Fuel Leak Rail Sensor

FST_DSL · Nov 1, 2009

This is an ongoing problem.

I noticed a small fuel leak a few weeks ago and traced it to the Rail Sensor i loosened it applied some teflon paste and tightened it back in!

the leak stopped but it has come back and i have removed the sensor and replaced it with and without paste but it still leaks!

it doent leak at idle but anything over 10k it sprays alot of fuel.

is this a common problem? is the high pressure causing it? is there suppose to be an oring or anything on it?

FST_DSL · Nov 1, 2009

thank in advance guys im goin to try again but Im scared to get it in there too tight!~

triton · Nov 1, 2009

it is suppose to have a 0 ring in it. 10K psi + is a lot of psi. Teflon isn't gonna get it.

THE STIG · Nov 2, 2009

triton said:
it is suppose to have a 0 ring in it. 10K psi + is a lot of psi. Teflon isn't gonna get it.

I beg to differ, I thread tape 1/2'' npt fittings at work and p-test to 15k often.. no leaks even with a 20k gauge screwed in hand tight.. thread tape does work just make sure your wrapping it the right way when you screw your fitting in.. if you wrap it backwards and your screwing clockwise the tape will come off

Volcom18 · Nov 1, 2009

Bump... is there something he could put on the threads?

FST_DSL · Nov 1, 2009

Mine doesnt have an Oring!

ruidosododge · Nov 2, 2009

Need to get a 0 ring back in there... And you did say your positive its the sensor?

smoke machine · Nov 2, 2009

jb weld??????? man cody was telling me about this. maybe try putting a new one in with a oring

easymon · Nov 2, 2009

you sure the rail its self dont have a hair line crack? Being that both leaked this would be my gess.

Big Horn Alberta · Nov 2, 2009

I dont see any pressure box in your sig. What is your rail pressure?
If you have a gauge just cap it that should take care of your problem.

Volcom18 · Nov 2, 2009

Haha, I told him to put jb weld aslo!

I don't think there's a crack, I've watched it as he revs it up and I can see the fuel spraying out where the sensor screws in.

As for pressure, he has a tst pda. Capping it might be the best bet, unless he just needs a darn o-ring.

FST_DSL · Nov 2, 2009

I cant cap it! :buttkick:

its not the relief its the pressure sensor!!!!

FST_DSL · Nov 2, 2009

oh and as for pressure Im running a BD and TST with added rp! RP is 17 crusing and 26-27 at WOT

FST_DSL · Nov 2, 2009

yeah its the Rail sensor! Im goin to try and get an Oring and see if that fixes it!

it didnt have an Oring the first time I took it off! It doesnt look like it had one either but Ill try anything

TCDiesel · Nov 2, 2009

The O-Ring may stop it.. Also we have the correct 1 for it, This is not a modded Rail from T&C bought from West Texas Diesel.. if it is it is cover under the Lifetime warranty and would be replace By US at no Charge. I will send you the O-ring. PM Address or email it to todd@tcdiesel.com

TCDiesel · Nov 2, 2009

NO.. Do TQ more than 85lbs MAX it should seat.The surface area below the sensor is the weakest area on the Rail and will crack.

TCDiesel · Nov 2, 2009

If you TQ it more than 85 ft lbs,it will be a 1 time shot, the seating area will get deformed,the next time you remove the sensor it will leak at some point.

Volcom18 · Nov 2, 2009

That's what I was afraid of after seeing your post. He's been looking into modded rails, so maybe now's the time to get one.

Shibbyutman · Nov 2, 2009

Gotcha, is it a face seal (Parker ORFS like) or boss o-ring like at the base of the threads?

TCDiesel · Nov 2, 2009

The O-rings we have are stamp by us ,When I found the correct part # Cummins wanted $2.00 per O-ring,No thanks, So we stamp our own at .05 each.

FST_DSL · Nov 2, 2009

Ok well im heading to the Dodge house Ill see if they have an Oring! I may see if he has a new sensor I can try in case mine has a crack!

is the sensor nut suppose to sit flush with the rail like the relief if it is mine still has some cranking to go!

And Twest no I do not have a modded rail I want to get a T&C wild rail like what cody is running I just havent got the funds yet! but I would like to see if its the sensor or the rail cause if it is the sensor they are around 240bucks for a new one!

Thanks for all the replys guys

also if it does need an Oring would it go on the inside or above the threads near the nut of the sensor?

FST_DSL · Nov 2, 2009

the Diesel Tech at Dodge says its not suppose to have an Oring! He says an Oring wont hold back 28k! but im not convinced I wanna believe there is a simple fix when the solution is probally a rail or sensor! but which is it? both will no doubt strain the pocket book!

TCDiesel · Nov 2, 2009

He's wrong We have been installing the O-rings for over 5 years,Send your address to us I will mail you the correct O-ring.Also I have a test sensor, You are welcome to use it I just need your promise to return it.Otherwise I will have to come to Texas and ********.

Shibbyutman · Nov 2, 2009

Check out the seat in the rail, that machined area should be flat all the way across and pretty much free of any witness marks. See if you can swap sensors into a buddies truck or something to see if the leak follows the sensor or if it seals in another truck.

FST_DSL · Nov 2, 2009

LOL thanks I just put in my roomates sensor and it didnt leak i ran it up to 27k and nothing and it was just a hair over snug (official trq specs)! guess ill be buying a new sensor it looks like genos is the chepest unless anyone knows a better place!

Damn and I had the money saved up for diff covers there it goes!

FST_DSL · Nov 2, 2009

Sensor on its way!

big thanks to Todd for answering my questions and helping me get a sensor without breaking the bank!

copenglenn · Nov 3, 2009

When my RPS went bad I picked up a new one from Rochester fuel injection, just happened to google them. Picked one up for a little over a bill. Glad you got it all taken care of.

schooner987 · Jan 10, 2023

How was the issue resolved?

Fuel Leak Rail Sensor

Top Contributors this Month

Recommended Communities