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Oil tank leak
#817124 07/23/20 5:23 am
Joined: Jan 2014
Posts: 611
BigBars Offline OP
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HI folks, my oil tank was leaking from the rear bracket. Tank seems sound with no rust inside or out. I expected to find a crack from vibration, however it almost seems as though the oil was coming from under the weld. It was clearly coming from one point (at the arrow). Best to just braise it up?

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Re: Oil tank leak
BigBars #817128 07/23/20 6:05 am
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Yes, silver solder or braze works best.

Re: Oil tank leak
BigBars #817140 07/23/20 10:58 am
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Welding is best, once brazed you can never weld without extensive surgery as braze contaminates the joint. Gas or TIG will work on thin metal and a skilled welder.

Re: Oil tank leak
BigBars #817143 07/23/20 11:53 am
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If that black spot is the hole, then I agree with Kommando, I would not braze there. One zap with the mig welder is what I would do. I think that is easiest for the thin sheet used here and requires less skill. Access might be a problem for any type of welding process, I'm not sure from the photo. That is an excellent photo, by the way.

Re: Oil tank leak
BigBars #817227 07/23/20 9:11 pm
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I would normally favor brazing for a repair such as this.
However:
-- Kommando is correct--if you try brazing and it doesn't work you have loused up if you then try to weld it.
-- You need to get it oil free and that is difficult.

Why would I prefer brazing?
Because welding can leave the part brittle and liable to vibration cracking in further service.
Just my motorcycle engineering apprenticeship from a wizened old Welshman ---one of the best engineers I have ever met--and never spent a day in college.
His words "Never weld anything on a bike---just braze or Sif-Bronze weld"

Best of luck, Bigbars!

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Re: Oil tank leak
BigBars #817290 07/24/20 8:33 am
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My experience exactly Tridentman....we would weld the tanks and it always cracked around the welded area. Tried MIG and TIG with the same result. Brazing doesn't need the same heat. And tanks I've repaired have stayed repaired.
BTW, the MIG weld actually cracked as it cooled. That tank is just too thin and going by the shape we thought probably stressed.

Re: Oil tank leak
BigBars #817295 07/24/20 11:08 am
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+1 ^
Unless your welder is St. Eligius, the differential heating of the welding process seems to create more problems than it solves.
I ended up taking the tank to a radiator shop. All good.


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Re: Oil tank leak
BigBars #817419 07/25/20 1:49 pm
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Why not just silicone it over!!


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