Question Leak

[Yellow C6 Z51]

Hey everyone - hoping for some insight/feedback. I happened to notice a leak underneath my Vette. Left side of the car - about 24" behind the front left tire - and about 12" inward from the edge of the car (almost underneath the area of my front dash behind the steering wheel). It has an oily appearance to it - and it's minimal (like a teaspoon per 1-2 days in the last week or so). I just changed the oil, and I do not believe it's that (levels are great). I also checked my Clutch Master Cylinder and Brake Fluid Reservoir, and both appear to be good.

I took a couple of shots as best as I can from underneath (sorry - they are not great)...

Hoping for some help as to what this might be, prior to taking the car in for a proper inspection. Thank you all!

 

[XFIRE82]

pretty hard to tell from a pic . If it didn't leak before the oil change and does now , then suspect the filter maybe is not tight , or they just didn't wipe all clean when they drained the oil. Either way , you have to left it up on the hoist to see exactly where it is leaking from. Do it soon, as if you keep driving it will continue to splash up the undercarriage and who knows what it is exactly so best to prevent any possible damage asap.

 

[Yellow C6 Z51]

XFIRE82 - good point! Never thought about the oil change affect, seeing it's leaking on the other side of the filter. But, what you said makes sense - and no drip marks this morning, too.

I did not even think about the possibility of oil overspray when the oil drain screw was unplugged. Fortunately, I have a friend who is a semi-retired mechanic with his own shop on his property with two hoists. I'll make a point to go back to have a look underneath.

Thanks again!

 

[XFIRE82]

hopefully that is all it is , when the filter is unturned it usually leaks down on the flywheel cover and not sure where the drain plug is on yours but it can spray off to the sides when he is unturning it. A good mechanic should always wipe everything clean, spray brake clean on a rag is quick and easy.

 

[the-pipe-bender]

Just saw this now. I had the same problem on my C6 coupe. Just one tiny drop every few days or so from the lowest flywheel-screw (according the color it was engine oil). When the car stood in the same spot for several weeks in winter it added up to quite a few drops and created a spot about the size of a hockey puck . . . During the summer and warm weather all was dry - no drops. I finally figured out the problem was the rear main seal which, contracting in cold weather leaked a bit and sealed tight again during warmer temperatures. Annoying but not worth replacing the main seal as this is quite an operation. So I wait until it gets worse.....

 

[Yellow C6 Z51]

the-pipe-bender, thank you! I actually just had the car up on the hoist, and we find the cause - Master Brake Cylinder!!?? We determined it might be the seal, based on following the weeping trail marks.

Funny thing is that it is not drippin any longer (and I am watching my brake fluid reservoir level).

Any Vette members replace this either themselves or via a mechanic?

Also - how pricey is replacing the rear main seal?

Thanks everyone!

 

[XFIRE82]

well that sure turned out un-expected ! , well if it isn't leaking anymore then just leave it and keep an eye on it . Brake fluid is very strong stuff , so not good for it to drip on paint as it will bubble it in no time. As a rule I don't think anyone just puts in a seal , they just replace the whole master cyl .

 

[the-pipe-bender]

XFIRE82 is quite right. If it stopped leaking don't do anything. Just keep an eye on it and monitor. That is what I do about my weeping main seal. A rear main seal itself is just a dollars and cents item. However, to replace it you have to take down half the undercarriage. If you have a mechanic do it it's a job of several hours and a lot of $$$. So I just live with the few drops hanging off the flywheel during cold weather periods.

But if you notice break fluid leaking again, replace the master cylinder as break fluid is quite aggressive.

 

[ddgermann]

XFIRE82 is quite right. If it stopped leaking don't do anything. Just keep an eye on it and monitor. That is what I do about my weeping main seal. A rear main seal itself is just a dollars and cents item. However, to replace it you have to take down half the undercarriage. If you have a mechanic do it it's a job of several hours and a lot of $$$. So I just live with the few drops hanging off the flywheel during cold weather periods.

But if you notice break fluid leaking again, replace the master cylinder as break fluid is quite aggressive.

100% right in my opinion. Got a seasonal seal leak on my H1 and the Tech laughed and said it’s a really a less than amazing $10 part that will take thousands to change and to leave it....unless it becomes obscene. This is on a 20k fresh engine. It’s like a few drips a month. The truck sits 11.25 months of the year. He said driving it it actually better for the seal.

The seal on the Corvette is the same damn thing in principle. Frustrating to experience but a few deep breaths should get you through. It won’t fail catastrophically unless your heavily modded and pushing hard. Then it’s obviously a different ballgame.
So the experts “upscale service writers” quite often have a different agenda than your practical best interest.
Ok just sayin.