Hi all: In regards to the email that J.D. wrote, here is an excerpt from a web site I found that perhaps clears up this thing abut the proportioning valve. It probably explains it better than I can. By the way, no matter how I try, with my F, I cannot lock up my brakes but it comes to a stop in a mighty big hurry. Seems to me I am getting more use of the friction between the tires and the road than I would if the brakes were locked up and I am skidding out of control headed for who knows what. So guess which scenario I desire. **************************************************************************** ******** Proportioning Valve The proportioning valve reduces the pressure to the rear brakes. Regardless of what type of brakes a car has, the rear brakes require less force than the front brakes. The amount of brake force that can be applied to a wheel without locking it depends on the amount of weight on the wheel. More weight means more brake force can be applied. If you have ever slammed on your brakes, you know that an abrupt stop makes your car lean forward. The front gets lower and the back gets higher. This is because a lot of weight is transferred to the front of the car when you stop. Also, most cars have more weight over the front wheels to start with because that is where the engine is located. If equal braking force were applied at all four wheels during a stop, the rear wheels would lock up before the front wheels. The proportioning valve only lets a certain portion of the pressure through to the rear wheels so that the front wheels apply more braking force. If the proportioning valve were set to 70 percent and the brake pressure were 1,000 pounds per square inch (psi) for the front brakes, the rear brakes would get 700 psi. **************************************************************************** *********************** So, without a proportioning valve all brakes receive the same amount of braking pressure thus assuring that the rear brakes will lock up first and probably causing one to drive using the rear view mirror, backwards, that is. By the way, an old rule in racing is that if you need more brakes, install a smaller master cylinder ... but that's a whole new topic which I do not want to get into. So there you have it, I don't know what else I can say. I sleep well at night knowing I have the correct equipment on my car to stop it and protect my investment. Dan Reitz Northridge, CA 300F 1966 300 Convertible 1956 Dodge Custom Royal 1886 Benz In a message dated 10/13/2010 10:05:15 A.M. Pacific Daylight Time, retromobilia@xxxxxxxxxxx writes: Dan, In regards to the Prop-valve; You said the rears contact first and then the fronts? Is this not reversed, as in hard braking the rears will lock up as they are getting pressure proportionally to the front, in higher percentage....?! J D Jung Retromobilia.net ----- Original Message ----- From: dan300f@xxxxxxx To: MRS954@xxxxxxx, rpjasin@xxxxxxxxxxx, Chrysler300@xxxxxxxxxxxxxxx Sent: Tuesday, October 12, 2010 9:04:08 PM Subject: Re: [Chrysler300] Disc Brake Conversion for 300G Hi all again: I too wondered why I should have a proportioning valve on my '66 300. What woke me up was back about 20 years ago on my way to a 300 Club meet north of Seattle, I was crossing the bridge over the Columbia River in Portland. I was cruising along when all of a sudden I had no brakes but the emergency brake. I put it to good use and quickly got off the freeway at the next exit. Problem was that I had made an adjustment to the push rod in Grants Pass and it caused the fluid to back up into the master, taking fluid out of the lines to the brakes. You can fast forward with this story with a scenario where one of the brake lines fails for some reason. The result will be the same ... no brakes. If you have ever tried to put the binders on with an open cylinder, your foot will hit the floor. But, with a proportioning valve and a dual master cylinder, you have 2 separate circuits. One for the front wheels and one for the rears. With a proportioning valve, the rears contact first and then are followed by the fronts which do the majority of work to stop the vehicle. This helps to keep the car from swapping ends. Unless you have a major catastrophy wherein the master is wiped out, you have either the fronts to stop with or the rears. So, your odds of stopping and avoiding a collision are doubled. I am very happy I put a dual master cylinder and a proportioning valve on my '66 300 vert. and my F. Dan Reitz Northridge, CA In a message dated 10/12/2010 7:39:58 P.M. Pacific Daylight Time, _MRS954@xxxxxxxx (mailto:MRS954@xxxxxxx) writes: Bob, No, I didn't install a proportioning valve, other than the stock block. But I do know that I can lock up all 4 wheels (Bambi made me do it). I didn't see a need for a valve. All my former brake issues have been solved since I installed the AAJ set. After about 3 or 4 slow-downs or stops, the original brakes faded severely. After driving for some time, when I hit the hooks to stop for a traffic signal or stop sign, the car would veer off to one side or the other, never consistent. Each time I hit the brakes it was a new and exciting adventure. It got to the point where I hated to drive it, and I was ready to sell it. I took the car to my favorite shop where