As far as I am concerned dot 5 is not a contaminate. Sent from my iPhone 4 On Oct 14, 2010, at 9:06 PM, Herb <zephyr9900@xxxxxxxxxxx> wrote: > Up to you, I am not trying to get anyone to change back, just letting you > know the ramifications of changing over! Again just my two cents worth. > Front end replacement body parts are getting harder to find now days! Your > problem is you CAN NOT go back, unless you flush and replace every silicone > contaminated rubber and plastic component in your brake system. I was just > trying to help the other members before they made the same mistake you did, > the damage is done leave it! It is imperative that you do not commingle the > two fluids. You should mark your master cylinder as containing DOT 5 for > safety and future reference to future owners. > > > > > -------Original Message------- > > From: George McKovich > Date: 10/14/2010 9:26:44 PM > To: Intl 300 > Subject: Re: [Chrysler300] DOT Choice > > > All I had to hear was "I worked for the government" to convince me to stay > with dot5. > > George > > Sent from my iPhone 4 > > On Oct 14, 2010, at 8:07 PM, Herb <zephyr9900@xxxxxxxxxxx> wrote: > > > With all the talk about brakes and fluids, All I can say is your looking > for > > trouble with DOT 5. Once you change over you cant go back unless you > > replace EVERY rubber part in your brake system. Dot 4 does every thing DOT > > 5 does except contaminate the system with silicone, unless you live on the > > north or south pole, or are running a dedicated race car, DON'T DO IT. > > Extreme and I mean Extreme heat or cold conditions are all that I can > > justify the use of DOT 5. I worked for the government and converted > > hundreds of vehicles over to DOT 5, that experience is the reason I wont > do > > it to my cars. We kept consistently busy fixing DOT 5 related brake > > problems. The only reason they do change to DOT 5 is any vehicle can > > potentially go to any place in the world at any time, or that is the logic > > in the manual. I know, I know DOT 5 wont absorb moisture, that is correct > > but were does the moisture go??? O ya water is heaver than DOT 5, down to > > the bottom of the wheel cylinders and calipers to stay, and that is why > they > > start leaking from the corrosion on the sealing serfaces. If you > completely > > purge or bleed your brake system every 30,000 or 35,000 like your supposed > > to, you will never have corrosion problems with DOT 3 or 4 because the > > moisture that is absorbed by the DOT 3 is gone when you do a system bleed. > > > Problem is no one ever purges the system, out of sight out of mind until > you > > have brake problems, Same with Transmissions, no one changes fluid & > filter > > or thinks about it till a problem arises and by then it's tooooo late. O > Ya > > when you bleed DOT 5 were does the moisture go? OOps, it is still at the > > bottom of the wheel cylinders and calipers because it is not absorbed and > is > > heaver than DOT 5!! That said this is not an overnight problem with any > > brake fluid, most of our cars are forty five years old or older and the > > brake problems are just showing up. Actually I think the moisture that is > > absorbed, is really a good thing if you service your system on a regular > > basis. That is why I invested in a power bleeder, about every five or six > > years I purge the systems on my cars and never have any problems other > than > > replacing shoes or pads. Here is an article that is good information. This > > is just my $00.02 worth from experience, and I know everyone has a > > conflicting opinion, this is just mine. > > > > > > Battle of the DOTs > > DOT 3-4 Verses DOT 5. Which brake fluid should I use? > > "With regards to the DOT 3-4 verses DOT 5 brake fluid controversy, here is > > an article sent to me by Mr. Steve Wall. It is one of the most > professional > > treatments I have seen on the subject". > > [I had to condense this article from 6 pages to 1 due to space limitations > > > Brake Fluid Facts > > By Steve Wall > > As a former materials engineering supervisor at a major automotive brake > > system supplier, I feel both qualified and obligated to inject some > material > > science facts into the murky debate about DOT 5 verses DOT 3-4 brake > fluids. > > The important technical issues governing the use of a particular > > specification brake fluid are as follows: > > 1. Fluid compatibility with the brake system rubber, plastic and metal > > components. > > 2. Water absorption and corrosion. > > 3. Fluid boiling point and other physical characteristics. > > 4. Brake system contamination and sludging. > > Additionally, some technical comments will be made about the new brake > fluid > > formulations appearing on the scene. > > First of all, it's important to understand the chemical nature of brake > > fluid. DOT 3 brake fluids are mixtures of glycols and glycol ethers. DOT 4 > > contains borate esters in addition to what is contained in DOT 3. These > > brake fluids are somewhat similar to automotive anti-freeze (ethylene > > glycol) and are not, as Dr. Curve implies, a petroleum fluid. DOT 5 is > > silicone chemistry. > > Fluid Compatibility > > Brake system materials must be compatible with the system fluid. > > Compatibility is determined by chemistry, and no amount of advertising, > > wishful thinking or rationalizing can change the science of chemical > > compatibility. Both DOT 