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| Wanna9146 |
Jul 14 2008, 10:10 PM
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#1
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Member ![]() ![]() Group: Members Posts: 235 Joined: 19-January 08 From: Florida Member No.: 8,595 Region Association: South East States |
I read on this forum recently about someone swapping out their proportioning valve for a "T" fitting.
Does anyone know the size/thread count of the correct "T" fitting? Any fabrication required? |
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| r_towle |
Jul 15 2008, 10:29 AM
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#2
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Custom Member ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States
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The proportioning valve is really a simple piston and spring.
I have never met a bad one. If you still have mushy brakes its because you have not bled the air THROUGH the proportioning valve. This is not as easy as it sounds. the spring requires 750 PSI to activate, and most people dont get that when bleeding brakes. It can be done using the old school two person brake bleeding system, but honestly I have never had success with that, nor a power bleeder, nor a miti vac bleeder. The reason I suspect that I have never had success is because I am the bleeder, not the pumper. If I was pumping, I would pump them till they were firm and then try to push the pedal through the floor...that will do it. The only way I know I have rid myself of the nasty bubble is to bleed them the best I can, then go for a ride and STOMP on the brakes about ten times...this produces the required PSI to move the air past the valve. Then I go home and bleed them again, and I am all set to go. Be careful because when you finally get the air bubble past the valve, it will feel like you have almost no brakes at all...pedal to the floor. I stay close to home...its a ten minute ride. Rich |
| Wanna9146 |
Jul 15 2008, 10:37 AM
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#3
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Member ![]() ![]() Group: Members Posts: 235 Joined: 19-January 08 From: Florida Member No.: 8,595 Region Association: South East States |
The proportioning valve is really a simple piston and spring. I have never met a bad one. If you still have mushy brakes its because you have not bled the air THROUGH the proportioning valve. This is not as easy as it sounds. the spring requires 750 PSI to activate, and most people dont get that when bleeding brakes. It can be done using the old school two person brake bleeding system, but honestly I have never had success with that, nor a power bleeder, nor a miti vac bleeder. The reason I suspect that I have never had success is because I am the bleeder, not the pumper. If I was pumping, I would pump them till they were firm and then try to push the pedal through the floor...that will do it. The only way I know I have rid myself of the nasty bubble is to bleed them the best I can, then go for a ride and STOMP on the brakes about ten times...this produces the required PSI to move the air past the valve. Then I go home and bleed them again, and I am all set to go. Be careful because when you finally get the air bubble past the valve, it will feel like you have almost no brakes at all...pedal to the floor. I stay close to home...its a ten minute ride. Rich Yep, I've tried all this (contrary to the other posters in this thread who think I'm a dumbass who doesn't do his research). So, I'm assuming (shhh...don't tell "Rhodyguy" I'm assuming something...he doesn't approve!) the proportioning valve is stuck solid. The calipers & master cylinder were totally gunked-up. I didn't even think about removing the proportioning valve when I had everything apart (as you said...it's just a simple spring/piston...not much to go wrong). As I have to move the car around, I figure I'll throw in the "T" so at least it's driveable until I do my 911 brake conversion (sooner/later). Can the proportioning valve be "saved" by removing/cleaning? Not sure what's involved in a rebuild...(off to do more homework) |
Wanna9146 Swapping proportioning valve for "T" fitting... Jul 14 2008, 10:10 PM
ClayPerrine
I read on this forum recently about someone swapp... Jul 14 2008, 10:34 PM
smg914 You can also purchase the same "T" fitti... Jul 14 2008, 10:47 PM
Krieger914
You can also purchase the same "T" fitt... Jul 14 2008, 10:51 PM
Wanna9146
I upgraded front brakes to BWM calipers and did ... Jul 14 2008, 10:55 PM
r_towle
I upgraded front brakes to BWM calipers and did... Jul 15 2008, 09:25 AM
Wanna9146 The stock system is designed very well, and the Pr... Jul 15 2008, 09:50 AM
Wanna9146 Would it be P/N 914.355.667.00 ? Jul 14 2008, 10:54 PM
904svo Where at in Ga. do you live? I have a spare T you ... Jul 15 2008, 08:53 AM
Wanna9146
Where at in Ga. do you live? I have a spare T you... Jul 15 2008, 09:48 AM
904svo
Where at in Ga. do you live? I have a spare T yo... Jul 15 2008, 10:08 AM
Wanna9146
This T fitting was located in the front brake cir... Jul 15 2008, 10:10 AM
brant have fun spinning off the road backwards into the ... Jul 15 2008, 09:43 AM
Wanna9146
have fun spinning off the road backwards into the... Jul 15 2008, 09:51 AM
brant
have fun spinning off the road backwards into th... Jul 15 2008, 11:01 PM
rhodyguy i've never quite understood the reasoning for ... Jul 15 2008, 09:54 AM
Wanna9146
i've never quite understood the reasoning for... Jul 15 2008, 09:56 AM
rhodyguy ok. what do you figure a known good used valve cos... Jul 15 2008, 10:02 AM
Wanna9146
ok. what do you figure a known good used valve co... Jul 15 2008, 10:06 AM
Wanna9146
ok. what do you figure a known good used valve co... Jul 15 2008, 10:23 AM
rhodyguy happy motoring.
