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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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| sww914 |
Jul 15 2008, 12:55 PM
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#2
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Advanced Member ![]() ![]() ![]() ![]() Group: Members Posts: 2,439 Joined: 4-June 06 Member No.: 6,146 Region Association: None |
I wouldn't automatically blame the proportioning valve yet. If you've just rebuilt the calipers, replaced the pads, and turned the rotors, you will often have a somewhat spongy pedal for a while. The pads and the rotors are not yet making full contact on their faces because they need to wear into each other a bit, and the caliper pistons will need to smash through the paint and/or insulating material on the back of the pads. The just replaced calipers may also not be sitting perfectly true and square due to little bits of grit or corrosion on the mounting surfaces, but they will work their way into a solid position after some use.
Also, you didn't mention having gone through the fun process of adjusting the air gap on the rear pads for the parking brake, if that's maladjusted it will give you a long pedal. If the pistons in the calipers are clocked at the wrong angle, the high part of the lip on the piston will push more on one side of the pads than the other, as it's designed to, but in the wrong spot, thus wearing the pads unevenly. This should be corrected as it will shorten pad life significantly and it will take longer to get a firm pedal until the pads have worn flat to the rotors which would be at an odd angle in relation to the brake pad backing plate. As you can see, there are several potential problems that a tee won't address. |
| Wanna9146 |
Jul 15 2008, 08:13 PM
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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 |
I wouldn't automatically blame the proportioning valve yet. If you've just rebuilt the calipers, replaced the pads, and turned the rotors, you will often have a somewhat spongy pedal for a while. The pads and the rotors are not yet making full contact on their faces because they need to wear into each other a bit, and the caliper pistons will need to smash through the paint and/or insulating material on the back of the pads. The just replaced calipers may also not be sitting perfectly true and square due to little bits of grit or corrosion on the mounting surfaces, but they will work their way into a solid position after some use. Also, you didn't mention having gone through the fun process of adjusting the air gap on the rear pads for the parking brake, if that's maladjusted it will give you a long pedal. If the pistons in the calipers are clocked at the wrong angle, the high part of the lip on the piston will push more on one side of the pads than the other, as it's designed to, but in the wrong spot, thus wearing the pads unevenly. This should be corrected as it will shorten pad life significantly and it will take longer to get a firm pedal until the pads have worn flat to the rotors which would be at an odd angle in relation to the brake pad backing plate. As you can see, there are several potential problems that a tee won't address. The pedal is beyond "spongy". It goes almost to the floor. The car will only stop after some pumping and there is no way it will lock-up the brakes for a sudden stop. I'll dismantle the proportioning valve and inspect/clean. That's really the only thing left that hasn't been addressed. Perhaps it is preventing a full bleed...? |
| sww914 |
Jul 15 2008, 08:23 PM
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#4
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Advanced Member ![]() ![]() ![]() ![]() Group: Members Posts: 2,439 Joined: 4-June 06 Member No.: 6,146 Region Association: None |
I wouldn't automatically blame the proportioning valve yet. If you've just rebuilt the calipers, replaced the pads, and turned the rotors, you will often have a somewhat spongy pedal for a while. The pads and the rotors are not yet making full contact on their faces because they need to wear into each other a bit, and the caliper pistons will need to smash through the paint and/or insulating material on the back of the pads. The just replaced calipers may also not be sitting perfectly true and square due to little bits of grit or corrosion on the mounting surfaces, but they will work their way into a solid position after some use. Also, you didn't mention having gone through the fun process of adjusting the air gap on the rear pads for the parking brake, if that's maladjusted it will give you a long pedal. If the pistons in the calipers are clocked at the wrong angle, the high part of the lip on the piston will push more on one side of the pads than the other, as it's designed to, but in the wrong spot, thus wearing the pads unevenly. This should be corrected as it will shorten pad life significantly and it will take longer to get a firm pedal until the pads have worn flat to the rotors which would be at an odd angle in relation to the brake pad backing plate. As you can see, there are several potential problems that a tee won't address. The pedal is beyond "spongy". It goes almost to the floor. The car will only stop after some pumping and there is no way it will lock-up the brakes for a sudden stop. I'll dismantle the proportioning valve and inspect/clean. That's really the only thing left that hasn't been addressed. Perhaps it is preventing a full bleed...? That sounds like a long pedal. Did you adjust the air gap on on the rear pads? |
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
r_towle The proportioning valve is really a simple piston ... Jul 15 2008, 10:29 AM
Wanna9146
The proportioning valve is really a simple piston... Jul 15 2008, 10:37 AM
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
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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