 T fitting instead of prop. valve, what is the rational? |
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| DanT |
  Dec 1 2005, 08:18 PM
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Going back to the Dark Side!  Group: Members Posts: 4,300 Joined: 4-October 04 From: Auburn, CA Member No.: 2,880 Region Association: None  |
Ok, I know this has probably been discussed in many threads before. But, what is the reasoning for replacement of the Prop. valve with the "T" fitting for the rear brakes. Does the prop. valve cause more line pressure to the fronts or the rears when it is operating properly? I want to understand the engineering aspects of this modification.
I will be running "M" calipers with mythical billet hubs in the front and stock 914-4s in the rear. thanks (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) |
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| McMark |
Dec 1 2005, 08:33 PM
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
The prop valve limits the amount of hydraulic pressure going to the rear calipers. The T fitting doesn't. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
Long answer, the prop valve has a spring in it. For the first part of the pedal travel the hydraulic pressure is less than the spring rate. As you push the pedal farther the hydralic pressure eventually equals and then surpasses the spring. As the spring moves it closes a valve which completely cuts off any more possible pressure to the rear calipers. Once you release the pedal, the spring decomresses and the valve opens and the rear calipers release. That spring/valve action is one of the reasons the rear calipers/ P-valve are so hard to bleed. |
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Posts in this topic
Dan (Almaden Valley) T fitting instead of prop. valve Dec 1 2005, 08:18 PM
rick 918-S Here's my spin on the deal. I'm running la... Dec 1 2005, 08:33 PM Headrage Jeez!!!
http://www.914world.com/bbs2... Dec 1 2005, 10:59 PM Dan (Almaden Valley) I am sure the reasoning behind the T is that putti... Dec 1 2005, 10:59 PM rick 918-S Dec 1 2005, 11:21 PM Dan (Almaden Valley) ... Dec 1 2005, 11:26 PM Brando Also keep in mind that with much better gripping t... Dec 1 2005, 11:35 PM McMark You mean, this graph Dave? http://... Dec 1 2005, 11:38 PM McMark Dec 1 2005, 11:42 PM trekkor Good thread. http://www.914worl... Dec 2 2005, 12:15 AM J P Stein Dec 2 2005, 07:15 AM andys Dec 2 2005, 10:52 AM Dave_Darling <... Dec 2 2005, 10:55 AM J P Stein Dec 2 2005, 11:22 AM andys ... Dec 2 2005, 11:39 AM kdfoust <... Dec 2 2005, 12:19 PM J P Stein Dec 2 2005, 01:39 PM nick mironov This is where I got my T-fitting ($8):
http:... Dec 2 2005, 02:04 PM horizontally-opposed Eric... http://www.914world.co... Dec 2 2005, 02:06 PM andys Dec 2 2005, 03:14 PM Eric_Shea First Post... http://www.914world.... Dec 2 2005, 05:20 PM J P Stein Brakes......a decent buy:
http://forums.pelicanpar... Dec 3 2005, 10:46 AM horizontally-opposed ... Dec 3 2005, 01:19 PM SirAndy Dec 3 2005, 02:12 PM nine14cats Hi Dan,
I'll give you what Doris and I were r... Dec 3 2005, 03:20 PM
J P Stein Basicaly, what Bill, Andys & I are talking about i... Dec 3 2005, 04:46 PM |
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