3-4 and DOT 5 fluids are compatible with most > brake > > system materials except in the case some silicone rubber external > components > > such as caliper piston boots, which are attacked by silicon fluids and > > greases. > > Water absorption and corrosion > > The big bugaboo with DOT 3-4 fluids always cited by silicone fluid > advocates > > is water absorption. DOT 3-4 glycol based fluids, just like ethylene > glycol > > antifreezes, are readily miscible with water. Long term brake system water > > content tends to reach a maximum of about 3%, which is readily handled by > > the corrosion inhibitors in the brake fluid formulation. Since the > > inhibitors are gradually depleted as they do their job, glycol brake fluid > > > just like anti-freeze, needs to be changed periodically. Follow BMW's > > recommendations. DOT 5 fluids, not being water miscible, must rely on the > > silicone (with some corrosion inhibitors) as a barrier film to control > > corrosion. Water is not absorbed by silicone as in the case of DOT 3-4 > > fluids, and will remain as a separate globule sinking to the lowest point > in > > the brake system, since it is more dense. > > Fluid boiling point > > DOT 4 glycol based fluid has a higher boiling point (446F) than DOT 3 > (401F) > > and both fluids will exhibit a reduced boiling point as water content > > increases. DOT 5 in its pure state offers a higher boiling point (500F) > > however if water got into the system, and a big globule found its way into > a > > caliper, the water would start to boil at 212F causing a vapor lock > > condition [possible brake failure -Ed.]. By contrast, DOT 3 fluid with 3% > > water content would still exhibit a boiling point of 300F. Silicone fluids > > also exhibit a 3 times greater propensity to dissolve air and other gasses > > which can lead to a "spongy pedal" and reduced braking at high altitudes. > > DOT 3 and DOT 4 fluids are mutually compatible, the major disadvantage of > > such a mix being a lowered boiling point. In an emergency, it'll do. > > Silicone fluid will not mix, but will float on top. From a lubricity > > standpoint, neither fluids are outstanding, though silicones will exhibit > a > > more stable viscosity index in extreme temperatures, which is why the US > > Army likes silicone fluids. Since few of us ride at temperatures very much > > below freezing, let alone at 40 below zero, silicone's low temperature > > advantage won't be apparent. Neither fluids will reduce stopping distances > > > With the advent of ABS systems, the limitations of existing brake fluids > > have been recognized and the brake fluid manufacturers have been working > on > > formulations with enhanced properties. However, the chosen direction has > not > > been silicone. The only major user of silicone is the US Army. It has > > recently asked the SAE about a procedure for converting from silicon back > to > > DOT 3-4. If they ever decide to switch, silicone brake fluid will go the > way > > of leaded gas. > > Brake system contamination > > The single most common brake system failure caused by a contaminant is > > swelling of the rubber components (piston seals etc.) due to the > > introduction of petroleum based products (motor oil, power steering fluid, > > mineral oil etc.) A small amount is enough to do major damage. Flushing > with > > mineral spirits is enough to cause a complete system failure in a short > time > > I suspect this is what has happened when some BMW owners changed to DOT 5 > > (and then assumed that silicone caused the problem). Flushing with alcohol > > also causes problems. BMW brake systems should be flushed only with DOT 3 > or > > 4. > > If silicone is introduced into an older brake system, the silicone will > > latch unto the sludge generated by gradual component deterioration and > > create a gelatin like goop which will attract more crud and eventually > plug > > up metering orifices or cause pistons to stick. If you have already > changed > > to DOT 5, don't compound your initial mistake and change back. Silicone is > > very tenacious stuff and you will never get it all out of your system. > Just > > change the fluid regularly. For those who race using silicone fluid, I > > recommend that you crack the bleed screws before each racing session to > > insure that there is no water in the calipers. > > New developments > > Since DOT 4 fluids were developed, it was recognized that borate ester > based > > fluids offered the potential for boiling points beyond the 446F > requirement, > > thus came the Super DOT 4 fluids - some covered by the DOT 5.1 designation > - > > which exhibit a minimum dry boiling point of 500F (same as silicone, but > > different chemistry). > > Additionally, a new fluid type based on silicon ester chemistry (not the > > same as silicon) has been developed that exhibits a minimum dry boiling > > point of 590F. It is miscible with DOT 3-4 fluids but has yet to see > > commercial usage. > > > > > > > > > > Herb > > > > 1956 Plymouth Belvedere 361 4-Sale > > 1959 Coronet 326 Poly > > 1961 Belvedere Custom Suburban 318 Poly > > 1962 Dodge Dart 225 Slant Six 4-Sale > > 1963 Fury 2D/HT 6.1L > > 1963 Sport Fury Convertible 361 > > 1970 Chrysler 300 Hurst 440 > > 1999 Durango SLT 5.9L > > 2008 SRT-8 Magnum 6.1L > > St. Louis, MO. > > > > [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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