FPR o-ring

[mattw]

Can anyone explain to me why this continues to happen:

I'm using a stock sy/ty fuel return line that I convert over to rubber then connect back to the stock return line under the drivers door. I've replaced this o-ring multiple times and it keeps going bad and leaking.. I thought maybe the movement of the engine was too much for the fitting so I made a bracket that attaches to the back of the head and stabilizes the metal line.. The o-ring continues to fail. I have been installing these very carefully and I do put a bit of oil on them during install. These are the o-rings that I have been using:

Any ideas? I'm about to order a 14mm o-ring to AN adapter and just do braided line back. My only concern is that I may not have enough room under the FPR for the adapter then a 90 degree AN fitting. It may come into contact with the intake manifold or the valve cover..

If you have any idea why this is happening please let me know..

 

[Z SKI]

Re: FPR o-ring

Hey Matt,

Maybe a little burr on the inside of the AFPR or o-ring matting surface on the fuel line?? I'm sure you are putting a little bit of oil on the o-ring during installation.. edit... just saw that you are oiling them.... Maybe just junk overseas o-rings???

See ya,

 

[mattw]

Re: FPR o-ring

Hey Matt,

Maybe a little burr on the inside of the AFPR or o-ring matting surface on the fuel line?? I'm sure you are putting a little bit of oil on the o-ring during installation..

See ya,

Yeah, I should have noted above that I checked for that as well.. Both surfaces are nice and flat/smooth..

 

[gringo76]

Re: FPR o-ring

Lube that sucker with axle grease. When I do an fittings and hose if you use the wrong lube it will rip the line every time . For some reason the universal axle grease I use works.

 

[Don W.]

Re: FPR o-ring

Can anyone explain to me why this continues to happen:



I'm using a stock sy/ty fuel return line that I convert over to rubber then connect back to the stock return line under the drivers door. I've replaced this o-ring multiple times and it keeps going bad and leaking.. I thought maybe the movement of the engine was too much for the fitting so I made a bracket that attaches to the back of the head and stabilizes the metal line.. The o-ring continues to fail. I have been installing these very carefully and I do put a bit of oil on them during install. These are the o-rings that I have been using:


Any ideas? I'm about to order a 14mm o-ring to AN adapter and just do braided line back. My only concern is that I may not have enough room under the FPR for the adapter then a 90 degree AN fitting. It may come into contact with the intake manifold or the valve cover..

If you have any idea why this is happening please let me know..

I believe this takes the same o-ring as the injectors. Is that the one you're using? It almost looks like the o-ring is coming up against something before it gets to where it's supposed to be. The picture isn't clear enough but see where the o-ring has a grove or is distorted on its inside diameter where the cut is? That shouldn't be there. The o-ring shouldn't be damaged that way. (Duh) That's an aftermarket FPR. Maybe it wasn't machined properly? Do you have another? Or the stock one to compare?

I think you're correct. Not enough room to adapt an AN fitting. If you could even find one that fits. The threads in the FPR are -not- pipe threads. IMHO Attempting to screw something different then what's supposed to be there is still gonna leak.

 

[mattw]

Re: FPR o-ring

I believe this takes the same o-ring as the injectors. Is that the one you're using? It almost looks like the o-ring is coming up against something before it gets to where it's supposed to be. The picture isn't clear enough but see where the o-ring has a grove or is distorted on its inside diameter where the cut is? That shouldn't be there. The o-ring shouldn't be damaged that way. (Duh) That's an aftermarket FPR. Maybe it wasn't machined properly? Do you have another? Or the stock one to compare?

I think you're correct. Not enough room to adapt an AN fitting. If you could even find one that fits. The threads in the FPR are -not- pipe threads. IMHO Attempting to screw something different then what's supposed to be there is still gonna leak.

It does use a fuel line o-ring where it presses into the rail. That part is sealing up fine.. This is the o-ring that goes in the bottom. It's 5/16" and the same as the rest of the o-rings used for the fuel return line.

I did notice the cut in the o-ring. I tried to get a clearer picture but I was not successful. I'd take another but I think I left that bad o-ring at NAPA.. It is an aftermarket FPR. I think I bought it from TurboTime a LONG time ago. It's the same one that TurboTweak and SportMachines sell today. I do not have a stock one to try or to compare to. I have looked closely at the inside of the FPR fitting and it seems smooth and proper..

Those threads in there are 14mm x 1.5 with an o-ring connection. They make adapters to convert that to AN.

 

[Don W.]

Re: FPR o-ring

It does use a fuel line o-ring where it presses into the rail. That part is sealing up fine.. This is the o-ring that goes in the bottom. It's 5/16" and the same as the rest of the o-rings used for the fuel return line.

I did notice the cut in the o-ring. I tried to get a clearer picture but I was not successful. I'd take another but I think I left that bad o-ring at NAPA.. It is an aftermarket FPR. I think I bought it from TurboTime a LONG time ago. It's the same one that TurboTweak and SportMachines sell today. I do not have a stock one to try or to compare to. I have looked closely at the inside of the FPR fitting and it seems smooth and proper..

Those threads in there are 14mm x 1.5 with an o-ring connection. They make adapters to convert that to AN.

