HD8 Banjos Leaking

[Goldie]

I have finally gotten around to tuning and getting my 1967 BJ8 going again after a basic HD8 carb rebuild. After a little tuning and messing with idle and mixture, I discovered a slight gas leak at both fuel bowls at the bottom of the banjo fittings feeding the fuel bowls. It is essentially an identical problem on both carbs. I have tightened with care and actually replaced the large bolts with new parts from Moss. I installed new fiber washers - I did not soak them as some have suggested. iIam doing that on a couple of new washers I had in my stash. Will install those after things cool off.

This is a slight seep more than a leak, but needs to be shut off. It is interesting that it is the identical problem on both carbs. I have questions for those with more experience. Also the new shut-off valves seem to be working correctly.

1) I adjusted the float levers to the specified clearance. Could that affect the seal around the banjo washers?

2) Is there any sealant that can be used on the threads or on the fiber washers that can enhance the seal? I am wary of using a sealant of any type.

3) Can a different style crush washer be used, i.e. copper?

Note: I replaced both brass floats with that new style that supposedly will not fill up with gas. I set the shut off arms at 7/16th.

 

[Editor_Reid]

So in other words, you have a case of drooling banjos?

Don't get up, I'll see myself out.

 

[roscoe]

Best pun I've read on this site. Have you been saving that for years? Are you here all week.....?

 

[AN6-TX]

HaHa! Drooling banjos aside, do you still have the "old" parts? Since its happening to both carbs, with the same new fittings, one can only assume its a replacement parts issue. I have no solutions - sorry - but intend to follow this to understand your solution. Good luck!

 

[Bob_Spidell]

I'm 'goop happy,' but avoid sealants in this area. The fiber washers should do the job; they do take a set and usually the banjo bolts need to be re-torqued after a few hours (try this first). The washers used to be a red-brown color, but most I've purchased in the last decade have been black, and seem to be a somewhat different fiber. I didn't measure them, but IIRC the black ones were a little thinner on the ring cross-section; less 'meat' could cause less sealing. Like a lot of after market parts, quality is suspect. The most recent large fiber washers, similar to the banjo washers, used on the O/D drain brass plug are a bit thinner than they used to be, and I'm having a problem getting a good seal with them.

 

[Michael Oritt]

Try soaking the fiber washers in a light oil for an hour or so before assembly.

 

[Goldie]

Try soaking the fiber washers in a light oil for an hour or so before assembly.

Doing that now in Marvel Mystery oil.

 

[Goldie]

I'm 'goop happy,' but avoid sealants in this area. The fiber washers should do the job; they do take a set and usually the banjo bolts need to be re-torqued after a few hours (try this first). The washers used to be a red-brown color, but most I've purchased in the last decade have been black, and seem to be a somewhat different fiber. I didn't measure them, but IIRC the black ones were a little thinner on the ring cross-section; less 'meat' could cause less sealing. Like a lot of after market parts, quality is suspect. The most recent large fiber washers, similar to the banjo washers, used on the O/D drain brass plug are a bit thinner than they used to be, and I'm having a problem getting a good seal with them.

I really do not want to do that either. I was throwing it out there to see if it could even be considered.

 

[Goldie]

So in other words, you have a case of drooling banjos?

Don't get up, I'll see myself out.

That is really, really funny.

 

[Jack T]

Get a tube of PTFE pipe sealant and coat the threads / washers with it. Worked a treat on the banjo fittings at my fuel pump and fuel rail.

 

[BoyRacer]

It is very common for the banjo washers to leak. Use a box end wrench - 13/16th if I remember correctly. Back off each banjo a quarter of a turn and then re-tighten. It usually takes a lot more than just snug. Don't use pipe sealant. It's messy. A drop or two of oil on the threads and washers will help with tightening if my first tip does not do the trick.

 

[Bob_Spidell]

"... 13/16th if I remember correctly ..."

You do. I've always wondered if that is actually intended, or if it just happens to fit a Whitworth--or other wonky Brit thread--size. IIRC, there is no SAE socket/wrench that fits the smaller bolts on the float bowl drains.

 

[DaeB]

"... 13/16th if I remember correctly ..."

You do. I've always wondered if that is actually intended, or if it just happens to fit a Whitworth--or other wonky Brit thread--size. IIRC, there is no SAE socket/wrench that fits the smaller bolts on the float bowl drains.

Both are Whitworth.

 

[Goldie]

Thanks to all who responded---including the humor. I ended up soaking new fiber washers in Marvel Mystery Oil. That seems to have solved the seeping. I also found out that there are alloy washers available for HD8 carbs on Moss in the Jag parts.