Brake Proportioning Valve

[Wayaroundit2]

Converted my front brakes to the DCM disk conversion kit. I needed a brake Proportioning Valve to evenly distribute the fluid because the disks lock up.  My question is where does it go there is an In & Out does the Proportioning Valve go on the out of the master cylinder or do I need one for each disk brake ? One thing I'm not is a Proportioning Valve wizard any help?

[knuckleharley]

I am surprised one didn't come with the kit

[knuckleharley]

47 minutes ago, Wayaroundit2 said:

Converted my front brakes to the DCM disk conversion kit. I needed a brake Proportioning Valve to evenly distribute the fluid because the disks lock up.  My question is where does it go there is an In & Out does the Proportioning Valve go on the out of the master cylinder or do I need one for each disk brake ? One thing I'm not is a Proportioning Valve wizard any help?

I am not sure why I wasn't able to finish my first post to you,but I wasn't.

 

Anyhow,one should have came with your conversion kit. Contact the seller is see if they just forgot to add it to the kit.

[Wayaroundit2]

I did contact them an it's a separate part. He just wrote back an said it also needs in each front line a  2 PSI Residual Valve it makes sense because the rear take 8 to 10 lb an disk take 3 to 5 . I was told the proportion valve is to direct most pressure to rear drums an residual holds a 2 psi for the front an will hold back pressure for the calapers.  I will try a 2psi residual on each disk line . Thanks for reply all locked up here !

[Doug&Deb]

Do you still have the original master cylinder on the car? If so remove the residual valve from the master and add a 2lb inline valve to the front and a 10lb inline valve to the rear. I have a scarebird kit on my 52 Coronet and this setup has worked well for me.

[48ply1stcar]

1 hour ago, Doug&Deb said:

Do you still have the original master cylinder on the car? If so remove the residual valve from the master and add a 2lb inline valve to the front and a 10lb inline valve to the rear. I have a scarebird kit on my 52 Coronet and this setup has worked well for me.

I also converted to disc with a Scarebird kit on my 48.  I also swapped my rear axle to a 2000 Dakota 3:55.  I only removed the residual valve in the Master Cylinder.  Although my brakes seem to work fine you have me thinking about adding residual valves.

[48ply1stcar]

12 hours ago, Wayaroundit2 said:

I did contact them an it's a separate part. He just wrote back an said it also needs in each front line a  2 PSI Residual Valve it makes sense because the rear take 8 to 10 lb an disk take 3 to 5 . I was told the proportion valve is to direct most pressure to rear drums an residual holds a 2 psi for the front an will hold back pressure for the calapers.  I will try a 2psi residual on each disk line . Thanks for reply all locked up here !

Start by just removing the residual valve if you are still using the original master cylinder.  The valve is nothing more than a washer in the rear of the master cylinder.  After removing the valve you may have not only have to bled the brakes but also the "bench bled" the master cylinder.  Bench b;eeding the MC can be done without removing the MC by removing the brake lines plugging the outlets.  Then simply fill and pump out the air with the brake pedal.  There is good info in this thread.  

 

[Sniper]

Proportioning valves do nothing for front brake lock up.  They are there to control/fix rear brake lock up.

 

If your fronts are locking up and the rears don't then I have to ask, did you adjust your rear brakes?  They are not self adjusting and may be worn with excessive shoe to drum clearance.

 

Residual pressure valves are only needed in the front if you have a problem with the front brakes being spongy and then only if your M/C is below the caliper.  That can cause a siphon effect that can cause the calipers to retract when not in use necessitating the driver to pump the brakes to get a firm pedal.  If that is not an issue don't run them.

 

Sounds to me like what you really need is not a proportioning valve but rather a combination valve that includes hold off which is design to allow the front discs adn rear drums to apply simultaneously.  Without it symptims like yours are common.

 

https://techtalk.mpbrakes.com/combination-valves/combination-valves

 

 

 

[Wayaroundit2]

I have the residual valves on order 2psi I adjusted the brakes in the rear . I'm going to give that a try should work fine . Thanks for the post. All good advice to experiment with again thanks all

[Adam H P15 D30]

If you run the valves, you need a 2lb for the front and 10lb for the rear.  I run neither and never had a problem

What master cylinder are you running?

[Wayaroundit2]

I'm running the stock master I can see the point for the

 2 psi Residual Valve I think it's something like 8 to 10 for drum and 

2 to 3 for disk from what I have read. Going to try 1 Residual valve for each disk .....will see an thanks to everybody for the help I will post the out come tommrow hope !

[kencombs]

On 4/26/2021 at 5:12 PM, Wayaroundit2 said:

Converted my front brakes to the DCM disk conversion kit. I needed a brake Proportioning Valve to evenly distribute the fluid because the disks lock up.  My question is where does it go there is an In & Out does the Proportioning Valve go on the out of the master cylinder or do I need one for each disk brake ? One thing I'm not is a Proportioning Valve wizard any help?

Can you elaborate on the red statement .  Locking up on normal pedal pressure, panic stop or????

Edited April 29, 2021 by kencombs

[Wayaroundit2]

Sure the brakes are fine to much pressure from master keep it so the calipers wont releases.  Fine kit couldent be happier just the dummy that installed it that be me didnt give it a thought. 

[48ply1stcar]

No matter what you do, you still have to remove the residual valve in the master cylinder.  So do that then try the brakes. Seriously, I'm still using the original master cylinder and that's what I did.

[Doug&Deb]

If you decide to run inline residual valves you don’t need one to each disc. Run a 2lb to the front and a 10lb to the rear. I used the shortest pre made nickel copper lines available at the local parts store. The valves need to be close to the master cylinder. You do need to remove the residual valve from the master though. 10lbs is too much pressure for the discs.