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Pressure valve O-ring size??

 
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MikeDanger  



Joined: 21 Nov 2002
Posts: 774
Location: Denver

PostPosted: Tue Jan 28, 2014 2:12 pm    Post subject: Pressure valve O-ring size?? Reply with quote

anyone know the Spec?
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Rasta Monsta  



Joined: 12 Jul 2006
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Location: PacNW

PostPosted: Tue Jan 28, 2014 2:27 pm    Post subject: Reply with quote

There is a commonly available repair kit for the primary regulator that includes o-rings and a collection of shims for making adjustments...
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MikeDanger  



Joined: 21 Nov 2002
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Location: Denver

PostPosted: Tue Jan 28, 2014 2:31 pm    Post subject: Reply with quote

yes, but i want to pick it up locally, since there are 6 different parts stores down the st from me.
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ideola  



Joined: 01 Oct 2004
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Location: Spring Lake MI

PostPosted: Tue Jan 28, 2014 9:31 pm    Post subject: Reply with quote

The local parts stores are unlikely to have the correct metric size. I do not know what size it is. Why would you not purchase the correct kit? You do realize that you are risking spraying highly pressurized fuel all over your engine bay if the replacement o-ring doesn't fit correctly? Stop looking for short cuts and buy the correct part.
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MikeDanger  



Joined: 21 Nov 2002
Posts: 774
Location: Denver

PostPosted: Tue Jan 28, 2014 9:44 pm    Post subject: Reply with quote

the "kit" some Orings and washers? yeah thats going to be hard to find, better call across the country and have them ship me one tiny oring and washers, SO I have to quit working on this for a whole week.... thanks...
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kcoyle  



Joined: 15 Jan 2011
Posts: 712
Location: Long Island, NY

PostPosted: Wed Jan 29, 2014 12:08 am    Post subject: Reply with quote

Bring old ones into FLAPS?
Harbor freight?
http://www.harborfreight.com/225-piece-metric-nitrile-o-ring-assortment-67609.html

If you're an Amazon prime member I'm sure they sell something you can use and it will be at your door in 2 days.
Keep in mind that this is high pressure.
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ideola  



Joined: 01 Oct 2004
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Location: Spring Lake MI

PostPosted: Wed Jan 29, 2014 3:37 am    Post subject: Reply with quote

As I said, the local hardware is unlikely to have the correct metric o-ring in stock. If you want to waste your time driving around to 10 different stores searching in vain, knock yourself out. Even if you find something that fits, there's still no guarantee it will work correctly. I prefer to do things correctly the first time, and not risk blowing pressurized fuel all over my engine bay, but to each his own.

BTW, to spec it correctly, you need to factor in the following characteristics:
Inner diameter
Outer diameter
Cross-sectional profile
Cross-sectional diameter
Material (must be fuel safe)
"Squish" of the material when compressed to ensure proper sealing

Measuring the old one is not a good plan, as the original o-ring is quite likely to be far out of spec (why else would it need to be replaced). Since this part is not in the Porsche PET, there is no way to get those details from a known good source. So you can either guess your way through it and hope to get it right, or just purchase the damn repair kit that already has that particular O-ring and everything else you are likely to need to rebuild your fuel distributor.

By the way, from your previous post on the CIS test results, it appears that you have some fairly significant leak down on the the circuit, which is usually somewhere in the return line. You only correctly identified one potential culprit (the check valve). More often than not, that kind of pressure loss is caused by a leaking accumulator, which you would have known if you bothered to read the Haynes manual diagnostic section or the Probst source that I cited in my how-to. Or God forbid, done a search here on the forum.

Good luck.
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ideola  



Joined: 01 Oct 2004
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PostPosted: Wed Jan 29, 2014 12:09 pm    Post subject: Reply with quote

And if you think faulty o-rings are no big deal, tell that to NASA.
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Rasta Monsta  



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PostPosted: Wed Jan 29, 2014 4:39 pm    Post subject: Reply with quote

Should have gone for the legos.
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924-76  



Joined: 05 Jun 2006
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PostPosted: Wed Jan 29, 2014 7:51 pm    Post subject: Reply with quote

Rasta Monsta wrote:
Should have gone for the legos.


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MikeDanger  



Joined: 21 Nov 2002
Posts: 774
Location: Denver

PostPosted: Thu Jan 30, 2014 5:20 pm    Post subject: Reply with quote

ideola wrote:
As I said, the local hardware is unlikely to have the correct metric o-ring in stock. If you want to waste your time driving around to 10 different stores searching in vain, knock yourself out. Even if you find something that fits, there's still no guarantee it will work correctly. I prefer to do things correctly the first time, and not risk blowing pressurized fuel all over my engine bay, but to each his own.

BTW, to spec it correctly, you need to factor in the following characteristics:
Inner diameter
Outer diameter
Cross-sectional profile
Cross-sectional diameter
Material (must be fuel safe)
"Squish" of the material when compressed to ensure proper sealing

Measuring the old one is not a good plan, as the original o-ring is quite likely to be far out of spec (why else would it need to be replaced). Since this part is not in the Porsche PET, there is no way to get those details from a known good source. So you can either guess your way through it and hope to get it right, or just purchase the damn repair kit that already has that particular O-ring and everything else you are likely to need to rebuild your fuel distributor.

By the way, from your previous post on the CIS test results, it appears that you have some fairly significant leak down on the the circuit, which is usually somewhere in the return line. You only correctly identified one potential culprit (the check valve). More often than not, that kind of pressure loss is caused by a leaking accumulator, which you would have known if you bothered to read the Haynes manual diagnostic section or the Probst source that I cited in my how-to. Or God forbid, done a search here on the forum.

Good luck.

its a 7mm ID/2mm cross section

carried at advance auto parts, OR your local seal/oring supply.

I figured Id try the easy to get to $0.50 part first....
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Buwani 931  



Joined: 31 May 2004
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Location: Napa California

PostPosted: Fri Jan 31, 2014 5:27 am    Post subject: Reply with quote

There is a smaller one on the tip.
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