Engine/Transmission (1998.5 - 2002) Help! Mech Fuel Press gauge leaks!

[Hohn]

Well, after negotiating the hard parts of getting the isolator plumbed in and such, I FINALLY was at the part where you get to fire up the engine and see if the gauge works.



I left it out of the pod initially so I could leak check it. It seeped from the threads of the fitting where the capillary tubing goes to the gauge (the tube is filled with antifreeze). No prob- took it apart, put some thread sealant on it and screwed it back down. No problem so far.



I decided to install it into the pod. With the engine off, I slid it into the pod and made sure the the wires went through the hole where I had already fed the capillary tubing through the back of the pod.



I fired it back up, and all was good, for a second-- the BAM!!, it starts leaking antifreeze so bad it filled the bottom of the mounting cup, and was leaking out the wire hole!!



I disassembled it again, pulled the tubing out, and put a little RTV on the outside of it. Then, a gently put it back into the tube fitting. I haven't put it back together yet, so I don't know if it will work.



My questions concerning the capillary tubing: How does the brass fitting seal? Is it a nipple and cutter setup? The brass fitting came with a plastic insert, and the insert seems to be a problem. When I first took the gauge out of the package, I thought it was a packing seal, so I tried to get it out. It was oviously meant to be there, I concluded. The other end (going into the isolator) had it too, and was already assembled. I damaged the outer ring of this plastic collar, but the innards are still inside the fitting. Could this be the cause of my leak?



I suppose the one good thing about this mess is that I have a solid 15PSI at idle.



Thanks for your help and patience.



HOHN

 

[illflem]

The plastic collar you speak of is called a ferrule and is your problem. Ferrules don't take well to over torqueing, distort then leak, you need to replace it. If you can't find a plastic one brass will do. Only tighten it finger tight then half turn with a wrench. The threads on this type of a sealing system don't make the seal, thread sealer won't help. The silicone you used may work short term but I wouldn't trust it for long.

 

[Hohn]

OK! So now where do i get a replacement ferrule from? I bought the gauge from Enterprise, and I am sure that they would have extras somewhere, but i would love to be able to find a local source for the part if at all possible. Napa? Home depot? Who might have this item?



Any ideas?



Thanks.



Hohn





BTW-- the gauge is very nice. it is 0-30psi, and is very legible (white face). It's also a great price from enterprise, cheaper than the Autometer.

 

[Bigsaint]

Local hardware store should have the brass ferrules.



Scott W.

 

[illflem]

1/8" ferrules are available at some hardware stores or Napa, you might have a hard time finding a plastic one but brass is fine. Every time I've needed one Napa just gives it to me rather than ring up 3¢. If you ever have to take this type of fitting apart it's a good idea to replace the ferrule to guarantee no leaks, this also means leave a little extra tubing as the only way to get the old ferrule off is to cut the tubing.

 

[Hohn]

Just spoke with Enterprise..

Doug told me that the fitting on the back of my gauge is METRIC.



He also said that the damage I did to the collar shouldn't have affected anything.



I bought the 1/8" ferrules, and I am going to give them a try, but they look a wee bit small.



Anyway, Doug is sending me a new fitting, maybe that will fix it.





The only thing all my problems have in common is their cause-- ME!





HOHN

 

[HOSS]

Hohn,

Look in the 2nd generation ram forum at the thread titled "Di-procol fuel pressure gauge malfunction"

you may get some answers there.

Hoss

 

[Hohn]

doing it right...

Thanks for the info, fellas.



I decided to do it properly, and I am running -4AN stainless from the isolator to the gauge. The back of the gauge is 1/8NPT so why screw around? Rather than screw with a mystery fitting that may or may NOT leak, I am going to spend the money, run REAL hose to that thing.



the -4AN is probably double the thickness of the plastic tubing, so hopefully my existing routing will still work. Shouldn't take too long to fab up the line, fill it with antifreeze and hook it all up.



I'll let you know how it goes when I get it all together.



HOHN

 

[CFAR]

Just buy a longer hose and go straight to the guage, I've got a $100. 00 autometer isolator I don't use, didn't work right because I had my gauge so far above the isolator should be as close to level as possible.

 

[illflem]

Second that, can the isolator.

 

[Hohn]

That may be true of the Autometer system, but the Enterprise system seems to read very well. When it was (briefly) connected, it showed a solid 15PSI. If the isolator needed to be at the same height, it would low, not high, and I am guessing I don't have much more than 15PSI with he stock lift pump.



hohn

 

[Camara]

It is a good idea to replace that ferule every time you have it apart. I mounted my guages under the ash tray. Mine was leaking, so I gave it another 1/2 turn. All was OK until it got cold. I guess I crushed it too much and one night it broke. Now I have to put in a new carpet!:{

 

[illflem]

If you would have had a needle valve installed close to the engine and cranked almost all the way shut the leak would have been very minimal even over several hours time. You also would have been able to shut it down and still use the truck without dieseling your cab. $3 valve goes a long way for insurance.