they turned the drums (again) and trued up the shoes to match the drums. Everything was new, from the master cylinder to the wheel cylinders, including hoses, stainless lines, everything. After the conversion, the car is fun to drive again. Mark -----Original Message----- From: Bob Jasinski <_rpjasin@xxxxxxxxxxxx (mailto:rpjasin@xxxxxxxxxxx) > To: _Chrysler300@xxxxxxxxxxxxxxxx (mailto:Chrysler300@xxxxxxxxxxxxxxx) Sent: Tue, Oct 12, 2010 12:11 pm Subject: RE: [Chrysler300] Disc Brake Conversion for 300G Mark, Did you install a proportioning valve, and if so what type and where did you nstall it? If you didn't, have you checked to see if your rear wheels and ront wheels lock up at the same time? AAJ suggests stopping on a gravel oad and adjusting the proportioning valve until the wheels lock up the ame. Dan Reitz writes that the '66 300 with disc brakes had a single pot aster and no proportioning valve from the factory, so are they really eeded? Bob J From: _Chrysler300@xxxxxxxxxxxxxxxx (mailto:Chrysler300@xxxxxxxxxxxxxxx) [mailto:_Chrysler300@xxxxxxxxxxxxxxxx (mailto:Chrysler300@xxxxxxxxxxxxxxx) ] On ehalf Of Mark Souders ent: Tuesday, October 12, 2010 7:32 AM o: _tc440@xxxxxxxxxxxx (mailto:tc440@xxxxxxxxxxx) ; _Chrysler300@xxxxxxxxxxxxxxxx (mailto:Chrysler300@xxxxxxxxxxxxxxx) c: _BEhrmann@xxxxxxxxxxxxxx (mailto:BEhrmann@xxxxxxxxxxxxx) ubject: Re: [Chrysler300] Disc Brake Conversion for 300G ick, used the basic kit from AAJ Brakes. After a few years of fighting brake ade and not knowing if or how my 300H would stop, I converted to front iscs. I did not change the master cylinder, I wanted to have the engine bay ook original. I did the conversion about 6 years ago, and I have no egrets. My brakes work fine now with no sudden surprises when applying the rakes. The AAJ basic kit comes with detailed instructions and a list of tems that must be purchased locally. AAJ does supply a complete kit but the reight charge to ship it across the country was more that a few tanks of as to drive to my local NAPA store. I lost a little sleep knowing the alipers were for a 76 Monte Carlo, but after my first drive with the new etup, I slept like a baby. Good luck with your project. Regards, ark Souders 00H ohrsville, PA -----Original Message----- rom: Rick Ehrmann <_tc440@xxxxxxxxxxxx (mailto:tc440@xxxxxxxxxxx) <mailto:tc440%40verizon.net> > o: _Chrysler300@xxxxxxxxxxxxxxxx (mailto:Chrysler300@xxxxxxxxxxxxxxx) <mailto:Chrysler300%40yahoogroups.com> c: Bruce Ehrmann <_BEhrmann@xxxxxxxxxxxxxx (mailto:BEhrmann@xxxxxxxxxxxxx) <mailto:BEhrmann%40stribling.com> ent: Mon, Oct 11, 2010 10:21 pm ubject: [Chrysler300] Disc Brake Conversion for 300G Hello friends - After a few years of sitting in a garage, my brother Bruce's s been revived. She's running fine, but after much brake work over the ears, 've decided to convert to front disc brakes and a dual master cylinder. I now me of you have already done this conversion. What has your experience been? hat parts or conversion kit did you use? Thanks for any insight on this you an fer. ick Ehrmann Non-text portions of this message have been removed] ------------------------------------ o send a message to this group, send an email to: _rysler300@xxxxxxxxxxxxxxxx (mailto:rysler300@xxxxxxxxxxxxxxx) <mailto:hrysler300%40yahoogroups.com> o unsubscribe from this group, send an email to _bob@xxxxxxxxxxxxxx (mailto:bob@xxxxxxxxxxxxx) mailto:bob%40simplexco.com> or to _http://autos.groups.yahoo.com/group/Chrysler300/join_ (http://autos.groups.yahoo.com/group/Chrysler300/join) and select the Leave oup" button or list server instructions, go to _ttp://www.chrysler300club.com/yahoolist/inst.htm_ (about:blank) or archives go to _ttp://www.forwardlook.net/300-archive/search.htm#querylangYahoo_ (about:blank) ! oups Links ndividual Email | Traditional _ttp://docs.yahoo.com/info/terms/_ (about:blank) [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: _hrysler300@xxxxxxxxxxxxxxxx (mailto:hrysler300@xxxxxxxxxxxxxxx) To unsubscribe from this group, send an email to _bob@xxxxxxxxxxxxxx (mailto:bob@xxxxxxxxxxxxx) or o to _http://autos.groups.yahoo.com/group/Chrysler300/join_ (http://autos.groups.yahoo.com/group/Chrysler300/join) and select the "Leave roup" button For list server instructions, go to _http://www.chrysler300club.com/yahoolist/inst.htm_ (http://www.chrysler300club.com/yahoolist/inst.htm) For archives go to _http://www.forwardlook.net/300-archive/search.htm#querylangYahoo_ (http://www.forwardlook.net/300-archive/search.htm#querylangYahoo) ! roups Links Individual Email | Traditional _http://docs.yahoo.com/info/terms/_ (http://docs.yahoo.com/info/terms/) [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: _Chrysler300@xxxxxxxxxxxxxxxx (mailto:Chrysler300@xxxxxxxxxxxxxxx) To unsubscribe from this group, send an email to _bob@xxxxxxxxxxxxxx (mailto:bob@xxxxxxxxxxxxx) or go to _http://autos.groups.yahoo.com/group/Chrysler300/join_ (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_ (http://www.chrysler300club.com/yahoolist/inst.htm) For archives go to _http://www.forwardlook.net/300-archive/search.htm#querylangYahoo_ (http://www.forwardlook.net/300-archive/search.htm#querylangYahoo) ! Groups Links [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! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/