k Jul 15 2008, 10:09 AM
Wanna9146
happy motoring.
k
If I do this swap, I'll ... Jul 15 2008, 10:13 AM
SirAndy
Anyone taking bets that the car won't stop in... Jul 15 2008, 01:19 PM
Wanna9146
Anyone taking bets that the car won't stop i... Jul 15 2008, 08:15 PM
davesprinkle
The proportioning valve is really a simple piston... Jul 16 2008, 09:27 AM
brant its emergency situations when the brakes will surp... Jul 15 2008, 12:08 PM
sww914 I wouldn't automatically blame the proportioni... Jul 15 2008, 12:55 PM
Wanna9146
I wouldn't automatically blame the proportion... Jul 15 2008, 08:13 PM
sww914
I wouldn't automatically blame the proportio... Jul 15 2008, 08:23 PM
r_towle
The pedal is beyond "spongy". It goes a... Jul 15 2008, 08:25 PM
Wanna9146 Thanks, I'll give this a shot.
BUT
Try this ... Jul 15 2008, 09:25 PM
Lavanaut People here are trying to help you out with real, ... Jul 15 2008, 01:22 PM
jmill After doing quite a bit of research on this topic ... Jul 15 2008, 01:40 PM
Eric_Shea
Make sure your steering wheel is straight otherw... Jul 15 2008, 08:41 PM
Wanna9146 Thanks Eric, but don't worry about the "T... Jul 15 2008, 09:14 PM
Cap'n Krusty Spongy brakes after rebuilding the calipers is a p... Jul 15 2008, 09:02 PM
Wanna9146 If you go back and read, I only responded negative... Jul 15 2008, 09:16 PM
904svo Read this, It will explain the problems if you ins... Jul 15 2008, 09:58 PM
Eric_Shea Man I wish that article would go away but... it wo... Jul 15 2008, 10:29 PM
70Sixter Eric and brant both mentioned tapping on the p-val... Jul 16 2008, 09:31 AM
rhodyguy the adj valve is a SUPER idea! :headbanger: b... Jul 16 2008, 09:41 AM
roadster fan
the adj valve is a SUPER idea! :headbanger: ... Jul 16 2008, 03:37 PM
Eric_Shea Dave, did you get it working the way you'd lik... Jul 16 2008, 10:22 AM
SlackeR32 I don't mean to hijack, but since everyone is ... Jul 16 2008, 10:32 AM
Phoenix 914-6GT I have a T fiting in mine. What should I have?
I... Jul 16 2008, 06:19 PM
Eric_Shea
You have what are called "Wide A-Calipers... Jul 16 2008, 08:11 PM
davesprinkle
(...lots of insightful braking stuff truncated h... Jul 17 2008, 10:26 AM
SlackeR32 Thank you Eric!
I was a bit confused at fir... Jul 17 2008, 01:03 PM
6freak
You have what are called "Wide A-Calipers... Jul 17 2008, 02:06 PM
Eric_Shea
The threaded adjust rod simply rests against a h... Jul 17 2008, 07:34 PM![]() ![]() |
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