fuel pressure regulator o ring leaking..

[The Darkside]

I had the fuel regulator off recently due to replacing the head gasket & I noticed it leaking today... I took it off & it the o ring between the regulator & the fuel rail was damaged....I guess I must have pinched it when I put it back together. Anyways, I went to the auto parts store & bought a Felpro o ring kit that's designed for our fuel injectors(supposedly the same size as the regulator o rings)... Before installing it I put some Vasoline on the o ring & slowly & evenly tightened it up... It leaked even worse!!! I took it off & reinstalled it 3 more times & each tme it still dripped. Went back & bought a o ring kit that had several different sizes in it from the auto parts Help section... Installed one of those that looked like a perfect replacement & although it's not dripping now , it is still slightly seeping gas... Do I need to go get a GM o ring or what? I did notice that whenever I took the regulator off when replacing the head gasket that it came off kinda hard & felt like it was popped into place.... It doesn't feel that way when I put it on or take it off now.... Any suggestions?


The Darkside

 

[turbofrank]

O-ring should fit tight thats why vasoline is used. Fpr o-ring is also used on fuel injs . Make sure there is no trash or debri in fuel rail opening.

 

[The Darkside]

Thanks, I'll double check it...maybe a piece of the old o ring where it got damaged is still in there.....By the way, are you the Frank that ports & polishes heads? I know I bought a set back in 2003 or so & they're still on the car...

The Darkside

 

[salvageV6]

If it's a really really old regulator they used to use a phenolic or hard type spacer on them to push against the O ring that also was able to come off and get lost.

I think the early Kenne Bell ones and Accufab ones used it.

If it fits loose there may have been a spacer in there that's missing.

 

[turbofrank]

nope

 

[The Darkside]

Well, double checked for anything that might be keeping it from sealing up & found nothing...It's clean. The regulator does have a small plastic spacer on it, but even with the o ring on there it's still a tiny bit loose....Is it supposed to be??

Went & bought a few more o rings from AutoZone & tried them, but still leaking!!! This should be a super simple deal, but it's turned into a real pain... Ugh!!!

I mean what else could it be????

Anyone got a factory o ring laying around off of an injector??? This is driving me crazy...

 

[QUIP'6']

Well, double checked for anything that might be keeping it from sealing up & found nothing...It's clean. The regulator does have a small plastic spacer on it, but even with the o ring on there it's still a tiny bit loose....Is it supposed to be??

Went & bought a few more o rings from AutoZone & tried them, but still leaking!!! This should be a super simple deal, but it's turned into a real pain... Ugh!!!

I mean what else could it be????

Anyone got a factory o ring laying around off of an injector??? This is driving me crazy...

mine was leaking and i thought it was the small o rings and replaced them and still leaked and here it was the rail o ring which is the same as an injector o ring. advance auto has them cheap in a set just a few bucks

 

[The Darkside]

I've tried multiple o ring's..... Felpro, Oreilly's Auto Parts & from AutoZone & every one of them leaked.... All together I've probably taken the FP regultor off & back on again about 20 times & tried vaseline, white grease & Tranny fluid to lube it.... Tried tightening it up very slowly & evenly, tried not to tighten it too much & tight enough that I twisted a bolt in half....lol, nothing has worked so far(but now I have 2 new bolts)...

 

[mearly65]

How are you installing it? Mine leaked when it tightened the fuel line before the two regulator bolts. It drove me nuts. So l took it back off, tightened the two bolts first and then snugged up the fuel line. No leaks after that.

 

[The Darkside]

I'm connecting the fuel line first(hand tight) then the 2 bolts which I tighten completely, then back to tighten the fuel line up(which is really already very tight from hand tightning it) This is really insane, this should be a quick & easy 5 minute job....

 

[turbofabricator]

Might be a scrarched fuel rail boss or pressure regulator o ring seat. Or the fuel rail is cracked where the regulator plugs into. Try another regulator to see if that is your problem. Try the stock one. Are you sure its the o ring and not the diaphram leaking?

 

[mearly65]

I think hand tightening the fuel line might be making it too tight. Try just starting it a few threads so its still very loose and then finish it up with the wrench. Also, are you using a black or brown o-ring? Some black o-rings are not rated for contact with gasoline. Just a thought.

 

[The Darkside]

I don't have another regulator to test with, but I will take a very close look at the rail for cracks...I don't see any leakage from seam where the top 1/2 of the regulator & botton 1/2 go together, but I will also double check that this afternoon too...

I went to NAPA & got another brand of o ring that is made for the injectors on our GN's, so will give it a try....

 

[The Darkside]

Great news..... The o ring I bought from NAPA worked perfectly!!! I noticed when comparing it side by side with the other brands I've tried that it looked to the naked eye to be slightly larger in both diameter & in thickness....Anyways, thanks to all who offered their opinions & helpful suggestions, I really do appreciate it....

The Darkside

 

[LEGACY_GN]

Having the same issue. 2 different o rings leaked from Oreilly. Felpro and a generic. Just called napa, going to try that.

 

[dynoman]

If you guy's can get me the dimensions of the O-ring , I'll match it up to a factory original ( they come in bags of 1000 pcs. ). We still make the non-adjustable fuel pressure regulator from back in the day and have all the OEM O-rings because we are the OEM ! Sam