[R129 SL] Fire Extinguishers!

[Peter Shelton]

BerichtHi Jan,
The foam extinguisher is a great idea and can generally be used on both electrical and fuel fires (Do not use wet foam types on vehicles).  I have overseen a contract in a military aircraft facility with 6 foam extinguishers in a large hangar.  The foam towers were about 3.5 m high, and each tower was equipped with auto directional 4 inch jets that seeked out the hottest source of the fire and sprayed foam.  Note that foam expands between about 7% and 2,000 % depending upon the type of foam and the concentration of foam reactant. 

For information, below is an extract from some of my notes on dry powder extinguishers (I use this with insurance companies!)  Most Dry powder types contain Ammonium phosphate (quite corrosive) but there are other chemical products used.  

"Multi-purpose (ABC-rated) chemical extinguishers (except Halon) leave a residue that can harm sensitive equipment, such as computers, electronic equipment and internal combustion engines.   Because of this, carbon dioxide or Halon extinguishers are preferred in these instances because they leave very little residue.  ABC dry powder residue is mildly corrosive to many metals."

This statement is another 'nail' in why we should not have dry powder extinguishers in our cars.  They do put out the fire though, and insurance does not usually cover petrol type fires!  Check your policies. 

Most foam types can only be used on A and B type fires (General and liquids),but they are not too good on gaseous vapour fires. Choose carefully!  Halon is the best but it is banned in most countries.  If you can source the extinguishers, Inergen, FM200, and even the old CO2 is very good.

Note that most commercial vehicles are fitted with dry powder as they are good on AB and C type fires.  The reason they are used (and corrosive) is that they are cheap! 

Oh yes, If you have a fire under the hood, do NOT open the hood (air and petrol go whoosh!).  Release the hood lever and pour the extinguisher contents between the gap!

Hope you do not all have a fire in any of your vehicles!. 

Regards, Peter S. 

 
  From: Jan Kuylaars 
  To: 'Peter Shelton' ; 'SL Mailing List' 
  Sent: Monday, July 16, 2007 8:24 AM
  Subject: RE: [R129 SL] Another air conditioning question


  Peter;
  Yeah, it should be better to buy a foam fire Extinguisher. When you need it, it is worth the extra amount of money for saving the rest of the car.
  But I also have at home and in my car a powder one.
  I shall replace the one in the car and give the powder to someone else for free.

  Last month I let replaced the clutch with all parts from my Mazda 929. Now my 500 SL is standing still in my garage I was happy to have this car as spare.
  Using it this weekend my clutch pedal stays on the floor an I could not shift anymore. Let it ride in second gear I was driving to my mechanic hoping I did not have to stop for a traffic light. Then I take my foot under the pedal and pull it back upwards. After that I could use the clutch again and after shifting some times I drove back at home. When I was home I checked the oil level from the clutch pedal. It was between full and minus, it was not clear anymore but grey.
  I took out the amount of grey oil and cleaned the reservoir with a cloth. Then I filled it with new brake oil. Testing it results in good working.
  So I hope this will save the problem. Otherwise I must replace the cups in the pedal cylinder.

  The sun was shining and we have a temperature of more than 30 degrees Celsius. So I thought I take my Yamaha 1330 Venture bike and use it this weekend.
  The first thing I thought was: it will not start. And yes, I was right. Starting it with help from my Mazda battery let it rues normal.
  So I drove some miles , but takes starting cable with me for sure. And that was necessary. After shut down the bike it would not start again.
  Help from a nice lady solve the problem for a while and I drove home. Having the battery one night on full charge it started this morning without problems.
  But after starting several times I measure the voltage on the battery and while the start motor hacked, the voltage dropped under 6 volts.
  So tomorrow I am going to buy a new battery. Then my back tire what has been replaced last winter for new, had only 1.5 bar left. 
  Visiting 3 gestations before I find a air pump what I could use on my back tire .

  After this I have checked all fluids and all pressure's on all my vehicles and asking myself what will be the next failure.

  But I droved some miles today with nice sun .

  Greetings from Jan.

    -----Oorspronkelijk bericht-----
    Van: r129list-bounces at mbcoupes.com [mailto:r129list-bounces at mbcoupes.com] Namens Peter Shelton
    Verzonden: zaterdag 14 juli 2007 1:17
    Aan: SL Mailing List
    Onderwerp: Re: [R129 SL] Another air conditioning question


    Hi Jan,  

    Not good about your gearbox. I have spares for 201's and 123's but not for a 129.  I bought a brand new 129 left headlight off "trademe" (NZ equivalent of EBay) last week. Bought as an 'in case' spare.  genuine part - $125 euros.  Amazing what people have in their sheds!

    Jan, after 'frying' your gearbox, maybe you could call yourself the "Frying Dutchman" rather than the "Flying Dutchman"!  It nearly sounds the same?. 

    One of our newer members in our NZ Mercedes Benz Club recently bought a 1974 350SL.  The fuel line leaked and the engine caught fire!   Did a bit of damage but it was extinguished with a Fire Extinguisher.  It was a dry powder (mica) type - what a mess it left and it is corrosive!  Also no insurance for this in NZ and he is an insurance agent/ investigator.  I have nick named his car "The Barbeque"  for obvious reasons.  I suggest we all check our fuel lines frequently as perishing fuel lines can be fatal.  

