Crush washer truth

“Nothing bad has happened when I do this”.

That is your argument, and that is precisely the logic used by NASA administrators that led to the Challenger disaster.

It is called “normalization of deviation”.

You do things the wrong way*, without consequence, over and over and you begin to believe that your way is good enough.

Until it isn’t.


*In the case of NASA, it was ignoring Morton-Thiokol’s recommendation about temperature limitations for O-ring sealing. Ironic, isn’t it? We’re talking about O-rings and sealing. Now, nobody’s gonna die from an oil drip out of your car.

But your argument is that nothing bad has happened..exactly what NASA administrators argued.
When my rocket explodes , you can say you were right . Until then .. 🤓
 
“Nothing bad has happened when I do this”.

That is your argument, and that is precisely the logic used by NASA administrators that led to the Challenger disaster.

It is called “normalization of deviation”.

You do things the wrong way*, without consequence, over and over and you begin to believe that your way is good enough.

Until it isn’t.


*In the case of NASA, it was ignoring Morton-Thiokol’s recommendation about temperature limitations for O-ring sealing. Ironic, isn’t it? We’re talking about O-rings and sealing. Now, nobody’s gonna die from an oil drip out of your car.

But your argument is that nothing bad has happened..exactly what NASA administrators argued.
Astro, 2 things can be true at once. Crush washers can be designed for single use but can still work for more than that.
The fact that so many crush washers have been reused without incident is pretty solid evidence. Again, a visual inspection plays an important role.
Because I have reused a crush washer does not necessarily mean I short change everything.

Use cases like NASA, surgery and the like can have severe consequences for part failure. I think it's fair to say the oil plug-to-pan seal is not under much pressure...
Respectfully, IMO your analysis makes too many assumptions. Real world use shows otherwise.

Your thoughts? Heck, I don't even flip 'em over and take care not to over torque!
6 pages and counting...
 
Astro, 2 things can be true at once. Crush washers can be designed for single use but can still work for more than that.
The fact that so many crush washers have been reused without incident is pretty solid evidence. Again, a visual inspection plays an important role.
Because I have reused a crush washer does not necessarily mean I short change everything.

Use cases like NASA, surgery and the like can have severe consequences for part failure. I think it's fair to say the oil plug-to-pan seal is not under much pressure...
Respectfully, IMO your analysis makes too many assumptions. Real world use shows otherwise.

Your thoughts? Heck, I don't even flip 'em over and take care not to over torque!
6 pages and counting...
Again, the argument “nothing bad happened” is weak. Specious.

You cannot define best practice on the basis of “nothing bad happened”.

Look, we are talking about amateurs changing oil. Low consequence. Nothing bad will happen with a drip. Further, not a lot of people in this group who have access to, or follow factory maintenance practices.

Deriving principles, or even simple failure analysis, from the behaviors of this group is both flawed and pointless.

Amateurs take shortcuts. I get it. No worries. You do you. What’s the worst that happens, a few drips?

But that will not ever convince me it is OK to take those shortcuts.

I have a couple of cars that run hydraulic suspension systems at 2,700 PSI. They use o-rings to seal. Mercedes requires those o-rings be replaced every time. A leak there can cost you dozens of hours and thousands of dollars in failed components.

I do not take shortcuts. I do not engage in amateur practices.
 
I will not be a hypocrite and say I have not reused a crush washer but that was only because I had no choice and assumed that risk. If doing customer paid work, I would not entertain that if the expectation or requirements call for replacement.
 
Again, the argument “nothing bad happened” is weak. Specious.

You cannot define best practice on the basis of “nothing bad happened”.

Look, we are talking about amateurs changing oil. Low consequence. Nothing bad will happen with a drip. Further, not a lot of people in this group who have access to, or follow factory maintenance practices.

Deriving principles, or even simple failure analysis, from the behaviors of this group is both flawed and pointless.

Amateurs take shortcuts. I get it. No worries. You do you. What’s the worst that happens, a few drips?

But that will not ever convince me it is OK to take those shortcuts.

I have a couple of cars that run hydraulic suspension systems at 2,700 PSI. They use o-rings to seal. Mercedes requires those o-rings be replaced every time. A leak there can cost you dozens of hours and thousands of dollars in failed components.

I do not take shortcuts. I do not engage in amateur practices.
Disagree. If the washer is in good shape, it can perform as good as a new one assuming proper installation. This is not my opinion; real world results bear this out.
I am not sure how amateur affects that.

The high pressure system you refer to is a different application. I would never reuse a washer on a fuel injection system, brake caliper hose, etc. You probably know better than I, but oil pan psi is about 45, right? That's only 3x standard atmospheric psi, not much to seal.

I suggest your points are correct, but would argue they are not an apples-to-apples comparison.
I would never say there is anything wrong with your oil change procedure, just that other practices can yield similar results.
I appreciate your thoughts. Good conversation.
 
