Can anyone suggest a solution to remove a rusted septic cap that won’t budge even with WD40 and a sledgehammer?
Asked by Herma Kehrer 
4 months ago
Last Updated: August 7, 2024
I could have sworn I put it up, but I can’t seem to find the post. I’ve got this septic cap that’s made of cast iron. It’s been a few years and now I can’t get it to budge. I tried WD-40 and even a sledgehammer, but no luck. It seems like the cap is stuck to the rim because of rust. Any other ideas on how to get it open?
Lots of heat… Seriously, like using a blowtorch to break it free… And then cool it down, obviously haha
Is going to attempt
Thinks it might break, but at least it will be removed and you could consider getting an aluminum or steel cover instead
Is thinking about painting later
WD-40 isn’t really meant for loosening stuck bolts
Said no, but mentioned that it acts as a penetrating solvent.
Mentioned that wd40 is a combination of white spirit and inexpensive oil. His former boss used to fill up the containers in the United Kingdom.
Hey, keep using that sledgehammer, make sure to clean out all around the edges as much as possible. Try using a knife or splicers knife. Keep pounding all around, and have someone watch to see when it’s starting to break loose. Good luck with the DOT experience. I don’t miss it. They do make a puller, but you still need to break it loose first.
Use a hammer drill on the hammer setting only. The vibrations should help dislodge it.
You should give a proper penetrating oil a shot, such as Kroil. Give it a generous spray, leave it for some time, and then give the lid a good whack with a heavy hammer to see if it loosens up. And if needed, do it again. Best of luck.
Thank you, Bushek
It may seem extreme, but try saturating the joint with penetrating oil. Create a hole in the center, around 3/8 size. Insert a bolt and gently apply upward pressure while tapping the cap with a hammer. ‘t forget to seal the hole once done.
So, is there a specific square key meant for that square hole? And if yes, did you manage to unlock it?
Hey, do those come with a lock? The one with the square hole? Have you got the key for it?
Thinking about trying to open it right now during the hot summer weather? Maybe consider waiting until the fall or after a few chilly days. The heat causes the metal to expand, so it’s likely more snug currently compared to colder temperatures.
During last fall in December, gave it a try.
Used dry ice.
Why don’t you cool it down with some water first and then try using a bigger hammer
Try hitting it with a sledgehammer first, you’ll see it pop and then you can use a pickaxe to remove the manhole cover
You definitely need a key for those locked doors
To solve this, I attached a chain with a hook to a forklift. The rim and frame are stuck due to dirt and debris.
Check out this Reed Tool MKDT Meter Box Key for Ductile T Skeleton on Amazon
Make sure to use this key to unlock it, but be gentle until you have the key. Remember, if the key doesn’t fit, Amazon offers free returns.
I didn’t require a key the last time I opened it.
There is likely a tool available at your local auto parts store that can be used to assist in pulling it open. You can rent a key and a slide hammer for free and use them together to help open it.
Utilize the key
Matthew Francis Murphy, they are attached with screws on the sides. There is no key involved. I constructed the house recently and managed to remove it before.
This requires a key as it is currently locked.
Back in the day in construction, we would stick the pointed end of a pick-axe into one of the holes to lever it out.
Gave it a shot, but it didn’t pan out.
You have the option to create something similar to this…
https://youtu.be/ywrK9l0AG48
If it’s threaded, attempt to unscrew it
Nope, it’s definitely not .
You should contact the teenage mutant ninja turtles, they can help with opening it
Heat levels?
When trying to loosen something, hook it and give it a good whack with a sledgehammer simultaneously
Some of them come with a cam lock on the interior that needs to be unhooked to release the lid. If you notice it’s loose and not opening, it probably has one.
Try using a 1/2” breaker bar on that square! You should be able to loosen it by turning it. The bolts you removed were likely securing it. The breaker bar will help you loosen it
Hey, , I believe the rust is what’s keeping the pieces stuck together. Even when I tried hitting it with a sledge hammer, those seams didn’t budge at all. And there’s no bolt there anymore.
I get it, Aungtun. So, basically, there’s a square notch that resembles a 1/2” breaker that can be used to break the rust, right?
You might want to consider using a sledgehammer to help break it loose initially.
Hey , I gave it a shot
Hey, it’s ! ☝️☝️☝️👍
Warm it up
A crucial element
Actually, all those answers are incorrect. What you should do is insert a leverage bar into the hole and gently pry it up.
Remained completely still when we attempted to move him.
You should consider getting a longer and sturdier pipe for better leverage.
I’m six feet tall