Easy way to find hyd. leaks?

I have a slow leak on my 931B that isn't shooting fluid out and there are several steel lines in the area of the leak. I sprayed some degreaser and pressure washed the area and lines as best I could and then dried them with compressed air. I don't have a black light and dye so wondering if there's a simple way to pin point the leak? I've read you can put flour on the lines but thought someone who's done lots of repairs might have a simple way way to find a small leak among several steel lines. Can JIC fittings suddenly develop leaks? The leak is somewhere in the bottom of where there's 4 or 5 steel lines. It's harder to locate because all the lines were wet.

Some leaks sure can be tough to find. Can you get someone to stall out each circuit while you observe the area ? Just my 2 cents.

Just don’t use your hand. High pressure injection injury’s are no joke. Just a random picture from the interwebs.

I have wrapped a Kleenex tight to the line or nut and held it on with tape. Short run and one of the Kleenexs will have oil in it. Have wrapped a sensor the same way to find oil or even antifreeze leak. That is one of my tricks.
Simon C

I know not to use my hand. I had thought about wrapping the lines with tape or some kind of paper. When I go out again I'll see if a line leaked while sitting. Maybe I can run it a bit and see which line is leaking. If all the lines are dry the kleenex idea sounds like a great idea.

Spray on developer for finding cracks in steel, its like spray on baby powder. Normally used on a solvent cleaned surface, then spray dye, whip it off. Then spay the developer, it then pulls the dye out of the crack.

Just the developer would probably work to show an oil leak. I've used dye penetrant before. I think I read baby powder has been used too. I've got a few good ideas I can try. It's one of those things you initially think is going to be a beeatch to figure out but then someone else gives you a simple solution of how they've solved a similar problem.
Thanks for the great suggestions!
I just had an idea. I'll run a kleenex under the lines when I go back out and see if one has oil on it. I think even a very slow leak should still weep a tiny bit when it's been sitting for a couple days.

Brite dyez. I think is what it’s called. I always get it at calt when I’m getting parts. It’s not uv and can change color of fluid as dark as you want. It’s nice when you have trans and hyd running very close together

I couldn't find it on a google search. Could you check on the name?

Coaldust said:

Just don’t use your hand. High pressure injection injury’s are no joke. Just a random picture from the interwebs. View attachment 270461

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There is a guy that left the Amish i saw him and he had his hand all rapped up. I ask what happen he said he was filling for a hyd leak. He about lost his hand over the deal. I dont remember what he did before that but that was the 3th thing within a short span he had did.

Was incorrect on my spelling of it.

Found the leak. It wasn't one of the lines directly under the control valve. It was a line from there going to a bulkhead fitting for loader lift cylinders. It loaked shiney just behind the nut and sure enough was wet on the bottom. It makes sense now that I think about it. That line was black the full length from collecting dirt due to the miniscule leak. The oil ran down it and eventually dripped on the other lines under the control valve soaking the dirt underneath everything. I tightened it very slightly and used the machine for about an hour but it got wet again. I drove back to the shop and took the bulkhead fitting out. I remembered hearing/reading about sealing washers for flare fittings so called my favorite hyd. shop and they had them. I raced to get their before they closed and they had a display of the washers on the wall. They didn't notice anything wrong with the bulkhead fitting. They said maybe the nut split but it was fine. They said the washers are a 1 time deal so if it still leaks I'll have fix or repair the line. They didn't charge me for the 1 washer. They are called Flaretite seals. I'm very confident it will solve my tiny leak. The leak was at the back fitting in the pic.

Flaretite Seal

Never heard of those before. Pretty neat!

I have a set of copper seals that are the same, made by Caterpillar . They fit over JIC fittings nicely and do a good job. They use to be in Caterpillars One Safe Source catalog. If I find mine I will post the part numbers.
Simon C

I remember reading that Cat had them. No idea what they're called? I called my favorite hyd. shop because if they had something would be much easier to deal with than going to Finning. They have a service counter you can just walk up to and tell them what you need. No need to go through a parts guy that has to look them up to get a part number. Not that Finning would be bad but what if the parts guy has never heard of them? The shop I go to not only knew of them, when I walked in immediately noticed the display on the wall. It's great that they pop on over the flare. I'm not sure but thought the Cat ones were just a cone shaped washer and was wondering how you hold it in place. I'm also not sure if the Cat seals have the ribs and Loctite on them. Hopefully it's not raining tomorrow and I can test it out.

I've never seen those but a great idea. Are they available in sets over the internet?

Simon C said:

I have a set of copper seals that are the same, made by Caterpillar . They fit over JIC fittings nicely and do a good job. They use to be in Caterpillars One Safe Source catalog. If I find mine I will post the part numbers.
Simon C

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I found the Cat ones in the "Seals and Miscellaneous Products" section of the Hose & Coupling Guide.

Nige said:

I found the Cat ones in the "Seals and Miscellaneous Products" section of the Hose & Coupling Guide.

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Yep those are handy little parts. Just have to wonder if who ever is doing maintenance at the quarry has any idea of what those things are in the box on the shelf in the shop!

Thanks Nige for Showing where I got that idea from. I only have 2 0f each, but very handy if you need. Hopefully someone else can use as well.
Simon C

Those copper seals do come in handy, occasionally. Sometimes they save the day. I need to restock my collection.