to be fixed! and i want to stop dumping zerex into the damn thing as i have to buy it by the case!

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

Have you replaced the expansion tank cap? They do fail also, either by holding too much pressure, or not enough.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D

yeah, the cap is new. i feel like after i put it on it holds too much pressure. 10 to 1 i threw out the old one so now i can't test this theory....

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

so today i got around to doing some more work. i completely removed the thermostat housing from the car and found it to be completely gunked up around the ends of the hoses. i took a wire brush and a razor and scraped it all off, washed it, and reattached it. while it was off i noticed a pretty good sized chunk taken off of the edge of the hose going to the upper radiator hose. it's about an eighth of an inch in diameter and sits right in the middle of the lip on the hose. i have concluded that this, coupled with the gunk, has led to my leaks. i re-clamped the hoses and filled it back up. it keeps perfect temp and didn't leak on the drive to bring it back up to temp so i've got that going for me. tomorrow morning will be the real test to see if any leaking occurs.

if it's still leaking from the upper radiator hose i think i'll have to buy a new themostat housing.

the leak from the firewall has stopped completely, it just took some clamping and re-clamping to get it right i guess....

as for all the talk of the hose quality, i got all of mine as a kit from another parts source online. all of them seem like great quality EXCEPT the upper and lower radiator hoses are definitley thinner than the originals.

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

alright, i think i'm done. cross your fingers. so:

thanks to daw_two i got a new thermostat housing. perfect condition and by the smell i believe he cleaned it for me with some kind of solvent. a very cool extra touch, i thank you and tip my hat!

with no real troubles i switched in my t-stat with the new housing, plus my vacuum plug. screwed it all back together every which way and filled it back up. no immediate leaks, took her up to 80* with no issues, burped her a bit, and drove her back home to rest. the real test comes tomorrow morning when the car has cooled down enough to shrink and leak. we'll see.

i attached a few pics of that hole/chip on my t-stat housing lip. who knows what happened but it didn't become a problem until i switched out the hoses. look carefully!

thanks for everyone's help and daw's used parts!

Attached Thumbnails

     

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)