Installing a brake prop valve, easy process?

Sixty7Restomod

New Member

Oct 13, 2008

23

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1

The Bay Area

Jul 5, 2011

#1

• Jul 5, 2011

• #1

Hey everybody, I did a grande front disc brake conversion and when pressing down ever so slightly on the brakes it's so sensitive I can't help but to jerk forward. After researching the forums I ordered a prop valve. Is it a easy process adding it to the brake system? I want to tackle the install myself but definitely don't want to make a mistake with such a critical part of the car being that I must be able to stop lol. Out of curiosity I called and asked the local classic mustang mechanic and he said he would charge me $250 for the install. Is this right?

 

robbz28

Member

Sep 23, 2009

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Epps, LA

Jul 5, 2011

#2

• Jul 5, 2011

• #2

This is one of those jobs even the handiest of handy men sometimes choose to outsource. A lot of guys (myself included) use a GM disc/drum proportioning valve...I was able to use most of my original lines, but you MUST have the proportioning valve secured (don't let it be just held in place by the lines themselves) it also may require some bending and flaring of pipe (some guys are unsure of flaring lines, hence why they outsource) but if you have a double inverted flare tool and a little know-how its not a bad job.

 

6

67rcks

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Feb 20, 2008

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Jul 6, 2011

#3

• Jul 6, 2011

• #3

save time and avoid flaring, buy machine-made brake lines if you can

 

robbz28

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Sep 23, 2009

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Epps, LA

Jul 6, 2011

#4

• Jul 6, 2011

• #4

67rcks said:

save time and avoid flaring, buy machine-made brake lines if you can

Click to expand...

This is true...most parts houses carry pre flared lines in varying lengths, just make sure you buy them long enough to bend a flex point (loop) in the lines...if its a line running from a point of vibration (master cylinder) to a fixed point (fender well) there MUST be a loop in the line, or else the vibration can crack the flare and leak and you will have no brakes (ask me how I know) anyway, just something to keep in mind.

 

robbz28

Member

Sep 23, 2009

775

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Epps, LA

Jul 6, 2011

#5

• Jul 6, 2011

• #5

One more thought I had....Im not a fan of the adjustable proportioning valve, but it would probably be an easier install and will work just fine. In fact I think I have one I might can let you have really cheap (if I can find it). All you have to do is buy one small joint of line and install this behind the old distribution block (I believe to the rear brakes).

 

Sixty7Restomod

New Member

Oct 13, 2008

23

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1

The Bay Area

Jul 6, 2011

#6

• Jul 6, 2011

• #6

Thanks for the advice guys. I'm going to attempt trying the install myself. Its a learning experience. Its gonna make me love my stang that mush more lol.

 

65fastbackresto

Active Member

Apr 13, 2007

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AR

Jul 6, 2011

#7

• Jul 6, 2011

• #7

It`s pretty easy, you can do it.

I also have the granada setup and did my own plumbing. I would suggest a residual pressure valve in the line going to the back brakes, I have a 10 lb one, and it helps keep the springs from pulling the pads away from the brake drums.

Warning, this job is frustrating, you can`t seem to get your hands or wrenches exactly where you want them, when it pisses you off, and it will, walk away slowly......and come back later. LOL

 

mtaqua

Member

Oct 7, 2006

345

4

19

Jul 6, 2011

#8

• Jul 6, 2011

• #8

I'd say not to bad, of all the things I've done to the car. I installed explorer rear disc, CSRP up front, all from scratch (nothing installed on the car). I used an adjustable prop, added a line lock. I ordered some pre-bent lines, of which all were modified (re-bent or cut and re-flared). Flaring is straight forward, google a you-tube video. I used a 2000 V6 mustang master cylinder, which had metric flares. So I bought metric flared tube (with fittings), and cut it in half and added standard flares to plumb into my other stuff (the line dia is the same, just different flares and fittings on the ends). All that being said I haven't driven the car. I was able to bleed the brakes, there are no leaks, and there seems to be firm pedal pressure, we'll see.

 

R

RagHead

Member

Sep 7, 2008

35

6

19

West Monroe, Louisiana

Jul 7, 2011

#9

• Jul 7, 2011

• #9

I used a adjustable PV on my setup as it was easier to plumb and work with with the motor and everything in the car. I also used a master cylinder for disc/drum setup and did not use a residual valve. Everything works great.

 

PoppyMod

Member

Jun 27, 2010

617

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Severna Park, MD

Jul 8, 2011

#10

• Jul 8, 2011

• #10

Sixty7Restomod said:

Hey everybody, I did a grande front disc brake conversion and when pressing down ever so slightly on the brakes it's so sensitive I can't help but to jerk forward. After researching the forums I ordered a prop valve. Is it a easy process adding it to the brake system? I want to tackle the install myself but definitely don't want to make a mistake with such a critical part of the car being that I must be able to stop lol. Out of curiosity I called and asked the local classic mustang mechanic and he said he would charge me $250 for the install. Is this right?

Click to expand...

Hi,
Having "been there done this"....
After the great advice already offered, you'll need to begin the adjusting process. Preliminary conventions, say to have about 900-1100 lbs pressure to the front and about 600-800 to the rear. How do you get there? You can buy a testing kit that is plugged into the bleed screw and read pressure, or, find an empty lot, do a number of panic stops, all the while, adjusting the pressure to the rear brakes. Just in case it it isn't known, the Prop valve is plumbed into the rear brake system. Anyway, adjust the pressure to the drums to a point just before they lock, in your panic stop. You don't want them to lock before to coming to a complete stop.
Hope this helps!