Author Topic: Unknown Firewall Pipes  (Read 1676 times)

edwardburak@erols.com

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Unknown Firewall Pipes
« on: September 15, 2021, 12:00:32 »
1969 280sl automatic USA Version

What is the purpose of these pipes on each side of the firewall?

Are they heater pipes? vent pipes?

I have not started myt engine yet, do I need to plumb these pipes to somewhere?
thanks

Harry

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Re: Unknown Firewall Pipes
« Reply #1 on: September 15, 2021, 14:09:58 »
Those appear to be the (rain/wash) water drain pipes for the fresh air intake.  They normally have rubber bulb on the end, with a slit in the bottom.
Harry Bailey
Knoxville, TN
1966 230SL
Automatic

edwardburak@erols.com

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Re: Unknown Firewall Pipes
« Reply #2 on: September 15, 2021, 16:59:15 »
Thank you, do you know if those bulbs are still available? Perhaps part number? Thanks

GM

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Re: Unknown Firewall Pipes
« Reply #3 on: September 15, 2021, 18:30:21 »
110-831-01-32
Gary
1971 280SL - Sold
(98 from the end of production)
DB180 Silver Gray Metallic
Black MB Tex

Benz Dr.

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Re: Unknown Firewall Pipes
« Reply #4 on: September 15, 2021, 18:52:44 »
Rubber bulb is only used on the left side.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

mrfatboy

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Re: Unknown Firewall Pipes
« Reply #5 on: September 15, 2021, 19:21:29 »
The original size of the tube is 15mm. You can buy the 20mm tube size and do a slight modification to fit the larger tube opening. Much cheaper if money is an issue.

https://www.authenticclassics.com/SearchResults.asp?Search=Water+drain+valve
1969 280sl (Aug 1968 build)
Signal Red
4 Speed

Pawel66

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Re: Unknown Firewall Pipes
« Reply #6 on: September 15, 2021, 19:27:30 »
They are horrifyingly expensive at MB. Try SLS or Niemoeller or, best one of the US suppliers.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

Cees Klumper

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Re: Unknown Firewall Pipes
« Reply #7 on: September 15, 2021, 22:51:40 »
Is the bulb really necessary, i.e. does water and / or dirt travel upwards into the tubes? Or is the bulb to keep noise out?
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

mrfatboy

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Re: Unknown Firewall Pipes
« Reply #8 on: September 15, 2021, 23:17:15 »
Well..... if you don’t have it JonB will deduct 1/4 point off your car the next time he sees you 🤣

But seriously, mine was missing for 20 years because I never knew I was supposed to have one until a fellow member pointed it out.

On a side note, my father’s 2007 jag has a very similar bulb. All the excess water comes out including the AC condensation. The bulbs are notorious for sealing up and sticking together. The water backs up into the fan motor and burns it out while dumping the excess water under the dash on the passengers feet.

The bulb on the jag is behind the engine and not easily accessible. Some people have pulled the transmission at great expense to access it.

After years of trying to find a non expensive/invasive solution I found a post by a guy that stuck a razor blade on a coat hanger and routed it past  the tranny and behind the engine (car on lift) and felt for the bulb and cut it😳. No more water back up. Spiders, mice, dirt maybe but no water 🤣
« Last Edit: September 15, 2021, 23:53:24 by mrfatboy »
1969 280sl (Aug 1968 build)
Signal Red
4 Speed

edwardburak@erols.com

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Re: Unknown Firewall Pipes
« Reply #9 on: September 15, 2021, 23:50:21 »
thanks for your help

66andBlue

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Re: Unknown Firewall Pipes
« Reply #10 on: September 16, 2021, 03:43:21 »
Is the bulb really necessary, i.e. does water and / or dirt travel upwards into the tubes? Or is the bulb to keep noise out?
Cees,
take your pick among the functions that were suggested here and why there isn't one on the passenger side pipe:
https://www.sl113.org/forums/index.php?topic=6092.
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)