Oil filter line leaking

[Ivan_B]

Hello everyone!

 

I have an orange-body-black-cap FRAM bypass oil filter canister installed on my 201'. Finally started driving the car, a couple days ago, and noticed that the bottom (return) line appears to be leaking at the engine side. The leak is so bad that I can see the oil dripping 1.5-2 drips per second after a drive ? I just changed the oil and mismanaged the large rubber filter cap gasket, so the entire cap overflowed all over the engine and it took me a while to realize that it is actually leaking oil on its own, besides the huge spill. I am glad I did not drive very far ?

 

Is this a simple fix of repairing/replacing the line, or a sign of potential issue elsewhere? I've read that there is supposed to be a bypass valve that cuts off the filter somewhere in there. Could it be not functioning properly? The oil pressure stays at a steady ~40 at the gauge.

 

Thanks.

[rallyace]

The way the filter works is that once there is enough oil pressure to open the bypass valve it will direct oil to the filter. It sounds like one of the inverted flare fittings is leaking.  It is not a difficult fix but it can be a real PITA getting the steel lines to fit up properly and starting the fittings without cross threading them.

[Ivan_B]

18 minutes ago, rallyace said:

It is not a difficult fix but it can be a real PITA getting the steel lines to fit up properly and starting the fittings without cross threading them.

Oh, that might actually be the issue. I've noticed that the leaking fitting appeared not threaded all the way in. I attempted to undo and redo it, but it did not thread any further. So, if my oil filter overflowed through the cap, that probably means that the bypass valve is working correctly? In this case, I'll have to drain the filter and take a look at those lines. I've repaired poorly sealing brake lines using a soft aluminum or copper washers before

[Merle Coggins]

You may need to remove the return line and fitting to be able to inspect them properly. If it has been cross threaded, as suggested earlier, you will likely need to replace the fitting and/or make a new line. It's just a piece of brake line that can be bent and flared as needed. 

Also, regarding the oil pressure relief valve. It actually blocks the return flow from the filter when the oil pressure is low. This stops oil from flowing through the filter to ensure the critical engine components receive oil first. The filter is fed directly from the oil pressure galley. 

[DJK]

9 hours ago, Ivan_B said:

Oh, that might actually be the issue. I've noticed that the leaking fitting appeared not threaded all the way in. I attempted to undo and redo it, but it did not thread any further. So, if my oil filter overflowed through the cap, that probably means that the bypass valve is working correctly? In this case, I'll have to drain the filter and take a look at those lines. I've repaired poorly sealing brake lines using a soft aluminum or copper washers before

If it is like mine, the filter canister will not drain with the bottom line off due to the inner tube that goes to the top of the canister.

[Ivan_B]

57 minutes ago, Merle Coggins said:

Also, regarding the oil pressure relief valve. It actually blocks the return flow from the filter when the oil pressure is low.

Thank you for the clarification. Do you know where it is located? Is it inside the filter canister or somewhere in/next to the bottom line fitting on the engine's side? If the valve blocks the return, then my overflowing filter does not prove it is working so I need to inspect it as well.

 

5 minutes ago, DJK said:

If it is like mine, the filter canister will not drain with the bottom line off due to the inner tube that goes to the top of the canister.

Yes, the return pipe has just a couple of small holes at ~3/4 up to the top. I suppose I can just let is sit overnight to drain the excess into the block and then remove the lines, hoping that the oil will stay

[Merle Coggins]

14 minutes ago, Ivan_B said:

Thank you for the clarification. Do you know where it is located? Is it inside the filter canister or somewhere in/next to the bottom line fitting on the engine's side? If the valve blocks the return, then my overflowing filter does not prove it is working so I need to inspect it as well.

 

[Ivan_B]

Thanks!

[Ivan_B]

Took the return line off and found the source of my leak. The return line has a burned pinhole in it, well, actually two pinholes. I've accidentally shorted the starter battery cable terminal to it, recently, and I am very ashamed for what I did ?

It is interesting that I did not notice the hole right away, because I inspected the line after the above mentioned "accident". Also, I could swear it appeared to be dry to the touch, while there was oil everywhere below. Well, I now have to get a new line, and the car should be derivable again.

[greg g]

There have been several incidents of similar oil leaks on here lately, including my note.  I found the flair was cracked within the fitting.  There are only 5 sources for oil leaks on the drivers side of the engine.

 

The filter plumbing, the oil pressure gauge lines especially the rubber vibration line, the base of the distributor to the block and the breather/ fill tube, the screw in plug for the relief valve plunger.

[Ivan_B]

@greg g Thanks for the list, I might just as well check all of these while I am working on this.

 

I've also seen an old thread on this forum, from like 2009, describing the same burning a pinhole in the line with the battery short... Mine also caught on fire, by the way, so I am probably the Darwin's award holder for now ?

Edited July 13, 2023 by Ivan_B

[greg g]

Good luck.  It s probably a simple fix, though potentially messy.