CUCV Oil/Fuel Leak

[jplace1011]

I have a 1985 CUCV and there is a leak, which I’m not sure if it’s oil or fuel. Pardon my uncertainty, I’m not a mechanic or even very mechanically inclined. I thank you for any input.

I just had the valve cover gaskets redone (RTD), as well as an oil pressure gauge installed.

I wonder if it’s a result of the recent work or something else. The good thing is the leak doesn’t appear to be from the upper half of the engine, from what I can tell it’s from the lower third of the engine. The fluid seems to start appearing from around the exhaust pipe on the drivers side and around the back edge of the tire on the passengers side. The fluid also seems to be more prominent on the passengers side.

Anybody have any ideas or input? I’m wondering if it’s the rear main seal (2 mechanics have said it’s not that but I don’t know), flywheel, or a number of other things.

Here are some pics and videos for reference:

When I got home and parked the vehicle I found spots underneath. Pic below

It looks like oil, but once I got underneath and inspected I found a big wet mess. Pics below

I also shot two quick videos:

Sent from my iPhone using Tapatalk

 

[Jeepadict]

I see an oil leak. My standard fare is to get a few cans of brake parts cleaner or carb cleaner to compliment a collection of rags to clean up the mess as well as possible. My wager is the leak is probably pressure related as it is getting spread like crazy as you drive down the road. Once everything is spic-n-span let it idle for a little while and try to find the leak, a clean piece of cardboard will help show the location of the drip. A strong flashlight is your friend. If idle doesn't prosper results, try having someone hold the RPM at 1500 while you investigate underneath. If still nothing I would start making short trips around the neighborhood at low speeds and increasing incrementally after each leak search inspection. I would make sure you ensure the crankcase stays within the operating limits on the dipstick thru out your troubleshooting experience. Once you narrow down your location im sure the gentleman encyclopedias on here can guide you in a good direction if your solution isn't apparent. Be patient, chasing down leaks can be a PITA.

Sent from my SM-G970U using Tapatalk

 

[cucvrus]

Could be anything leaking. Fuel and oil or just oil. Fuel will wash the valley and rear main seal area and make it look like oil. But rear main seal is also possible. Also how well were the heads cleaned and the valve covers prepared before the valve covers were resealed? The valve covers have a lot of hold if they are the original bond / sealer. Were hey bent and were gaskets used or just sealer. Many things can leak oil and it is nearly impossible to tell from the pictures. While you are fixing things get the transmission cooler lines secured back up in place. Good Luck.

 

[frank8003]

My favorite is a spray bottle of DAWN and a cheap HF pressure washer and get it clean. Dawn can clean ducks, used it extensively on the Deuce. Don't be under the thing with it running unless it is all off the ground. Ditto on the really bright flashlight/droplight.
Concur with cucvrus, Might want to look at the transmission cooler line connections first.

 

[Sharecropper]

Another possibility (or a contributing factor to the leak) is a stuck CDR valve and/or stopped-up oil fill cap. The purpose of the CDR valve/vented oil fill cap is to allow for engine vacuum to draw the crankcase gases out and vent the entire engine crankcase with fresh air drawn in through the oil fill breather cap. If either of these are stopped-up or if the CDR valve is stuck in the closed position, there will be excess pressure built-up inside the crankcase, due to piston ring blow-by, which will push engine oil out every nook and cranny. So before deciding on a course of action, I suggest you replace both the CDR valve and oil fill cap, then thoroughly clean/degrease the entire drivetrain, let it dry completely, and then crank it and watch carefully for the source of the leak (if in fact thee is a leak). A new CDR valve and NOS oil fill cap are available from Hillbilly Wizard https://www.hillbillywizard.com/

Hope this helps.

 

[jplace1011]

I have a 1985 CUCV and there is a leak, which I’m not sure if it’s oil or fuel. Pardon my uncertainty, I’m not a mechanic or even very mechanically inclined. I thank you for any input.

I just had the valve cover gaskets redone (RTD), as well as an oil pressure gauge installed.

I wonder if it’s a result of the recent work or something else. The good thing is the leak doesn’t appear to be from the upper half of the engine, from what I can tell it’s from the lower third of the engine. The fluid seems to start appearing from around the exhaust pipe on the drivers side and around the back edge of the tire on the passengers side. The fluid also seems to be more prominent on the passengers side.

Anybody have any ideas or input? I’m wondering if it’s the rear main seal (2 mechanics have said it’s not that but I don’t know), flywheel, or a number of other things.

Here are some pics and videos for reference:

When I got home and parked the vehicle I found spots underneath. Pic below

It looks like oil, but once I got underneath and inspected I found a big wet mess. Pics below

I also shot two quick videos:

Sent from my iPhone using Tapatalk

Thank you for all of your input. Another mechanic is looking at it today. One discussion has been head gaskets.

We will have to see about all of that. In the end more investigating needs to be done. I’ll update again.


Sent from my iPhone using Tapatalk

 

[jplace1011]

Could be anything leaking. Fuel and oil or just oil. Fuel will wash the valley and rear main seal area and make it look like oil. But rear main seal is also possible. Also how well were the heads cleaned and the valve covers prepared before the valve covers were resealed? The valve covers have a lot of hold if they are the original bond / sealer. Were hey bent and were gaskets used or just sealer. Many things can leak oil and it is nearly impossible to tell from the pictures. While you are fixing things get the transmission cooler lines secured back up in place. Good Luck.

Hi there, he used rtd for the valve covers. The mechanic who had it is saying the leak could be a blown head gasket, is that even possible? I thought coolant was what usually leaked.


Sent from my iPhone using Tapatalk

 

[jplace1011]

Hi there, he used rtd for the valve covers. The mechanic who had it is saying the leak could be a blown head gasket, is that even possible? I thought coolant was what usually leaked.


Sent from my iPhone using Tapatalk

It turns out one of the replaced valve covers (passenger side) is slightly leaking. That and the Rear Main Engine Seal is bad. Two mechanics in a row have not fixed the rear main seal problem. It took me and a backyard mechanic to figure it all out.


Sent from my iPhone using Tapatalk