Leaking Fuel Pressure Regulator - O Ring?

[ParkerRocker]

I have recently replaced my fuel pressure regulator with a part from the local you pull it. I actually pulled three, just in case. I know that this one is working because i have vaccum tested the engine while using it and it responds predicably.

my problem is the seal, i am leaking gas from the point where it connects to the lower intake manifold.

I reused the O ring from the defective FPR, it leaked.
I reused the O ring from the "new" FPR, it leaked.

Inoticed that only ONE of the FOUR FPRs that i have in my posession have a rubber washer/band behind the O ring. Is this necessary to prevent the leaking? the old FPR did not leak and it did not have this on it.

As far as I can tell, its leaking from the point where it seals with the nipple on the FPR, that is to say the center of the O ring is not tight enough against the FPR to prevent 35+PSI of fuel from getting by.

Can i use a slightly smaller (but tighter) ring? Can I stack a smaller ring behind the bigger one to prevent leaks? Is there a trick to sealing this? I have used nothing, engine oil, and saliva to lube the ring before inserting the FPR.

 

[boggs1227]

i wanna say that mine had that little washer behind the o-ring but not sure been a year ago ... so you did or did not use and lube for the ring ? i used 30w engine oil no silicone based oils were used .if you have problems sealing u may be able to use a injector o-ring i think they are the same diameter but when you go buy them at the suto parts store buy the "green" ones from what i was told " maybe a tuffer material or something to that effect.the one that came with my package ( fpr kit ...fpr and some o-rings in the box) sealed right off .

maybe that your fuel rail where the fpr conncets to is wollered out from to much removeing in it's past ...and the metal inside the fuel rail has become worn and sealing is not ever going to happen .

 

[fixxxer]

Always use a new o-ring on the FPR and you can use vaseline to lube.

 

[MrShorty]

If I've understood correctly, you've re-used the old o-rings. For something that sits in service as long as an FPR, it is unreasonable to expect that o-ring not to deform over time. IMO, the "trick" to getting that to seal is to use a new o-ring. When you buy a new FPR, it usually comes with an o-ring. Where you are trying used FPR's, I would suggest finding a source for new o-rings.

 

[ParkerRocker]

i forgot to mention that i bought a new O ring, that one also failed.
I just replaced it with a smaller and tighter one. It seems to be sealed tight. I have yet to drive it, i am letting the spilled gas fumegate and i have a paper to write. I will let you know the results. I did not lube this ring yet. What is the purpose of that?

 

[boggs1227]

lubeing the o-ring lets it properlly seat it's self inside the fuel rail ...failure to do so will make the ring maybe only seat and seal on one side and not so much on the other sides of the ring and then you gota leak .

if you did not lube it and installed it go buy another "new" one and lube it correctlly ,i would not really try to re-use the other rings at this point ...just start over fresh so to speak.

 

[fixxxer]

Not lubricating the o-ring can cause the rubber to "roll" out of place or get pinched or cut then you reassemble the FPR causing it to leak.

 

[MrShorty]

Be sure to check the sealing surfaces and make sure they are clean and that there are no left over bits from an old seal clinging. See if there are scratches/pits/other surface imprefections that might prevent the o-ring from sealing.

 

[ParkerRocker]

still leaking.
Vaseline? would that clog the injectors?

 

[fixxxer]

No, it's petroleum based and won't hurt anything

 

[ParkerRocker]

a new question

well i tried yet again to no avail.
Heres my next question, i have three FPR's that i pulled at the junkyard. I wish i had paid more attention to the years that the regulators came off of because there are two different types.

One has two ridges on the tit, one for the O ring, and one for a plastic washer, the other one has only ridge, what one is the most effective?

I will try Vaseline this time, for some reason my friend did not have any and this was performed at his house.

*EDIT* I read that smacking the FPR with a rubber mallet will help to seat the O ring, what do you think?

 

[sosbmx]

I have this same problem and no answer. It seems that this o ring is kind of flat on the outer diameter whereas any o ring I can find is completely rounded. Ford dealership said buy a new fpr and nowhere in this town has an o ring like that one... I have too much pride to pay 175$ for a fpr!!! My exploder only cost me 600$!

 

[JimbozX]

Fuel Pressure Regulator leaking

I have a leaking FPR where fuel spews out from under the FPR. From visual inspection, it looks as though the mounting surface is bent or concave, where as the screw hole surfaces are higher than the inlet surface?

Does this make sense or could the mount surface become warped or bent?

 

[BWTGUY]

Here is the Fuel Injector on the 1st Gen V6