Found my oil leak - or did I? (ultraviolet dye pics in thread)

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So, over the past few months, I decided to get down to business and identify this small oil leak under my FJ. It was not huge, but if she sits for say 5 days or so, a small puddle is presented to the garage floor. Oddly enough, when running her around town with the engine nice and hot, she does not leak for days - hypothesis being that if it is the oil pan cork gasket leaking, it would make sense as it expands when hot.

Fast forward to a few weeks ago - bought some UV dye and small light (does wonders) and ran the fluid into my engine. Went to a brewery for some beers and got the engine nice and hot. After a few hours, Back home and let her sit. Not a drop of oil. Came back from a biz trip and there was the standard puddle. Now it was time...

Switched on the UV light and was not seeing any major UV around the sides or front of oil pan. But started to see some UV in-between skip plate and pan (most likely a crack from the skid plate welds (but not a TON of UV here)...so will be replacing the pan. Drain plug needs replacing but used new washer and Toyota Seal Packing 103/FIPG sealant for a leak-free application. Then I saw most of the UV at the back of the pan where the flywheel/bell-housing sits. Removed the bell-housing guard and saw a lot of UV at the back of the oil pan.

Curious to know if this looks like the pan just needs a new gasket...someone did a terrible job with the orange sealant here as you can see....but does this look like a new gasket is needed? Or is there another gasket here that it could be? Note: Flywheel area is completely dry and I did sinch up all oil pan bolts to torque spec and in spiral sequence about 2 months ago according to the FSM. At that time, entire left side of pan bolts were really really loose. So the oil leaks are much smaller now.

Interested in any advice.

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Possibly the orange gasket in circle. Its arched and meets the two cork gaskets on the flat. Kind of a beyotch, if engine still in the 40.
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@

liko - understood, but I assume a one piece JDM gasket would be a good bet here when I replace with oil pan. The OEM gasket I think is in 3 parts?​

 
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OEM gasket is one piece.
Yes but responder up top is speaking about a multi piece gasket. Maybe the oem one is one piece..:maybe A/M is then multi piece. Short answer in my mind is to use a one piece gasket.

Update: ok now I am seeing that there is some kind of rubber gasket that is used in those two humps. I assumed the one piece cork gasket goes around the entire area (and humps)…or am I missing something. I’m new to this so pardon my limited knowledge.
 
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middlecalf

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Wouldn’t the rear main seal also be a leak possibility?
 
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I agree, rear main seal could be seeping oil. It won't splatter, it just gets blown rearward from the fan and as you drive. Since you got to drop the pan to get to the seal replace both at the same time.
 
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I agree, rear main seal could be seeping oil. It won't splatter, it just gets blown rearward from the fan and as you drive. Since you got to drop the pan to get to the seal replace both at the same time.
@Paul_A rear I see, but also did some research (good post here), where a bad rear main will show some platter....but if so, to do a rear main, you need to pull transmission, correct? If so, I am not set up for that kind of operation or complexity unfortunately.

I have also seen in some posts (or maybe it was my imagination), that some people use a oil pan seal that also has orange rubber seals that go over the saddles (or front and rear humps). Any idea why this is so? My understanding is the OEM one piece cork gasket is all you need (outside of the ancillary things like gasket sealer, etc).
 

73FJ40

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I agree, rear main seal could be seeping oil. It won't splatter, it just gets blown rearward from the fan and as you drive. Since you got to drop the pan to get to the seal replace both at the same time.
The rear main seal cannot be replaced without removing the flywheel.

The flywheel cannot be removed without removing the pressure plate.

The pressure plate cannot be removed without removing the transmission.

Etc.
 

73FJ40

After another night of rust removal!
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Unless you're OCD, I suggest you try this first:
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First, check that all fasteners are snug.

Clean up the suspected areas with a solvent, and spray a couple coats on.

This won't fix a rear main seal, but may resolve the oil pan leakage at the gasket.

There have been reports of corrosion between the oil pan and its skid plate, leading to pin holes. I have no idea if the sealant will work there.
 
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Every inline Land Cruiser engine I've ever had leaked from the rear main, 2x 40s, 2x 60s, 4x 80s. They never splattered, just dripped. And saved my frames from rusting.

The later 80 models also have pan leaks, but that's not pertinent here.
 

pjohnson

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Every inline Land Cruiser engine I've ever had leaked from the rear main, 2x 40s, 2x 60s, 4x 80s. They never splattered, just dripped. And saved my frames from rusting.

The later 80 models also have pan leaks, but that's not pertinent here.
Fair enough - where then would one expect to see a drip from the rear main then on a 40? Is it right where the back of the pan terminates at the saddle itself? Is it after that? Or before? Based upon the dye that I am seeing, it clearly looks like it is seeping from the pan. At end of the day, I will replace the pan and oil pan gasket and see what happens.
 
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Thanks @73FJ40 for the cheap and dirty tip (ordered today so I can get the most from my recent oil change and do the pan later this year). But I cleaned off the area here and the old orange RTV came off in my hands....pulled some down revealing the orange (?) saddle rubber gasket is very skewed/twisted and not seated properly on the rear.

Took 5 pics you can see below. First Q - is the orange rubber seal you see here - part of the non-oem oil pan cork gasket? Or are these (for the front and rear) on the saddles/humps needed with a 1 piece cork? Just a little confused here. I do not see these orange rubber seals as part of the OEM electronics parts catalog for my JF. Cannot even find these rubber seals on say SOR or any vendor site. But may be that the rubber arched ends are part of the one-piece OEM cork gasket.

Makes sense if the PO just did not take care in positoining the oil pan (if gasket replaced in its 140k miles) on the ends and got twisted. Assume this happens?

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Fair enough - where then would one expect to see a drip from the rear main then on a 40? Is it right where the back of the pan terminates at the saddle itself? Is it after that? Or before? Based upon the dye that I am seeing, it clearly looks like it is seeping from the pan. At end of the day, I will replace the pan and oil pan gasket and see what happens.
Right where yours is leaking
 

POPO AGIE

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My 78 was leaking from the day I bought it with 30 miles on it. When we pulled the 2F for the 155F you could see the oil track from the rear main for over 100K miles. I did not change the oil much because I was always topping it back up.
 

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