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Fuel Pump set up

 
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agfisher  



Joined: 09 May 2007
Posts: 446
Location: West Hartford, CT

PostPosted: Thu May 02, 2019 2:01 am    Post subject: Fuel Pump set up Reply with quote

I am replacing my fuel pump and rebuilding all the fuel lines in the back. While I'm rebuilding I want to replace the copper washers used around the check valve and the banjo bolt. Looking in the P.E.T. I can't seem to find my configuration.



If you look at the picture above it looks like it details two different pump configurations. My configuration is different and has the pump output coming out of the end of the pump but uses the configuration with the end nut (P/N 6) that has the output coming out the side. The two listed configurations use different sized copper washers (one is 12x15.5x2.5 and the other is 10x13x1) so I'm trying to figure out which one I'm supposed to use.

So here are my questions:
1) I'm assuming all the cooper "crush" washers should be replaced?
2) If they are how do I know what washers to use? The old ones I have are a little warped so their original size is tough to figure out. Does it really matter, should I just find the closest size I can? Below is a picture of the check valve assembly that screws into the pump. Note that one of the copper washers goes all the way to the right on the part that screws into the pump.


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peterld  



Joined: 10 Dec 2006
Posts: 767
Location: Noosa Heads QLD Australia

PostPosted: Thu May 02, 2019 6:48 pm    Post subject: Reply with quote

Easiest move is to buy a box (kit) of Metric copper washers from a reputable seller and then size as close a fit to the relevant banjo/nut etc.
To be sure /to be sure: lap the washers (both sides) with 2000 grit wet/dry over a piece of glass or something perfectly flat ( I use a heavy piece of aluminium plate)
Many of your old washers may well be savable using the lapping method.
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TJC  



Joined: 04 Apr 2010
Posts: 739
Location: Central-ish Arizona, USA

PostPosted: Fri May 03, 2019 1:34 am    Post subject: Reply with quote

peterld wrote:
Easiest move is to buy a box (kit) of Metric copper washers from a reputable seller and then size as close a fit to the relevant banjo/nut etc.
To be sure /to be sure: lap the washers (both sides) with 2000 grit wet/dry over a piece of glass or something perfectly flat ( I use a heavy piece of aluminium plate)
Many of your old washers may well be savable using the lapping method.


This^
Or you can measure the OD, ID and thickness of the washers you have and order them from places like Autohaus Az., Pelican and others who sell them separately if you need additional Porsche bits or even source them at a local industrial supply house.
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agfisher  



Joined: 09 May 2007
Posts: 446
Location: West Hartford, CT

PostPosted: Fri May 03, 2019 2:23 am    Post subject: Reply with quote

If the ID is the same as what is spec'd how important is the OD and thickness? Can I use a washer with a thickness of 1.0mm instead of 1.5mm? One of the parts is spec'd at 2.5 but measured at 1.73mm.
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MikeJinCO  



Joined: 08 Jun 2010
Posts: 863
Location: Maysville, Colorado

PostPosted: Fri May 03, 2019 5:34 am    Post subject: Reply with quote

Copper work hardens so you can anneal them for reuse by heating to a dull red and letting them cool. Then clean them as Peterld described. Thickness shouldn't be too important. Pegasus Racing has new ones also
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TJC  



Joined: 04 Apr 2010
Posts: 739
Location: Central-ish Arizona, USA

PostPosted: Sat May 04, 2019 2:29 am    Post subject: Reply with quote

Annealing works wonders for copper although one must be diligent on a piece like this so as not to distort it.
As far as thickness is concerned I would hesitate to go thinner as you want to be sure you have enough "crush" for the application dependent on the shoulder of the banjo bolt to thread distance. If the washers aren't thick enough the bolt may bottom out before making a proper seal. Consider your own measurement and why they call them "crush" washers!!!
Quite frankly these pieces cost very little and I can't see the reusing, lapping, annealing exercise to be worth the effort unless you're stranded out in Bumf**k, Iowa or some other godforsaken place.
Having said that I find myself scratching my head and wondering why this discussion, which I've helped prolong , has gone this far. Buy some new bloody washers dude and be done with it !!! The last thing you want is a damn fuel leak, right?

Sheesh, I think I'm done here...I've said my peace .
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agfisher  



Joined: 09 May 2007
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Location: West Hartford, CT

PostPosted: Sat May 04, 2019 10:58 am    Post subject: Reply with quote

I was really never planning on reusing the old crush washers and was just confirming that. The problem I was running into was i was having a hard time finding what size the original washers were to find replacements. I ended up getting an assortment focusing on the ID and thickness in the selection.

Thanks for all the great advice!
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