O ring Madness

[woodlandfarms]

Well, I think Terry let me down. Wondering if you guys have a solution before I wait a week for my package to arrive.

My tram pump... It has all sorts of hex bolts that act as plugs. Those plugs are leaking. I was thinking of just taking out all the o rings and putting in new ones but now I am not sure of a source, or what size for that matter.

Any thoughts?

 

[MrJimi]

HF has a large assortment of O rings but I would go with a better quality like we have ACE HARDWARE stores around here or an auto part place, bring bolts with you for proper fit

 

[toy]

Well, I think Terry let me down. Wondering if you guys have a solution before I wait a week for my package to arrive.

My tram pump... It has all sorts of hex bolts that act as plugs. Those plugs are leaking. I was thinking of just taking out all the o rings and putting in new ones but now I am not sure of a source, or what size for that matter.

Any thoughts?

Glad to see you are getting a handle on all your leaks and hope your next post will be no more leaks. Auto parts place to get the orings. Wonder how much a whole box assortment of orings would cost. Sounds like soon you will get the upper hand on those leaks and will have a lot of experience to boot.

 

[MrJimi]

HF prices are good take a look at this 382 piece set and this 205 piece set, better quality heck, here is the link to all of them, 4 pages worth I wish some O rings would fix my leaks
J_J is always after me to git them fixed and some day soon I will take him up on it
Jim

 

[Bird]

I needed just one or two o-rings last week and got them at our local Ace Hardware store. When I was repairing mechanics' air tools, I kept lots of o-rings on hand; everything from very tiny ones to about 3" diameter. I often wished they didn't make so many sizes. For some jobs, an o-ring of approximately a certain size will work, while other jobs require o-rings of exactly a certain size and the sizes may be so close that you can't tell the difference visually.

 

[EddieWalker]

I have two kits of O-Rings that seem to cover ever size. I've had them for four years and use them all the time. I think each kit was about $20 each at my Hydraulic Hose store. They sold a bigger kit that had all the O Rings in it for $30 or $35, which I should have bought. I made the mistake of buying one kit, then a few months later realizing that I needed more choices in sizes.

For what it takes to take apart a fitting, I wouldn't take the chance on cheap O Rings. Do it once with quality parts and not have to do it again.

Eddie

 

[Wayne County Hose]

If you send me the o-rings, I will mail you back the proper ones. I have over 2,000 different o-rings in stock. O-rings are much more complicated than people think. Are they 70 durometer or 90 durometer? Are they nitrile or EPDM? Don't be fooled, there are different o-rings for fittings than you get in a generic kit.

By the way Eddie, I agree, move #10 up the list.

 

[J_J]

If you send me the o-rings, I will mail you back the proper ones. I have over 2,000 different o-rings in stock. O-rings are much more complicated than people think. Are they 70 durometer or 90 durometer? Are they nitrile or EPDM? Don't be fooled, there are different o-rings for fittings than you get in a generic kit.



OK , now that you told us that there are different types of o-rings, and size, how does the average person tell the difference, and what is a durometer?

 

[Bill Barrett]

Yep o-rings can be fun. I have a small assortment of good ones 80 bucks. Durometer to o-rings is like rockwell to steel

 

[Wayne County Hose]

OK , now that you told us that there are different types of o-rings, and size, how does the average person tell the difference, and what is a durometer?

Durometer is the hardness of the o-ring material. The higher the number, the harder it is. You can either buy a durometer gauge, or, with experience, stick your thumbnail in it and see how far it goes.
Most hydraulic o-rings are nitrile. There are also fluorocarbon o-rings for other hyd applications. Some of this depends if the o-ring is static or in a reciprocating application. I won't even get into quad rings.
I don't mean to scare anybody off here. If you are talking about simple plugs, then your average auto store 70 durometer kit should be okay. I wasn't trying to make a sale here as I do not charge for o-rings. If you mailed them to me in a self addressed stamped envelope, I would send you new ones for free. It's not worth wasting the invoice. You just have to be careful as on your average tractor, there are at least 5 different types of o-rings that I can think of off the top of my head. Flange seals are 90 durometer. I have seen guys install the 70 durometer rings in and complain because the fitting leaks. That's one reason why I give new o-rings with any fitting requiring an o-ring when I make a hose.
As far as size goes, there is a dash number that corresponds to the diameter of the o-ring cord, then to the inside diameter of the o-ring. There is a chart in the o-ring section of the seal catalog on this website- Hercules Sealing Products. Good technical info here too.

 

[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.