Vacuum Pump Oil Feed Line Leak

[Iron Duke II]

I'm struggling to locate the last post I recall on this subject on the forum. However, I replaced the line some time ago and had no leaks until recently. The drips are not heavy and do not reach the ground, and appear to be coming from the jic connection. The connection is still snug, so do not believe further tightening may help. Did I get a possible faulty part? After reading another post from a different diesel forum it is not recommended to use any sealant if this occurs, however a connection on the VP may need to be replaced. Did not notice any issue with new Cummins hose or the existing fittings when I installed it before. Here is what the fitting appears to be on VP. https://www.summitracing.com/search...delmann-sae-45-degree-to-npt-adapter-fittings

 

[BigPapa]

The fittings you reference are SAE 45* “bull nose” fittings, not JIC which are 37*. Did you replace your fitting with a 45*?

 

[Iron Duke II]

No sir. Jic was apparently the incorrect nomenclature used in my comment. This is the hose I installed before that is the leaking item fastened to the VP. https://www.genosgarage.com/product...k-oil-line-3923084/engine-replacement-parts-2

I came across the following which includes a similar situation. https://www.cumminsforum.com/threads/vacuum-pump-oil-line-leak.2416258/

Thanks for the correction.

 

[BigPapa]

Again, the Edelmann PN 148420 referenced on Cummins Forum is SAE 45*, not JIC. The Cummins fitting in the VP, 68138, is 37* JIC.

JIC fittings typically don’t have sealing issues unless they’ve been severely over torqued or damaged by something bumping or dragging across the sealing surface.

If you’d like to get one from Amazon, ASIN is B07GM1X4SX.

 

[Iron Duke II]

Again, the Edelmann PN 148420 referenced on Cummins Forum is SAE 45*, not JIC. The Cummins fitting in the VP, 68138, is 37* JIC.

JIC fittings typically don’t have sealing issues unless they’ve been severely over torqued or damaged by something bumping or dragging across the sealing surface.

If you’d like to get one from Amazon, ASIN is B07GM1X4SX.

This is the item that comes up on Amazon using ASIN B07GM1X4SX.

This website has an example that appears more like what is in the VP. https://puredieselpower.com/dodge-p...-valve-cummins-vacuum-pump-fitting-68138.html

Presume a new line will be needed as well.

Thanks

 

[Iron Duke II]

Is there a reference for the size of the 37* JIC fitting on the VP?

JIC 37° Flare (SAE J514)
Widely found in hydraulic systems, both the JIC male and JIC female of this connection have a 37º flare seat as well as straight threads. The flare seats of the male and female seal together when the straight threads are joined. The straight threads of the each half hold the connection together mechanically.

Note: While most SAE J514 threads look identical to SAE 45º flare threads, their seating angles do not match.

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Inch size Dash size Thread Size Male Thread O.D. (in) Female thread O.D (in)
1⁄8 -2 5⁄16 - 24 5⁄16 0.31 9⁄32 0.27
3⁄16 -3 3⁄8 - 24 3⁄8 0.38 11⁄32 0.34
1⁄4 -4 7⁄16 - 20 7⁄16 0.44 13⁄32 0.39
5⁄16 -5 1⁄2 - 20 1⁄2 0.50 15⁄32 0.45
3⁄8 -6 9⁄16 - 18 9⁄16 0.56 17⁄32 0.51
1⁄2 -8 3⁄4 - 16 3⁄4 0.75 11⁄16 0.69
5⁄8 -10 7⁄8 - 14 7⁄8 0.88 13⁄16 0.81
3⁄4 -12 1 1⁄16 - 12 11⁄16 1.06 1 0.98
7⁄8 -14 1 3⁄16 - 12 1 3⁄16 1.19 1 1⁄8 1.10
1 -16 1 5⁄16-12 1 5⁄16 1.31 1 1⁄4 1.23
1 1⁄4 -20 1 5⁄8 - 12 1 5⁄8 1.63 1 9⁄16 1.54
1 1⁄2 -24 1 7⁄8 - 12 1 7⁄8 1.88 1 13⁄16 1.79
2 -32 2 1⁄2 - 12 2 1⁄2 2.50 2 7⁄16 2.42

https://www.flaretite.com/high-temp-oil-and-steam-37.html

• 37° JIC 316 SS High Temp. Oil and Steam

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• 316 Stainless steel seal with Loctite high temp graphite coating for Nickel plated and 316 SS fittings.
• Rated for -40 to 1200 F temperature and all common gases, fluids & steams.
• Available in JIC (US Standard), 37 degree flare, for inch tubing sizes, for inch tubing sizes.

The Flaretite seal is sold in the following pack types:

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Note: The number of Flaretite seals per pack type varies according to the size of seal.

See overview section for quantities per pack.

Availability: In stock
*Size

 

[BigPapa]

Amazon’s image is generic, but the description is correct. It’s 1/8” MP to #4 male JIC. I’ve never used any of those seals. In my opinion, not necessary. If yours is leaking, there’s damage or trash on one of the sealing surfaces.

 

[Iron Duke II]

That's what I don't understand. It didn't leak from Nov. 2018 when the pump was resealed, until I noticed a few drips on the hose (and an oily pitman arm) this last May. I have noticed that Geno's uses the following as a part of the description for the hose, "Over time, engine vibrations can cause this oil line to start leaking", as if this is regular replacement item. https://www.genosgarage.com/product...k-oil-line-3923084/engine-replacement-parts-2

Regardless, add another to do.