I know of the common leak sources, but this one I can’t find much info about.

Really just want to know, is this threaded in as far as it should be? The hose clamps are quite tight; I see no evidence of leaking from any other location than the line fitting at the rack.

Video, per usual:

 

That is caused by the double SAE flare having been over-compressed. If you undo the fitting - unless there is a piece of grit in the bottom of the hole - you will see the flare has been flattened. In the hole you will see an anular groove that flare fits into, try popping an O ring into it and refitting the flare nut. Do NOT do it up stupid tight, just enough; if it leaks still a touch, tighten a touch more. This may, repeat may, do the trick, it has worked for me in the past many times.
Failing that, a new pipe is the only option, or if enough room and pipe, cutting off the old flare remaking it - not forgetting to place the flare nut on the pipe first.

 

Thanks Greg, I’ll take it out and examine the flare. Are you saying that in the absence of a damaged flare, an o-ring is not necessary? I thought connectors like this always use an o-ring.

Can someone confirm which line this is? I thought the larger one was the return line, but based on this diagram the larger one on bottom is the feed line (#3 in this diagram): https://mossmotors.com/power-steerin...ulics-xjs-v-12

If I have to replace the line, must it be Jag specific, or has anyone had success using a generic line?

 

T he flare IS damaged, you need a O ring or a new pipe. The larger pipe is the return line, which carries very low pressure.

 

I understand, what I want to know is if I replace this with a new one, should I still use an o-ring?

 

No.

 

Thanks Greg - do you know if anyone has had luck using a generic PS line fitting? Not a matter of cost, but rather time; Moss Motors sells the return line but shipping from CA to TX takes a while.

 

As your low pressure return fitting is leaking, why not try the O ring?

 

I'll certainly give it a shot, though for $15-30, a brand new generic fitting would be a nice backup if this doesn't work.

Just to clarify: which of these two positions should I try an o-ring (1 goes around the line and would be compressed between the end of the threaded piece and the backside of the flange; 2 would simply go on the end of the flange and match its circumference)? This is a screen shot of the actual low pressure line from Moss Motors.

 

I wouldn't use an oring. There is no way to capture it and when tightened on it could come apart and clog your spool valve. You can try a copper washer properly sized with in a lathe. You can also anneal the steel flare to soften up so it can seal. This involves heating the flair end until they are red hot so you'll need to wrap the hose end in a rag soaked in cold water.

I wouldn't think the low pressure line is leaking, It more likely the high pressure side is leaking and running down and gathering on the cooler bottom 1/2 of the tack tower. Clean with brake clean, then a blast of air (can) and then setup an old cell phone to record a video while you star the engine to see where the leak originating from.

 

One thing that stands out to me in the video - it looks like the tube is at a pretty severe angle relative to the nut. How many turns did you thread the nut before you put a wrench on it?

 

I couldn't put a number on it; it takes forever to tighten those silly things due to limited space (at best I was making 1/4 turn at a time).

I noticed this as well but I couldn't find a way around it; I loosened the threaded piece just enough to allow some play and then rotated the steel line until it avoided running into the motor mount (V8 swap car, so don't know if space is an issue with this on the V12's). I would jiggle it around a little bit and it certainly felt to me like the line flare was mating properly with the rack flare; despite the angle in the picture, it certainly didn't feel like the flare was coming in at an angle.

I do wonder if instead of the o-ring suggestion, I try using a small neoprene washer in between the flares. I feel like perhaps the flat surface will be easier to "sandwich" between the two flares, as opposed to a tubular o-ring, which may slide out of position under pressure when I tighten everything down.

 

I think @icsamerica is on the right path here. I'd suggest some and a nice . Drop some dye in the reservoir, start it up, and you'll be able to see exactly where it's coming from.

I'd also suggest dropping the rack so you can clean it and see better.

My final suggestion is that you remove the hose ends from the pump/cooler, drop the rack, and put the lines on when the rack is hanging low. It's much easier to line-up and tighten the fittings when you have enough slack in the hoses.

 

Thread tape?

 

No, the threads don't form the seal. The flare on the tubing does. If the flare or the mating seat in the rack is damaged, the joint will leak.

 

I went ahead and tried the o-ring route, if just for kicks. I placed the o-rings between the backside of the flare and the end of the threaded piece. Did the same on both the feed and return lines.

So far, so good. Haven't had a chance to drive it, but started it up and turned wheel several times, adding fluid along the way till full.

Checked back an hour later, no fluid on the ground. Fingers crossed the test dive tomorrow yields the same results.

If it continues to leak, I may go drastic and try some sort of permatex gasket maker - nothing permanent, but something along the lines of their excellent water pump gasket sealant may do the job, and shouldn't prevent me from disconnecting the lines in the future. I of course wouldn't be putting the sealant anywhere near the end of the fitting, but wherever it's leaking at the top. Though when day comes to remove them, I'd have to drop the rack and clean it all up. We'll see. Hopefully it won't come to that.

 

Position 2. Though the O ring must be placed into the hole at the bottom of the groove you will see there.

 

Took it for a test drive today and made sure to turn the wheel full-lock in both directions a few times. No leaking that I can see.

Now that I think about it, I think positions 1 or 2 in the diagram I posted would work.

If the flare isn't seating properly, Position 1 can still prevent leakage. The fluid would "leak" out around the flare but only make it a fraction of a mm before encountering the o-ring.