My friend and I are in the middle of swapping the engine from my dad's 77 240D auto to his 83 240D manual that had a bad engine. It's been a long job because of the floods that have come from the sky here in Atlanta the past few weeks and getting set back a few times. Newest setback is that we didn't think to buy a pilot bearing and are waiting for that.

We took off the upper radiator hose when removing the engine and inspected it to see if it needed to be replaced. This is what it looked like, sorta dirty but the rubber is in excellent shape, looks like it could have come out of the factory yesterday besides being as dirty as it is:



No surface cracking, softness, or anything that would indicate that the hose needed to be replaced. We saw it had Mercedes markings on it so we looked for a date code and this is what we found:



January 1977. Original hose. 38 years old and still great.

Unfortunately the lower hose wasn't in quite a good shape but it was twisted around quite a bit when we were removing the engine. Surprisingly, a local O'Reilly's had a Gates hose in stock for $21.

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Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.

I'd replace it on principle. Rubber degrades after 10-15 years no matter what. The MB rubber seems to be really good (wish I could say the same about the damn plastic) but it's still rubber.

The upper hose usually needs to be replaced more often because it handles all the really hot coolant coming right out of the head, and the lower hose just has to carry the nice cool coolant being returned to the block. Your situation is backwards. Hahaha

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'84 190D 2.2 5MT (Red/Palomino) Current car. Love it!
'85 190D 2.2 Auto *Cali* (Blue/Blue) *sold*
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I bought new hoses for my rad when I had the leak from the tranny cooler on my 85 300D that I wrote about. But after draining and checking out the installed hoses, I decided there was no need. Existing are also MB hoses, but I don't think original. May have been changed when engine was rebuilt. So I have spares on the shelf.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I wouldn't be surprised if the 38 year old hoses will outlast anything you can buy new. They must be made of plutonium or something!

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I have found that the original hoses REALLY last and remain near pristine... It has to be the low coolant temp and lack of solvents hitting it.

Fresh coolant changing regularity helps also.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I've seen Gates crack radiator endcaps because they were too rigid, FYI. A couple of VWs, and one Benz.

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1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

Those Mercedes hoses are good quality products. There were a few in my 220D, which was made in 1971, that were 42 years old when I replaced them. They were a bit cracked up on the outside though -- not nice like the hose you're showing us here.

All the clutch hydraulics lasted for over 40 years as well, but every component (master, slave, hose) failed right after the car turned 41.

I'll keep a look out for that. I'm putting a radiator from a 300SD into this car and I reinforced the necks using sheet aluminium and jb weld. I tried to find copper pipe to do it like Kent's kit but had no luck on finding that locally.

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Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.

^^^ I've said this in the past, but a good chance these plastic radiators fail is through the use a worm drive clamp instead of a spring/constant tension clamp.

Any advantage to "squeeze type" hose clamps?



.

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1983 123.133 California
- GreaseCar Veg System

Many plastics seem to continue to outgas for many years. Becoming more brittle as a result. Possibly they may also not tolerate the thermal changes constantly present in automotive cooling systems over the years as well.


Anyways there is little doubt that eventually they become at least somewhat more brittle then when new. The proper internal neck reinforcement is a good ideal. Especially on these vintage Mercedes. Plastic technology has probably improved over the years as well.