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I have a 2008 Honda Civic LX automatic transmission sedan with 130,000 miles. I noticed the brake pedal was feeling weird, but still drivable. I performed an oil change and noticed fluid under the car (not on the ground) on the drivers side. Looked like fluid had splashed when I looked up from underneath into the underside of the car. I checked under the hood and the brake fluid reservoir looked empty. I checked my front brake pads on both sides and they look fine.
Under the hood, I noticed a fluid/moisture between the valve cover and the air box that holds the air filter. I attempted to remove the air box (I watched YouTube videos) but was unsuccessful. The rubber parts were very difficult to free up, and the connection on the left (the one that isn't a bolt) is tricky as well.
Anyway, if anyone has any ideas of what might be leaking, maybe I don't need to remove the air box. I have attached photos of the moisture I see. I wasn't able to get any shots from under the car. I assume it's brake fluid? Maybe I need a new master cylinder?
I apologize in advance as I am not an expert on car parts and what they're called. Note: I replaced the valve cover gasket in April, 2020, so I assume it's not oil? I bled the brakes with new DOT 3 fluid in April, 2020 as well.
EDIT: I was able to remove the air box! I have attached photos that show the moisture. It appears to be coming from the left of the air box. I assume it's brake fluid but I'm not 100% sure. It looks like the valve cover gasket is still in good shape, and not leaking from there. I checked the master cylinder and it looks dry. There is a hose that runs from that big black circle (brake booster??) to the back of the engine, and that seems dry too.
I have attached photos and hopefully someone recognizes where the leak is coming from.
Thanks!
Last edited by joenobodyyet; Dec 14, 2022 at 05:02 PM.
Reason: I was able to remove air box and take better photos.
If it's on the engine it isn't brake fluid, likely oil. I'm not very familiar with the 8th gens but based on where you're looking it could be the camshaft plug. Item 5 in the picture, the seal is 16.
Thank you, I think you're right! I was starting to think it was oil too, because I don't know how brake fluid would be at that location. I think the camshaft seal is on the other side and it's dry, and the valve cover gasket looks dry, but I learned that there is a camshaft thrust plate that has a seal/o ring that can go bad. I think that's the part you're referencing. Here is a video of the repair:
Hopefully that solves the problem of the leak to the left of the air box, but I still need to figure out why my brake fluid reservoir was empty. I'm going to try to drive it around my neighborhood to see if the brake fluid leaks again, and maybe I can see where it's leaking. That might take some time though with the holidays, and I might want to fix the oil leak first.
I don't see any brake fluid where the brake master cylinder meets the brake booster. How would I check it there? Should I remove the 2 bolts to free the master cylinder from the brake booster? Should I remove the 4 bolts in the car behind the brake pedal to free the brake booster?
