O ring Madness

[J_J]

I think this o-ring thing is going to open up a can of worms, like which o-ring should I be using for this or that. I usually try and get the kit for the cylinder that I am rebuilding. I am sure that some of you probably pick up something that will fit. Andy of Wayne County is right. Is substituting good enough? Probably not in a lot of cases. It's always good to have the right parts, and not have to know what the material is made of. I just get the kit and replace the o-rings in order. I know the material is different on the o-rings and seals, but I don't care if I have the manufactures kit.

 

[Wayne County Hose]

J_J- I probably opened that can of worms. But, I felt the need to let people know that an o-ring is not just an o-ring. The auto store kits will work in the vast majority of applications. But, where they don't work is exactly where they will drive you absolutely nuts trying to figure out what the heck is happening and why my stuff won't stop leaking.

Getting the right kit for what you are working on is the best way to go. Whenever I work on a cylinder at my shop, I always try to get the kit for that particular cylinder when I can. It's the easiest way to go.

 

[EddieWalker]

OK, now I'm nervous. What happens if I put the wrong hardness O Ring in a fitting? If it doesn't leak, does that mean I got lucky?

I never thought about how hard an O Ring is, or that there are differnt levels to this. If I have the right size in my kit, then that's what I use.

Eddie

 

[Bird]

Whenever I work on a cylinder at my shop, I always try to get the kit for that particular cylinder when I can.

And it was just almost an absolute necessity when working on air tools.

 

[Wayne County Hose]

OK, now I'm nervous. What happens if I put the wrong hardness O Ring in a fitting? If it doesn't leak, does that mean I got lucky?

I never thought about how hard an O Ring is, or that there are differnt levels to this. If I have the right size in my kit, then that's what I use.

Eddie

Fitting o-rings are generally 70 durometer, the hardness in your general kit. Flange o-rings are harder, 90 durometer. I didn't mean to put a scare into anybody about their o-rings. Go ahead and keep using your kits like you always have. Just be aware that if you have installed a new o-ring and you still have a leak, that maybe you need a slightly different o-ring.
Flat face fittings that use an 0-ring are a different size than you find in most generic kits. They tend to be smaller diameter. Using one too thick will probably result in a leak. I hope this clears things up. Don't worry about what you have always done that works. Worry about it if it doesn't work.

 

[J_J]

J_J- I probably opened that can of worms. But, I felt the need to let people know that an o-ring is not just an o-ring. The auto store kits will work in the vast majority of applications. But, where they don't work is exactly where they will drive you absolutely nuts trying to figure out what the heck is happening and why my stuff won't stop leaking.

Getting the right kit for what you are working on is the best way to go. Whenever I work on a cylinder at my shop, I always try to get the kit for that particular cylinder when I can. It's the easiest way to go.

Really, I don't mind at all. It is good that someone can point out those things in life that that we know so little about. Heck, I never considered metric o-rings, nor did I ever try to figure out the type of material the o-ring or seals was made of. I did a search on the Internet for o-rings, and was amazed at the different material that is used in o-rings and seals. In some life and death situation, you have to have the correct o-ring/seal installed and the correct fluid. How about that o-rings and seals on that 747 landing gear? Wrong type and wrong fluid. and a lot of people could be in big trouble. I think some of you are getting by with using what you have, and yes you are lucky. I would guess that there is probably only 1 in 10,000 people that could pick out the correct o-ring out of a bucket full of mixed up o-rings.

I have books and CD's on hydraulics, but did not dwell to much on o-rings.

So Andy, how about a lesson in o-rings and seals.

Another question would be that that those of us that use motor oil in our hydraulic systems, will the o-rings and seals last as long or harden or deteriorate?

I have pulled out o-rings that were flat,hard and would crumble.

On the hydraulic lines they say oil resistant, but what is breaking down the inside of the lines. Is it acid build up or what?

 

[woodlandfarms]

Wow, talk about learning something new. To everyone (especially Wayne County) thanks for the lesson. I have always been bedeviled by O-rings. I should have asked this in a general forum and not PT specific.

Waynecounty. Thank you for your offer and one of these days I will take you up on it.

Because of my lack of local parts here in Woodland I am going to just have PT mail me the proper set on Monday. Hopefully the $50 per minimum order will not be in the cards as I allready got a bunch of overpriced stuff from them and this was supposed to be in the package.

Again. Thanks for the info....

 

[Wayne County Hose]

You know, J_J got me thinking. I'm sure all you remember the space shuttle that blew up on take off back in the '80's. It exploded because of an improper o-ring. No, your tractor won't explode if you put the wrong one in, but there are times when it is important.
I'm probably fairly knowledgable on o-rings and seals but I am by no means any kind of expert. There are literally so many kinds of o-rings, then if you want to get into seals, we could be talking a long, long time. Best advice I can give is if you are in doubt, ask.

 

[toy]

Wow, talk about learning something new. To everyone (especially Wayne County) thanks for the lesson. I have always been bedeviled by O-rings. I should have asked this in a general forum and not PT specific.

Waynecounty. Thank you for your offer and one of these days I will take you up on it.

Because of my lack of local parts here in Woodland I am going to just have PT mail me the proper set on Monday. Hopefully the $50 per minimum order will not be in the cards as I allready got a bunch of overpriced stuff from them and this was supposed to be in the package.

Again. Thanks for the info....

Our auto parts store caters to a lot of heavy equipment customers and they have the same kit that we use at work, and those kits are used on hydraulics. I never considered that in some locations they may not have the same demand for the o'rings and therefore might have an inferior quality product that wouldn't be acceptable for our applications.

 

[ponytug]

WayneCounty: Thanks for air the oring issue.

Having lived through oring torture a couple of times, I can relate. There is nothing like trying to size a 15 year old oring off a piece of equipment from a manufacturer that has forgotten what it was- especially if what is being sealed is something nasty or a high vacuum. (For the high vacuum, when I started out, we'd use a telsa coil with a 10" spark to ionize up a plasma that would leak into the vacuum, so we could find the leaks. It was fun with our own little lightening storm, but modern leak testers work better.)

And we haven't even gotten into orings that are square or quad! profile!

Gauges can be helpful if you are dealing with lots of orings.

If I get stuck (prior to WayneCounty's offer) I'd call McMaster Carr, who have been really helpful in sizing/material recommendations over the years to an amateur like me.

Here is a link to small table of oring material compatibility.

All the best,

Peter

Our auto parts store caters to a lot of heavy equipment customers and they have the same kit that we use at work, and those kits are used on hydraulics. I never considered that in some locations they may not have the same demand for the o'rings and therefore might have an inferior quality product that wouldn't be acceptable for our applications.