    Jan, your description of the aircon is very good.  It is important to measure the on/off coil temperatures as this gives an immediate indication of where the problem may lie.  Bubbling in the accumulator sight glass is also an indicator.  

    Great sunny day in Eco City (Manawatu NZ).  The day started off at minimum 2 and it is about 15 degrees now.  It is hot from the sun, as the ozone layer over our country is depleting fast, and the UV filtering effect of Ozone is nearly non existent.  Well, time for a ride in the 500SL, have to make the most of the sunny days. 

    Regards, Peter S.
      ----- Original Message ----- 
      From: Jan Kuylaars 
      To: 'SL Mailing List' 
      Sent: Friday, July 13, 2007 10:30 AM
      Subject: Re: [R129 SL] Another air conditioning question


      George.

      I am not a expert in AC, but basic working is that the compressor compresses the gas to fluid and the fluid is giving of the heat that is produced by compressing.
      The front radiator is for cooling the heated fluid by passing air while driving, or by air stream with the electric fans, during standing still. The heated gas is pumped to the receiver drier to take out the moister. After the drier there is a pressure control switch for shut down the AC if the pressure is to low and a other for running the electric fans if the pressure is to high.

      If you system is not completely filled, you can see air bubbles in the glass from the drier when the compressor is running. 
      When you see no bubbles there is to less or no refrigerant.You can check on the compressor. There should be a different in temperature in the inlet and outlet
      After the compressor stops , and there is a clear vision in the glass, there is to much refrigerant in the system.
      If the amount of refrigerant is perfect, the refrigerant should foam and then stay clear after the compressor stops.

      From the drier the fluid runs to the evaporator inside the car , where the fluid can expand to gas again, and for this expand the gas needs heat.
      The evaporator takes the heat from the room and the room becomes cool. 

      From the evaporator the gas is flowing back to the compressors low pressure side, where the gas is compressed again to fluid and the process starts again.

      So as long as your car is driving and the radiator will be cooled there is no problem.
      When your car is standing still and the engine temperature is climbing the problems starts;

      There are in mine opinion two possibilities, I am not for sure , but I am are trying to think with you :
      First there could be  a failure in the basic operation, and the second one is electronic problem from the regulation of he AC.

      Lets start by the first: if your car is standing still and your electric fans are not working, the fluid is not been cooled and the heated fluid results in higher pressure .
      Also there is a higher temperature in your evaporator. There is expanding from the gas but it don't needs a lot of heat for this because the temperature already is high. The result could be that the emission of heat out of your car to the evaporator is gone. So no cooling.
      This could be resulting in a spiral. After the pressure comes too high the system shut down or the refrigerant will come out the high pressure security valve.
      Result to low refrigerant and not proper working of the AC.

      Possible failure could be the fans, the fan control, the pressure switch or the expansion valve which are not good operating with higher pressure or heat.

      Then there is a possibility for electronic failure , like the Italian college told; The measure of inside temperature and outside temperature in combination with the temperature from the engine. He told us to fix this problem with a resistor placed in series with the engine temperature sensor. Read the earlier messages.

      Also there can be a failure in the circuit itself.
      When you wish I can send you the electronic circuit diagrams and the diagnose procedure.

      Greetings from the standing still Dutchmen with damaged gearbox. 

      I discovered on the bill from my garage that beside replacement from the starter and the steering house, they replaced the rubber pipe from the gearbox oil cooler because it should leak a bit. After that I only drove 40 miles before my gearbox looses oil with pump noise and burned oil on the exhaust as result.
      I must check if the rubber pipe is come loose, and maybe they are the reason of no just oil level or other damage.
      But then I have a problem if they are willing to confess and pay for the damage.

      Jan.










        -----Oorspronkelijk bericht-----
        Van: r129list-bounces at mbcoupes.com [mailto:r129list-bounces at mbcoupes.com] Namens George Jenner
        Verzonden: donderdag 12 juli 2007 15:59
        Aan: SL Mailing List
        Onderwerp: [R129 SL] Another air conditioning question


        I have been experiencing a perplexing problem with my 1996 SL500 air conditioning system.  I have the means to check the pressure on the system and have noticed that when I first start the car the air conditioned runs normally cold.  As I drive and the car heats up the system runs normally, but if I turn off the engine (to gas up) and the out door temp. is hot (in the high 90s) when I restart the car the air conditioner is no longer running cold.  This has led me to check the system pressure at various engine temperature stages and the pressure is in the normal 40 - 50 range when the system is cooling normally but jumps to 100 + when the engine is hot and the system no longer is  cooling.  I do not think I am loosing coolant but need help to locate the problem.

        Has anyone any idea of what may be causing this problem?

        Thanks, George


--------------------------------------------------------------------------


      The MB Coupes Website!
      R129 SL Mailing List 


--------------------------------------------------------------------------


      No virus found in this incoming message.
      Checked by AVG Free Edition. 
      Version: 7.5.476 / Virus Database: 269.10.5/899 - Release Date: 13/07/2007 3:41 p.m.



------------------------------------------------------------------------------


  No virus found in this incoming message.
  Checked by AVG Free Edition. 
  Version: 7.5.476 / Virus Database: 269.10.6/900 - Release Date: 14/07/2007 3:36 p.m.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.pairlist.net/pipermail/r129list/attachments/20070716/6523bec2/attachment.htm>