Hi there, I always research the forum before doing work on my cars. Bad memory requires refresh etc.

I already did archive searches and also looked at DIY links.

I know how to drain the radiator but to refill this radiator which has no 'radiator cap', do I rely on the plastic remote reservoir tank to refill or do I have to remove a radiator hose in order to fill the radiator and then top off via the reservoir??

Thanks.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Fill via the resevoir

I usually take the upper hose off of the engine, swivel it up and use it as a funnel. Uncap the reservoir so air can escape, and fill via the hose. You should see the reservoir fill up as the level rises, you can reconnect the upper hose at any time and fill the reservoir, I just prefer the alternate method I just described. More importantly, just make sure that the system is bled properly to remove air bubbles.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

There is a screw on the top of your thermostat housing, uscrew that to bleed the air out while filling.

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Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

unkl300d, follow tbomachines' method for filling the radiator because that is the simplest way to avoid having air trapped inside. Best to remove the thermostat housing and thermostat and refill the block to just below the thermostat location to avoid having air trapped in the block. After the thermostat housing and upper radiator hose are reinstalled run the engine up to operating temperature and let it cool down. Add coolant as required to the expansion tank.

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Fred Hoelzle

OK thank you all for the insights.

I'll go ahead and remove the hose etc. and look for the 'bleed screw' also.
It was just that the reservoir hose seemed small diameter for an intuitive radiator filling purpose...

I'll take the opportunity to perhaps fit in an aluminum fitting to add strength to the plastic neck.
Yup, my replacement Behr radiator years ago still came with a plastic neck !

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Task completed !

Although I have a Behr radiator, funny thing is that I could not find the typical rad. plug under the driver side of rad. (or pass. side), where it typically is found.
So I just undid the pass side lower rad. hose.

My thermostat housing did not have a bleed screw.
I just let the car idle with reservoir cap off to give it a chance to get the air out.
Good for another 3 yrs.

THX.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Hmm, do you have one of the plastic thermostat housings?

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

unkl300d, typically the drain valve on a Behr radiator is on the passenger side, and has a male discharge piece that accepts tygon tubing so you can drain the coolant into a container.

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Fred Hoelzle

tbomachines, yes black plastic one.

Ferdman, on the bottom of the passenger side there was something that more resembled a plastic plug BUT did not have a typical flat head screw driver female slot. It had two deep slots like a small electrical plug socket.
It did not budge so I did not force it.
No male discharge piece that I saw unless it is somewhere other than at the bottom surface.
I don't doubt you. Behr may have variants.

Thanks !

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

unkl300d, it would be best to replace the plastic thermostat housing with a metal one (available at your local MB dealer).

__________________
Fred Hoelzle

X2, I'm not sure I'd want to pay dealer prices though. If you're a junkyard type of guy, grab one off of a later M103 they're pretty easy to find. There are usually members parting out M103s in the parts classifieds section of the forum too, you could get one from them. The reason I asked (and Ferdman also recommends replacement) is because the plastic has a bad reputation for getting brittle and cracking after many heating/cooling cycles. The aluminum ones with the bleeder screw are much more durable.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

Ferdman and tbomachines,

Yes ! Also I agree that the junk yard is the way to go.

I just fixed a hole in the 300Se muffler today.

Need to replace the valve cover gasket also. Another thing that gets brittle with time !

One thing at a time !

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD