2005 Proportioning Valve?

[Kim57]

Hi guys
I hang in the 47 to 59 secton because I'm building a 57 pro street truck.
I have a hydroboost/master cylinder off of a 2005 chevy truck and am confused on the proportioning valve.
There wasn't one on the donor truck and I have no idea if its built into the master or if they did something else.
My local dealership showed no listing for one.
I have a combo distribution/prop. valve that I think will work if I need to use one.
Hope someone in this section can help me out with this.
Thanks.
Kim

[clinebarger]

On a 05 the Rear Proportioning is cotrolled by the ABS modulator.

The 05 master will put out a large volume of fliud. What master cylinder you use needs to be based on what braking system you have (4 wheel disc, disc/drum, 4 wheel drum). On a custom app. I whould use a adjustable proportioning valve for the rear. Several companies make them like Wilwood, SSBC, Bear, etc..

[Kim57]

Originally Posted by clinebarger

On a 05 the Rear Proportioning is cotrolled by the ABS modulator.

The 05 master will put out a large volume of fliud. What master cylinder you use needs to be based on what braking system you have (4 wheel disc, disc/drum, 4 wheel drum). On a custom app. I whould use a adjustable proportioning valve for the rear. Several companies make them like Wilwood, SSBC, Bear, etc..

Thanks for the response.
I kinda figured that is what they did as all the lines from the master went into a computerized box and then came back out.
I'm running 4 wheel discs and made sure the truck I got the unit off had them also.
thanks again.
Kim

[clinebarger]

Originally Posted by Kim57

Thanks for the response.
I kinda figured that is what they did as all the lines from the master went into a computerized box and then came back out.
I'm running 4 wheel discs and made sure the truck I got the unit off had them also.
thanks again.
Kim

Running a hydroboost & a high volume master can make your brakes over sensitive without the correct pedal geometry. Are you mounting it on the firewall or under the floor like it was?

[Kim57]

Originally Posted by clinebarger

Running a hydroboost & a high volume master can make your brakes over sensitive without the correct pedal geometry. Are you mounting it on the firewall or under the floor like it was?

It's being set up under the cab. Here's a link to a page in my build thread with pics of what I'm doing. I checked out wilwoods prop valve and will probably go with it as that's what my rear brakes are. If I need to change the master I will do that also.
http://67-72chevytrucks.com/vboard/s...=283107&page=8
Kim

[clinebarger]

Originally Posted by Kim57

It's being set up under the cab. Here's a link to a page in my build thread with pics of what I'm doing. I checked out wilwoods prop valve and will probably go with it as that's what my rear brakes are. If I need to change the master I will do that also.
http://67-72chevytrucks.com/vboard/s...=283107&page=8
Kim

Very nice! I agree with the other posters on the rod needing to be chromemoly. You will also need 2 pound residual valves installed in the main feed lines front & rear.......When the master cylinder is at the same level or lower than the calipers the pistons can retract from the pads & return fluid to the master, If that happens the pedal will go to the floor on the first hit after sitting or after a long drive on the highway. Very dangerous.

[Kim57]

Originally Posted by clinebarger

Very nice! I agree with the other posters on the rod needing to be chromemoly. You will also need 2 pound residual valves installed in the main feed lines front & rear.......When the master cylinder is at the same level or lower than the calipers the pistons can retract from the pads & return fluid to the master, If that happens the pedal will go to the floor on the first hit after sitting or after a long drive on the highway. Very dangerous.

Thanks.
I've already got the residual valves and I'am planning on the chromemolly.
Kim

[mcmlxix]

Bringing back an old thread. I have the MC and hydroboost off a '05 Silverado 2500hd. I need to know which port on the factory 05 master is for the front and which is for the rear....

[clinebarger]

...

[mcmlxix]

Originally Posted by clinebarger

...

Thanks... I had a feeling they were "reversed" ....