RE: [Chrysler300] 300C Brakes
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RE: [Chrysler300] 300C Brakes

Recalling that there is a small device in the outlet of the MC that is there to hold a small amount of pressure on the lines and wheel cylinders with the brake pedal released.  This device is referred to as a check valve and may or may not be more sophisticated than a small orifice.  Its purpose is to hold enough positive pressure on the wheel cylinders to minimize the inhaling of cool, moist air into the wheel cylinders when the fluid contracts and expands with temperature.  Whatever the device is, if it is plugged or malfunctioning it could hold more pressure on the system than is desired.  I don’t know any way of checking this other than disconnect the tubing at the outlet of the MC, connect it to a bleeder bottle and punch the pedal a couple of times to make sure the outlet is clear.


Those of us with J’s and ram K’s know that this “check valve” device must be removed from the firewall-mounted MC to prevent pressure buildup at the remote booster and resultant brake dragggg.


Finally, it is the job of the brake shoe return springs to force the brake fluid back into the MC reservoir.  Proper springs, properly installed and sliding surfaces at the backing plates very lightly lubed with proper lube help assure this function.


Keep calm and 300 on.


Rich Barber

Brentwood, CA



From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Oddvin Skråmestø oddvin@xxxxxxxxxxxxxxxxxxxx [Chrysler300]
Sent: Thursday, October 01, 2015 10:14 AM
To: Anna F Noia <sa-noia@xxxxxxxxxxx>; Lynn <lynnd@xxxxxxxxxxxxxxxx>; Ray Jones <1970hurst@xxxxxxxxx>
Cc: Listsaver 300 Club <Chrysler300@xxxxxxxxxxxxxxx>
Subject: Re: [Chrysler300] 300C Brakes



I was thinking the same as you Stephen.

If the MC piston and seal doesn’t return enough, it will cover the little hole for return of brakefluid from the lines.

Both front brakes are dragging, probably the rear too. I did not lift the rear end checking. The right front was dragging more than the left front, most likely because of incorrect adjustment.

I felt the car was pulling to the right, and the right drum became warmer than the left. Thats how i noticed this.

The short brake hose from the MC is not there any more. I gave the new brakeline out of the MC, two loops, like modern cars. This was done 25 years ago.

Collapsing brake hose. Yes I have experienced this in 2007. Than the right front brake hose was collapsed all the way. What I ride! Each time braking, the car pulled to the left. Release the pedal it pulled to the right.

I was driving 2000km this way. Never more.

If the brake hose this time is collapsed, I would have had trouble bleeding the system. But the fluid came out as normal.

I will check the clearance between the input rod and MC tomorrow, then adjust the brakes again.


Thanks for input.




Sent: Thursday, October 01, 2015 3:54 PM

Subject: Re: [Chrysler300] 300C Brakes



Check the MC input rod from the peddle, it needs to release the master completely plus about a 1/16 of inch. If the rod doesn't release completely, the pressure will remain at the cylinders and cause the brakes to drag. I my case it was cumulative, several applications of the brakes caused more pressure to them eventually locking them up. Just a suggestion.

Best Regards,
Stephen A. Noia
1-408-210-4736 cell



On Wednesday, September 30, 2015 2:54 PM, "'Lynn' lynnd@xxxxxxxxxxxxxxxx [Chrysler300]" <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote:



You might also check the short hose from the master cylinder also.  I had one of those collapse internally on my 57 Desoto and caused the same symptoms. 


Sent: Wednesday, September 30, 2015 2:06 PM

Subject: Re: [Chrysler300] 300C Brakes



Which brakes are dragging?

You might want to replace the rubber hoses from the front brakes to the frame.

They can deteriorate inside and end up with a flap of rubber hanging down inside the hose and acting like a valve.

Pressure to the brake pushes it out of the way and with no pressure, the flap falls down into the hose and prevents the fluid from returning to the MC.



On Wed, Sep 30, 2015 at 2:06 PM, Oddvin Skråmestø oddvin@xxxxxxxxxxxxxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote:



I have replaced the mastercylinder, and serviced the wheelcylinders on my 300C. And I have adjusted the brakes according to the sevice manual.

It seems like there are still pressure present in the system after the brakes are released. The brakes are dragging.

I forgot to check the free play between the push rod, and mastercylinder. I hope the pedal free play adjustment will do the trick. Otherwise I’m out of good ideas.

I will try this on friday night, and I’m hoping to use the car on saturday at the end of season cruisin’.

Any ideas?



300C in Norway


Ray Jones. Y'all come on down an see us. Ya hear?



Posted by: "Rich Barber" <c300@xxxxxxx>

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