Help needed with installing a rear brake line prroportioning Valve

[MADMAX]

I'm trying to install a Wilwood Proportioning Valve on the rear brake line of my 96 GTS to enable fine throttle adjustment of the rear brakes.
Has anyone got any experience of doing this type of job because I’m struggling with finding the right size brake pipe fittings or anyone that supplies them. Connecting to the unusual pipe-nut size on the Viper (½” UNF I think) is also becoming a challenge.

Your advice would be much appreciated.

Here's what I've come up with so far.
I've looked at two options:-
Option 1) Cutting the existing steel brake line and making good the ends with new pipe-nuts and flares.
PROBLEM:- I've heard flaring steel tube is not easy, least of all when it’s still fitted to the car. This forces option 2 ……. which also has problems …….

Option 2) Unscrew the rear brake line outlet port on the differential valve (½” UNF), fit it to the new proportioning valve outlet (not ½” UNF so adapter needed) and fit a new length of brake line between the differential valve rear brakes outlet port and the new proportioning valve inlet – are you still with me? The prop valve ports are female 1/8” NPT by the way.
ADVANTAGE:- Don’t need to cut any brake lines fitted in the car – but you do need to do a little pipe bending.
PROBLEM:- I can’t find anyone that supplies the ½” UNF pipe nuts (for the new length of brake line) and I can’t find anyone that supplies a female ½” UNF adapter (to go on the ½” pipe nut presently installed on the rear brake line).

Finally, the Wilwood proportioning valve (part # 260-8419) is supplied with two BRASS 1/8" NPT to 3/8" UNF inverted flair fittings – supplying the right size fittings with the valve is a great idea but I’d rather they were in STEEL, not brass.

So I need to add 2 x STEEL 1/8" NPT to 3/8" UNF inverted flair fittings to my shopping list.

If anyone has any help, advice or experience on doing this type of job, I’m all ears.

Best regards, from across the pond - Ade.

 

[SNKEBIT]

Cut the line and make new flares. (double flare for brake lines.) Also, I have done hundreds of repairs/new lines and never had a problem w/ the brass fittings. Actually, I think some of the fittings just look like brass, might be coated steel to prevent corrosion.

 

[JonB]

Please, PLEASE tell us you are NOT installing a rear prop valve on a '96 with OE Brakes ?!?! "S C A R Y "
If so, my best advice is: STOP! DONT !!

...I'm trying to install a Wilwood Proportioning Valve on the rear brake line of my 96 GTS to enable fine throttle adjustment of the rear brakes.................
...If anyone has any help, advice or experience on doing this type of job, I’m all ears.
Best regards, from across the pond - Ade.

 

[Red Snake]

My car already had the proportioning valve installed when I bought the car (SRT fronts and Gen II fronts moved to back). The valve was installed under the hood near the drivers side frame rail. I am not sure if this info does you any good but I can take some pics if it would help.

 

[MADMAX]

Re: Help needed with installing a rear brake line proportioning Valve

Please, PLEASE tell us you are NOT installing a rear prop valve on a '96 with OE Brakes ?!?! "S C A R Y "
If so, my best advice is: STOP! DONT !!

OKAY - thanks JonB.
Here you go:
"I am NOT installing a rear prop valve on a '96 with OE Brakes"
That makes me feel better too.
Prop v/v installation is part of the Winter project that will also see rear brakes upgraded. Other improvements include braded hoses, fascia cooling duct, front calliper cooling ducts and finally a soft drink holder .....
I might need to talk to you about pipe fittings?????

 

[VIPER BAZ UK]

The BBD Prop valve came with new lines as a bolt in fit.. Jon B now sells them,, Easy job... Just be carefull where all the brake fluid goes when removing the old one....

 

[GTS Dean]

Brake mods on a Viper should begin with a thorough, objective assessment of your intended driving envelope, as well as your own mechanical and driving abilities. The stock brake system, coupled with some extremely modest, proven modifications will provide MAJOR track performance improvements with as little as $1200-1500 invested. Top quality brake fluid, teflon/stainless lines, quality friction compounds, good rotors, effective cooling, an OEM rear caliper upgrade and disabling of the stock proportioning valve can be done by yourself for the above-suggested budget.

If you are considering upsizing the rotors and calipers, then you should consult with reputable companies that have ENGINEERED solutions for VIPER automobiles. There are countless threads on this forum covering every combination under the sun. There are relatively few solid performers, but many, many failed attempts at improvement.

If the brake piston area and rotor effective radius is properly matched, then the only need for an adjustable prop valve is adjusting for tire size changes, varying fuel load and wet/dry pavement under racing conditions. The vast majority of people misuse an adjustable valve to make up for fundamental lack of understanding of brake and vehicle dynamics, and just want something that "looks really cool."

DO YOUR HOMEWORK BEFORE SPENDING MONEY.

 

[RTTTTed]

I would cut and double flare my brakeline. If you've never used one before have someone with experience show you how to do it.

It's way too important for any mistakes.

Ted

 

[Tom F&L GoR]

Some minor comments:

If you can buy the same diameter steel brake line as on the car, do so and cut one end off. Practice making the flare. Sacrifice it to learn and get comfortable with doing it.

Use a magnet to see if the brass is brass or not.

 

[MADMAX]

Re: Help needed with installing a rear brake line proportioning Valve

Many thanks for the great advice everyone - definitely helping me sort out a way forward.