No prob with the thread size. I just didn't want you to think you could put a pipe fitting in there. You'd be surprised what people try to screw together and then wonder why it leaks...:rotf:

You're correct on the o-ring. But something is cutting it. Unless you're severely over-tightening it which I doubt. Also why the grove on the ID? weird.

You say you've had this FPR for a long time. Yet this leak is new?

 

[mattw]

Re: FPR o-ring

You say you've had this FPR for a long time. Yet this leak is new?

No, I've been smelling fuel for a while. Even had a fuel smell when I used this regulator on my old Ty. Now that I've found this I suspect it was the culprit all along. So I just recently replaced the o-ring and it started leaking again. Took it apart and it was shredded. So I put a new o-ring back in, made a bracket to hold the line in place, put it back together and it started leaking again.

I think I'm going to try one of these with a crush washer:

Then one of these to take it to -6 AN:

Going that route will eliminate that o-ring and rely on the crush washer to complete the seal. That way even if the AFPR does have an issue where the o-ring seals it will no longer present a problem..

If your not familiar with my truck this probably seems like it doesn't make any sense. Fact is my engine setup has very little in common with a sy/ty other than this regulator and that return fuel line. Going to AN lines will be far superior to what I have in place now and using stock sy/ty stuff isn't an option.

 

[Don W.]

Re: FPR o-ring

Suite yourself. With all due respect a crush washer or some other system is a band-aid. Something is wrong with that FPR. That is the low pressure side. It just should not leak.

 

[Ty1642]

Re: FPR o-ring

I just ran a braided return line from my FPR, using this adapter from Racetronix and an Aeroquip 90 degree fitting. The Racetronix adapter is machined down to make it slightly shorter, and comes with an O-ring washer to seal it against the bottom of the FPR. The whole assembly cleared the top of the intake manifold. I was a little concerned about how well the O-ring would seal, but it works fine. Racetronix also sells a similar adapter sized for the feed line to the fuel rail.

http://racetronix.biz/itemdesc.asp?ic=392-460614BLM&eq=&Tp=

 

[mattw]

Re: FPR o-ring

I just ran a braided return line from my FPR, using this adapter from Racetronix and an Aeroquip 90 degree fitting. The Racetronix adapter is machined down to make it slightly shorter, and comes with an O-ring washer to seal it against the bottom of the FPR. The whole assembly cleared the top of the intake manifold. I was a little concerned about how well the O-ring would seal, but it works fine. Racetronix also sells a similar adapter sized for the feed line to the fuel rail.

http://racetronix.biz/itemdesc.asp?ic=392-460614BLM&eq=&Tp=

Thank you!! That's a great price considering he is turning that fitting down and providing the o-ring washer!

 

[mattw]

Re: FPR o-ring

Suite yourself. With all due respect a crush washer or some other system is a band-aid. Something is wrong with that FPR. That is the low pressure side. It just should not leak.

I agree with you & appreciate your feedback but I see no reason to buy a whole new FPR just because its tearing up o-rings. I placed my order earlier today and I got one of these as well:

I'm going to try to use that first but if there isn't enough room, or this o-ring gets torn up as well, I'll use the tighter fitting part with the crush washer..

 

[wildphil]

Re: FPR o-ring

It hasn't been to many years ago that I bought factory fuel line o-rings. They look to me like they have some sort of fiber in them and are stronger than the rubber ones. They may work better.

 

[Quickstop [UK]]

Re: FPR o-ring

It looks like the o-ring you are using may actually be too small. It looks like it fits snug around the pipe then when it gets compressed, part of it gets a bite taken out by the AFPR and the rest of the o-ring is pushed outwards. A slightly larger diameter may prevent it from being bitten in the first place.

I have an AFPR with an AN adaptor. It goes to a bmrubber fuel hose (-6) and whilst tight, it fits.

 

[mattw]

Re: FPR o-ring

My parts came in last week and I got everything setup. I tried the o-ring adapter first but I just didn't care for it.. It felt like I was going to crush the o-ring if I put it as tight as it needed to be(so that it would not loosen with engine vibration).

I decided NOT to go that route. Instead I opted to use the crush washer adapter:

I think that my issue is resolved now. I'll know for sure when I bring it home and park it in my 1-car garage. If I don't smell fuel then its fixed...

 

[Don W.]

Re: FPR o-ring

FWIW it looks good and I hope it works for you. Interesting injector manifold. The FPR is on the "wrong" side. If you don't mind how does the pressure line connect?

 

[mattw]

Re: FPR o-ring

FWIW it looks good and I hope it works for you. Interesting injector manifold. The FPR is on the "wrong" side. If you don't mind how does the pressure line connect?

Thanks.. I'll snap some pics today.. The other side is -8AN to a 3/8" NPT adapter that threads into the back of the rail.. The intake manifold is a RamJet. I bought the stock and made those fuel rails myself..

 

[Ty1642]

Re: FPR o-ring

The washer that comes with the Racetronix adapter I linked to is a combination of metal & rubber. The metal part prevents the washer from being overtightened, and the rubber part provides the seal. (Kind of like some GM transmission pan & similar gaskets.)

 

[mattw]

Re: FPR o-ring

If you don't mind how does the pressure line connect?

Here is a pic of the pressure side.. The black line is a braided steel line its just covered in black hose so that it wouldn't rub on anything...