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IIRC my olds cieras had a flat copper washer on the drain bolt, not like a crush type. I never changed it, it didnt leak either.

That's a lot of what is going on here. I bet very few people have or re-use actual crush washers. A lot of people re-use soft metal somewhat crushable flat washers.
I think you are correct Pablo. Are people really reusing really crush washers or flat copper washers? I won't reuse a true crush washer.
 
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Disagree. If the washer is in good shape, it can perform as good as a new one assuming proper installation. This is not my opinion; real world results bear this out.
I am not sure how amateur affects that.

The high pressure system you refer to is a different application. I would never reuse a washer on a fuel injection system, brake caliper hose, etc. You probably know better than I, but oil pan psi is about 45, right? That's only 3x standard atmospheric psi, not much to seal.

I suggest your points are correct, but would argue they are not an apples-to-apples comparison.
I would never say there is anything wrong with your oil change procedure, just that other practices can yield similar results.
I appreciate your thoughts. Good conversation.
The oil pan is at atmospheric pressure. It is not pressurized at all.
 
But that will not ever convince me it is OK to take those shortcuts.
I'm not trying to convince anyone of anything, just stating facts. If it doesn't leak with the same washer then it didn't need a new one.

If you're dead set on always replacing the washer, then you don't really have evidence to the contrary, are just repeating something you heard somewhere? Crush washers that don't deform much if at all, because they aren't torqued as much, and aren't holding a lot of pressure, can be reused. Someone mentioned whether they were even crush washers and I suppose not, if not torqued down enough to deform substantially.

Any theories otherwise would ignore their purpose which is to seal so there isn't a leak, which I accomplish reusing them. Oil pans are not brake calipers, which have crush washers that I do always replace. It's true that I'm not a pro oil changer, but I've been doing it over 40 years so I think I've gotten the hang of it. ;)
 
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I'm not trying to convince anyone of anything, just stating facts. If it doesn't leak with the same washer then it didn't need a new one.

If you're dead set on always replacing the washer, then you don't really have evidence to the contrary, are just repeating something you heard somewhere? Crush washers that don't deform much if at all, because they aren't torqued as much, and aren't holding a lot of pressure, can be reused. Someone mentioned whether they were even crush washers and I suppose not, if not torqued down enough to deform substantially.

Any theories otherwise would ignore their purpose which is to seal so there isn't a leak, which I accomplish reusing them. Oil pans are not brake calipers, which have crush washers that I do always replace. It's true that I'm not a pro oil changer, but I've been doing it over 40 years so I think I've gotten the hang of it. ;)
Just about every factory service data on a vehicle with these crush washers says to replace them each time. I do not think it is something just heard somewhere but stated as a best practice.
 
I'm not trying to convince anyone of anything, just stating facts. If it doesn't leak with the same washer then it didn't need a new one.

If you're dead set on always replacing the washer, then you don't really have evidence to the contrary, are just repeating something you heard somewhere? Crush washers that don't deform much if at all, because they aren't torqued as much, and aren't holding a lot of pressure, can be reused. Someone mentioned whether they were even crush washers and I suppose not, if not torqued down enough to deform substantially.

Any theories otherwise would ignore their purpose which is to seal so there isn't a leak, which I accomplish reusing them. Oil pans are not brake calipers, which have crush washers that I do always replace. It's true that I'm not a pro oil changer, but I've been doing it over 40 years so I think I've gotten the hang of it. ;)
Yeah , but there's NASA and all of that .... :LOL:
 
Just about every factory service data on a vehicle with these crush washers says to replace them each time. I do not think it is something just heard somewhere but stated as a best practice.
And that same service manual will say that the ATF is lifetime and doesn’t need changing.

Who on here does everything by the manufacturer’s book to a T? Every single requirement, every single step, every single special tool they want you to use? Let’s have a show of hands.
 
Just about every factory service data on a vehicle with these crush washers says to replace them each time. I do not think it is something just heard somewhere but stated as a best practice.
I'd ask you to substantiate that, but I do recognize that it would be unreasonable for you to quote just about every factory service data source.

At the same time, it would be interesting to see which ones you are thinking of and see some owner reports of leaks because they didn't replace the washer, yet did torque the drain plug to the spec'd amount? If there's some really crappy irregular surfaces on some oil pans out there, I am not trying to convince someone to live with leaks in that situation.

If you don't replace the washer and it leaks, and it was never over-torqued , then I consider that proof that the washer needs replaced routinely, at least more often if not every time. I have never been in that situation. I don't let shops change my oil. It's amazing what can go wrong that you never imagined even if it's just probing for something else to up-sell.
 
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I'd ask you to substantiate that, but I do recognize that it would be unreasonable for you to quote just about every factory service data source.
Nor would I waste the time for something so obvious, especially with the Asian brands that usually tape one to the oil filter box when you buy them from the dealership.
 
I have an old Mazda 5 and it now has over 150K on it. The original washer was reused and eventually became one with the drain plug. Never a problem.
 
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