38 ul petcocks

[spudzylla]

Does anyone know if original petcocks for 38 ul can be repaired to be leak (weep) free. Or are there replacements available? My right petcock was modified in the past by someone brazing the outlet tube into the end of the petcock. Thanks Mike

[Sargehere]

Yes, o-rings can be inletted in each side of the tapered center shaft. BigLakeBob knows how to do it.

[spudzylla]

Thanks, how do I get ahold of BigLakeBob?...

[BigLakeBob]

early style petcocks

Mike & Sarge, Well, Sarge I do still have the prototype I made approx. 8 years ago. Still operating a small machine shop just in a different state due to family reasons. Problems with making these petcocks: Cost of manufacture(Sarge, you and I already discussed-need quantity), how many do I make then sit on until they sell, (my outlay of material & time), and most important is liability. A sad point in today's society(and I will use the same example as alot have already used), if someone can buy a hot cup of coffee and still be awarded money, I certaintly could be sued if I fabricate a "leak proof" petcock and for some reason a motorcycle would catch fire(petcock fault or NOT)who do you think would catch the liability suit? I know who. So, since Sarge brought this up, I have not buried the idea of making this style of petcock, just on the back burner still. Would like opinions about these petcocks leaking internally-meaning from gas tank to float needle(not out the ends). Would this be a concern? Bob AMCA#6738

[Sargehere]

Thanks for jumping in here, Bob. I remembered our discussions and knew you had done some work developing sealed original petcocks that Mike was asking about.

The exact size of o-rings to be used, and the depth of its seating ring to squeeze the o-ring the correct amount to prevent the passage of gasoline, while still allowing the handle to turn, are all things to be developed. And if you are doing all of this for someone else, there is today's litigious society, that you are already considering.

Other than that, Mike, Colony already makes reasonable reproductions of Harley-Davidson Motor Company's original design, and they often show up on Ebay (try seller Colony_USA. They appear to sell everything Colony makes). The original petcock part numbers for a 38UL would be 3601-37, left; and 3601-16, right.

Actually, to get back to your original question, have you tried to lap the weeping petcock you have? Bruce Palmer describes a process, from fine lapping compound to toothpaste, on p. 265 of his fine book How to Restore...

[spudzylla]

38 ul petcocks

Sarge and Bob: thanks for the replies. I have had palmer's book for several years now and it has helped me immensely in identifying parts and finishes, etc. I haven't looked at the petcock section yet but I will. When I took the petcocks out of my tanks, I noticed that they were leakers, so I pushed the easy button and posted a couple of questions.

I too had a small machine shop years ago and had to be very careful to avoid any litigation. I know my expectations would be that no gas would come out anywhere but out the end of the tube. Just like new Pingel petcocks for modern (sorry to use the "M" word!) harleys. I will take my petcocks apart to see how they work and seal originally.

I will also start looking for the Colony repros until someone makes some great ones. I know that I will be wanting several sets when they come "available". Thanks Mike.

[Steve Little]

If your taps still have the original coatings and are deemed to be worth the effort, just use fine lapping paste (or toothpaste) to re seat the spindle to the valve body.
Also, when you re assemble the valve make sure the spring has tension to the main body, as this is what pulls the spindle into the body of the valve and causes a seal.

[spudzylla]

Thanks again. I hope everyone is drying out and getting away from the cyclone down there....Mike

[enthusiast]

I did it with toothpaste on my 39 - works well.

[Perry Ruiter]

I did it with toothpaste on my 39 - works well.

What brand? I'd like to avoid it. I don't want to brush my teeth with something abrasive enough to polish metal! ... Perry

[enthusiast]

you are right - just me

try this for your teeth - for sure not abrasive (result even will happen if you take second for petcocks and see how they will work after)

whitelightfront.jpg

take this for the petcocks - I belive it will even work great for your valves and seats (but needs plenty of time)

21_0.jpg

[len dowe]

I use CLOVER COMPOUND 1200 grit...Made by Loctite..It takes awhile, but it works really well.