Rochester Inlet Leak Quad

Hi-

At least I think it's the inlet. Trying to work thru using new washers etc and having no luck. Right below the inlet nut is a piece that protrudes out about and inch or so, maybe finger size diameter, appears to be some kind of plastic. Does anyone know what it is? It doesn't show up on the parts breakdown. I marked it on the photo with a black line. Engine is an '86 V-6. (sorry for the pic size, I tried to shrink it down) Could whatever this is be leaking? It's really hard to tell where the exact origin is. I'm betting the inlet nut and dripping down on this thing but since I don't know what it is, it's suspect too. Thanks, Rich

your mystery fitting is likely a vacuum port for a PCV hose...most i have touched are metal but they will have a rubber/plastic cap over it...

i guess your leak is fuel??

as far as the origin, a thin strip of paper towel or the plastic shop towels strategically placed can help locate the origin...

Did the leak start after work was done ? does the fitting on the line start into the inlet easily, using your fingers?

makomark said:

your mystery fitting is likely a vacuum port for a PCV hose...most i have touched are metal but they will have a rubber/plastic cap over it...

i guess your leak is fuel??

as far as the origin, a thin strip of paper towel or the plastic shop towels strategically placed can help locate the origin...

Did the leak start after work was done ? does the fitting on the line start into the inlet easily, using your fingers?

Click to expand...

HI Mark,

Thanks. And hope I'm not too wordy. The leak started of course on launch day. I had started and run the engine probably half a dozen times while I was getting ready and the leak just appeared. Yes, gasoline. When I disconnected the line I noticed the gasket/washer 7/8" dia alum with rubber on each side was a bit beat up. I got the correct size nylon washers that are a bit thicker, put a new washer that goes on the open end of the filter, and put a new filter in, (spring is fine). Still leaked. Now I'm convinced it's leaking on the 5/8" fuel line end, so I ordered and installed a new fuel line (fuel pump to carb) and it leaked. The threads seem good on the 7/8, they look clean and don't feel like they have stripped at all. Anyway, I ordered a new inlet nut and waiting for that to arrive. Frustrating because there's only 2 places it can leak. I will try your paper towel trick to see. The 5/8" fitting starts pretty easy into the inlet nut, I have to keep pressure on the fuel line when I thread it but can get it threaded 1/3 to 1/2 way before I have to use the wrench. Do you think I could try 2 nylon washers? Or a washer sandwich with the original aluminum style? --Rich

i believe you need to figure out what is leaking first...

if you have a new fuel line and it leaks, it could still be around the nut or the flare on the nut is not seating...or the housing where the nut threads in could be cracked...

i trust you use a 1" wrench to hold the nut and a GOOD flare nut wrench on the line's nut?

finally, when it comes to leaks like this, gravity is your friend, so it will pull the fuel 'down' from wherever it is escaping from..

Thanks Mark. Yes, 1" wrench and a real flare nut wrench. I'll report back after I try the new nut. Have a good day. --Rich

I went through a full carb rebuild this year and had a similar leak after taking the fuel line and flair nut off and on so many times. I used a little putty on the threads and that worked just fine. Just don't put too much on as it can build up and be careful not to let any loose bits fall into the carb inlet once you put it together. As far as that inlet you originally asked about, Mark was right it is for a PCV connection and the boot that goes over it keeps it from vacuum leaking. You should have a flat metal washer on the 7/8 nut to the carb (one inside as well by the filter) but the fuel line fitting can leak even though it seems tight on that larger nut.

junior4597 said:

I went through a full carb rebuild this year and had a similar leak after taking the fuel line and flair nut off and on so many times. I used a little putty on the threads and that worked just fine. Just don't put too much on as it can build up and be careful not to let any loose bits fall into the carb inlet once you put it together. As far as that inlet you originally asked about, Mark was right it is for a PCV connection and the boot that goes over it keeps it from vacuum leaking. You should have a flat metal washer on the 7/8 nut to the carb (one inside as well by the filter) but the fuel line fitting can leak even though it seems tight on that larger nut.

Click to expand...

Thanks Junior. Was your leak at the fuel line connection and not where the 7/8 threads in? And as for "putty?, what exactly did you use and on what threads? I have a new nut coming, so will see what happens when I put that on.

make sure you check the face of the flared steel line before you put it back together...same for the matching face on the 'large nut'...

Will do!

Yes, the fuel line connection but if you are getting a new line and flair nut then that might help your situation. I'd use a little putty as well, don't use any tape though. Regular plumbers putty will do fine, just don't goop it up and make sure you don't get any on the flair tip of the fitting as to prevent it from seating correctly. How are you getting the new flair nut on? Are you getting a new fuel line coming from the pump or do you have a flairing tool to re-flair the line once you slide the fitting on? Either way new fittings and some putty should help your situation if in fact it's leaking in that area.

Good luck!

So installed new inlet nut (brass) & components. Fuel line into nut is new. Back together and very slight drip where the inlet nut screws into carb. The nut kit came with a rubber coated alum washer, same as was removed. I have the thicker nylon ones, too and I think I'll swap that out and retry. I cranked it down pretty good when I put it on but don't want to do too much. My Crusader manual says 18# on both the carb nut and the fuel line nut. Seems like a lot.

18 ft * lbs is pretty snug for the larger nut....I'd suspect either side of the gasket surface for the fuel inlet nut - and make sure the body of the carb (where the fuel inlet nut threads are) isn't cracked...you shouldn't need any 'putty' to make leak free connections....that said low strength lock-tite and PST have been used successfully on those 'bastard connections'...

Hi Mark & Junior. Three successive runs with no leak. Thanks for your help and also identifying the pcv part. Happy Boating!

so, would you say the nylon washer resolved the drip?

Well I'm not sure. I originally put together with the new nut and the coated alum washer and it did not leak at 5/8" connection but did at the big 7/8 washer. I switched it out and put on the nylon one, then it leaked at the 5/8". Took apart again and tried the plumbers putty (I think 99% of it squeezed out when I slid the small nut on to the fuel line end) I cleaned it off and reinstalled and not leak. You are right about those bastard connections. And it's really hard to know how much to tighten up those fittings.