Visit The Dirt Forum for More Information

Author Topic:   Removing proportioning valve on metric car.
Raceman17
Dirt Maniac

Total posts: 165
posted April 08, 2005 06:41 PM  
I removed the proporting valve on my car and I am trying to find the correct fittings to splice the rear brake line coming out of the master cylinder into the rear line that was connected to the rear part of the proporting valve. The fitting for the rear line coming off of the master cylinder is a 5/16 male fitting and the one coming off of the rear of the proporting valve is something bigger. I got a adapter that was 5/15 to 3/8 and the 3/8's part was too big. Is that line coming from the rear part a metric fitting. How are yall removing the proporting valve and splicing them together. Are you using compression fittings instead of flared fittings? Any help would be appreciated.
Thanks

o5racer
Dirt Freak

Total posts: 402
posted April 08, 2005 08:35 PM  
The easyiest way is to just cut the odd size fittings off and get regular 3/16 and 1/4 fittings and reflare the ends of the line. Its a real pain to get all the right adapters but it is possible.
Nick

Raceman17
Dirt Maniac

Total posts: 165
posted April 08, 2005 09:04 PM  
quote:
Originally posted by o5racer:
The easyiest way is to just cut the odd size fittings off and get regular 3/16 and 1/4 fittings and reflare the ends of the line. Its a real pain to get all the right adapters but it is possible.
Nick

Would the tube that needs to be flared a single or a double flare?


juni
Dirt Maniac

Total posts: 184
posted April 09, 2005 06:16 AM  
Double on brak lines


rico 08
Dirt Forum Champ
Total posts: 1139
posted April 09, 2005 06:23 AM  
I used compression fittings like you are not supposed to do...they do leak a little.

iowatoolman
Dirt Freak

Total posts: 369
posted April 09, 2005 12:05 PM  
GLAD I DON'T RACE AGAINST YOU
i would be in fear for my life

DON'T SCRIMP ON SAFETY DO IT RIGHT

they make the lines to adapt it you just have to know what to look for i did it last year but as to the sizes and **** i don't remember
if all else fails double flare the right size tubing nut on the tube and get a brake union to connect the lines

drive hard or drive home

crc1124
Dirt Maniac

Total posts: 143
posted April 09, 2005 12:14 PM  
I just replaced the whole line going to the rearend. I just figured that I could trust it better. I wouldn't trust the old factory lines above the frame rail. I just switched my rears to disc this year also. I've replaced all of my brake lines now. Still waiting to try them out.
I agree, don't skimp on safety!! You could hurt alot more people than just yourself. Imagine heading into turn 1 tap the pedal and it goes to the floor?

[This message has been edited by crc1124 (edited April 09, 2005).]

DangerZoneRacing
Dirt Maniac

Total posts: 176
posted April 09, 2005 05:44 PM  
Guess I'm not much for brake systems.....what would removing the proportioning valve do? any benefits on a 1/3 mile asphalt? thanks guys.

mikekuhlman
Dirt Full Roller

Total posts: 34
posted April 09, 2005 06:34 PM  
the rear line has a metric fitting

rico 08
Dirt Forum Champ
Total posts: 1139
posted April 10, 2005 06:48 AM  
You can do it you just have to know what you are doing,done it a thousand times but i don't advise it.
And toolman since you race figure 8's i feel the same as you

iowatoolman
Dirt Freak

Total posts: 369
posted April 10, 2005 10:51 AM  
yes your right i do race figure 8's and safety is always at the top of my list. but it should be on everyones do you know how many guys have been killed or seriously hurt racing circle track? last year there were 3 that i knew of do you know how many figure 8 racers were hurt (none at the track i race at) BUT WE ALL TAKE THAT CHANCE OF BEING HURT SO LETS ALWAYS PUT SAFETY ON THE TOP OF THE LIST!!!!

drive hard or drive home

DangerZoneRacing
Dirt Maniac

Total posts: 176
posted April 11, 2005 02:00 PM  
Nobody has a answer to why you would remove the proportioning valve? I would like to also know the advantages and if it would do any good on a 1/3 mile asphalt oval? thanks.

iowatoolman
Dirt Freak

Total posts: 369
posted April 11, 2005 09:18 PM  
you remove the proportioning valve to get more rear brake percentage to help set the car into the corner

drive hard or drive home

DangerZoneRacing
Dirt Maniac

Total posts: 176
posted April 12, 2005 07:24 AM  
thank you toolman.

powerglides
Dirt Freak

Total posts: 374
posted April 13, 2005 05:18 AM  
How does removing the proportioning valve give you more rear %?

rico 08
Dirt Forum Champ
Total posts: 1139
posted April 13, 2005 06:06 AM  
The car makers use the prop valve to limit the rear brake so when grandma slams on the brakes the rear ones dont lock up and the car loose control
but thats what we like

powerglides
Dirt Freak

Total posts: 374
posted April 13, 2005 11:07 AM  
My understanding is it puts the first few hundred pounds to the REAR wheels and then the front to keep the front from locking up before the rear. Maybe I will attach pressure gages to mine and find out once and for all what the story is and report back

Mikey14
Dirt Freak

Total posts: 265
posted April 13, 2005 01:30 PM  
instead of refitting we just changed the line from the MC to the line on the back side of the prop. valve. $6 and no flaring or fittings to mess with.

petordragon
Dirt Maniac

Total posts: 167
posted April 18, 2005 06:45 AM  
proportioning valve does not change pressure. It is saftey dedevice for when you have a massive fluid leak. when the pressure to one end of the car (front or rear) looses pressure (busted line) it shuts off flow to that system and only sends it to the end that is maintaining pressure.

powerglides
Dirt Freak

Total posts: 374
posted April 20, 2005 04:42 AM  
petor,
Can you tell us where to find this info in print?

petordragon
Dirt Maniac

Total posts: 167
posted April 20, 2005 06:25 PM  
hope this helps. http://www.inlinetube.com/pro_valves.htm

Back to the Archives