Herb, We've been down this road before, but for the sake of balance I would like to respond to the points you've made based on my experience: <Again if you do proper maintenance you WILL NOT have a problem!!> In a perfect world that all I had to do was schedule brake bleeding sessions every two years, that would be the case, but that is not reality in my life. I own a number of cars, all requiring maintenance of some type at any one point in time. Bleeding brakes is NOT a simple one man job, it is a lot of work, even with a lift as I have. The longer I can do without the need, the better. Some years I only put 800 to 1000 miles on my 300G. That would require brake bleeding as often as an oil change. Also, more frequent brake fluid changes means more possibility of SPILLING DOT3/4 brake fluid on painted surfaces, causing damage. <By the way the same moisture that is in DOT 3-4 is in DOT 5 it just sinks to the lowest point and sits there as opposed to DOT 3-4 that holds it in suspension and is gone when you bleed your brakes. Not sitting at the low spots unable to be bleed out like as with DOT 5> Sorry, but this is not true. DOT 5 does NOT absorb the same amount of moisture in the system as does DOT3/4, as they are hygroscopic (attract moisture) DOT 5 is not hygroscopic. Over many years, moisture can accumulate in a DOT 5 system, but it is at a much slower rate. It does form in the lowest point, but that is flushed when the brakes are bled, just as it would with DOT 3/4. The difference though, is that you can wait MUCH longer to bleed the brakes. I do mine about every 8 years. <Is there anything wrong with DOT 5, NO, other than the silicone impregnates all rubber parts and creates a mess if you want to switch back> I have not seen any evidence of permanent contamination of brake parts caused by silicon fluid. < Today's DOT 4 has just short of the same boiling quality's as DOT 5> True, but that is when it is fresh. The boiling point begins to drop once it is installed due to the hygroscopic nature of DOT 3/4. The silicon fluid boiling point remains much more constant through its life. A good alternative to silicon fluid is Castrol DOT 4 LMA (low moisture activity) fluid. It has a high boiling point, BUT it still melts paint. In collector cars like ours, that is a MAJOR drawback. Bob J From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Herb Sent: Sunday, February 06, 2011 6:43 PM To: Chrysler 300 List Subject: Re: [Chrysler300] Dot 3 / Dot 5 Again if you do proper maintenance you WILL NOT have a problem!! By the way the same moisture that is in DOT 3-4 is in DOT 5 it just sinks to the lowest point and sits there as opposed to DOT 3-4 that holds it in suspension and is gone when you bleed your brakes. Not sitting at the low spots unable to be bleed out like as with DOT 5. Another post talked of the boiling point of DOT 3-4 over DOT 5. Todays DOT 4 has just short of the same boiling quality's as DOT 5. To address the boiling, unless he is racing on a track his problem is unrelated to fluid!! If your brakes are getting so hot that your boiling fluid you need to find a real mechanic to do your brakes because quite frankly whom ever did them knows not what they are doing. Bottom line, the perceived benefits from DOT 5 are just not there in a street car in the lower 48 or lower 55 states, if your a fan of mr obama. I have many years of experience with both fluids, and have never been convinced that the added expense reaped any justifiable benefit. Is there any thing wrong with DOT 5, NO, other than the silicone impregnates all rubber parts and creates a mess if you want to switch back. Is there any thing wrong with DOT 3 or 4, NO, if you change it like your supposed to during normal preventative maintenance! Brakes are like transmissions out of sight out of mind until there is a problem. Then we try to find something to blame, other than our selves, and what is the easiest thing? Fluid! That is why there is such an after market for wonder fluids!! All stemmed from personal denial. Why do you have sludge in your engine? You did not change your fluid! Why do you have a burned up transmission? You did not change your fluid! Why do you have rusted brake components & lines? You did not change your fluid! SO, Pay now and change your fluids or Pay more latter! -------Original Message------- From: mgoodknight@xxxxxxxx <mailto:mgoodknight%40juno.com> Date: 2/4/2011 7:14:40 PM To: zephyr9900@xxxxxxxxxxx <mailto:zephyr9900%40hotmail.com> Cc: 2HsandaHeritage@xxxxxxxxxxx <mailto:2HsandaHeritage%40comcast.net> ; chrysler300@xxxxxxxxxxxxxxx <mailto:chrysler300%40yahoogroups.com> Subject: Re: [Chrysler300] Dot 3 / Dot 5 If you haven't lived in Florida or other damp coastal areas it might be difficult to appreciate the deficiencies of Dot 3 for use in "occasionally used" vehicles. ---------------Marshall ---------- Original Message ---------- From: Herb <zephyr9900@xxxxxxxxxxx <mailto:zephyr9900%40hotmail.com> > To: <2HsandaHeritage@xxxxxxxxxxx <mailto:2HsandaHeritage%40comcast.net> >, "Chrysler 300 List" <chrysler300@xxxxxxxxxxxxxxx <mailto:chrysler300%40yahoogroups.com> > Subject: Re: [Chrysler300] Dot 3 / Dot 5 Date: Fri, 4 Feb 2011 15:47:20 -0600 DOT 5, WHY????? Please send your extra unneeded money to me, I sure can use it on my 300H!! Use DOT 4 and save your time and money, there is NO advantage to DOT 5 in Fair Oaks, CA! Now if you lived in Fair Banks, Alaska , maybe a slim chance. Just change the fluid every 30,000 miles with DOT4 as your supposed to, and you will never have a fluid problem. -------Original Message------- From: 2HsandaHeritage@xxxxxxxxxxx <mailto:2HsandaHeritage%40comcast.net> Date: 2/4/2011 10:51:28 AM To: Chrysler 300 Club International Subject: [Chrysler300] Dot 3 / Dot 5 Hi Group, The rear brake assemblies on my new 300 Sport are severely corroded due to leaking wheel cylinders and long storage. I have decided to switch from Dot 3 to Dot 5 brake fluid. My procedure will be to remove all wheel cylinders and hoses, remove , disassemble and clean the master cylinder, blow out the steel tubing with compressed air and flush the tubing with a solvent. I will then install new wheel cylinders and hoses, add Dot 5 and bleed the system. Any comments or suggestions on this procedure? What should I use to flush the steel tubing? Thank in advance, Doug Warrener Fair Oaks, CA 300H 300 Sport Conv. [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! 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