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Cat pump valve orings

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Can someone tell me what size oring goes on these valves? next to the back up ring. I think I know but the battery just went out on my mic.
 

MEP001

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They're metric. What model pump do you need them for?
 

washnvac

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For the 310 and 5cp2120 I use #13, military spec that I get from McMaster-Carr. I thing a pack of 50 is about $9.
 

Jimmy Buffett

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I ordered a "rebuild kit" from KR that was about $75 for my 5cp that was mostly o rings. Can I just buy o rings like that to fix it? Seemed a little steep for o rings to me.
 

MEP001

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As far as I know, there isn't a "rebuild kit" that contains all the o-rings in the head of a 5CP. There is a kit that has high-pressure seals, low-pressure seals, plunger seals and seal casing o-rings. All the seals are proprietary to Cat. Only the o-ring can be found elsewhere, and it's metric -- not something you'll find at a local shop. The valve o-rings are also metric and can be found through special order; the valve back-up rings are custom-made to Cat's specs. It would probably cost more to have them made than to order them from Kleen-Rite or Windtrax or Dultmeier.
 

MEP001

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They may "work fine," but that's not the correct part.
 

Greg Pack

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OK, I'm resurrecting a five year old thread. I found several bad o-rings on a couple of pumps. These pumps are 15 years old and didn't look washed out, so I'm going to try and replace them. I was searching for the answer on the proper sized O-ring.

If as wash n vac said a #13 works, then by using this conversion table I've come up with a 1.6 mm cross section x 11.11mm ID x 14.28mm OD. That would make mcmaster carr # 9262K144 or zoro #G3410018 the correct o ring, assuming these are 70 durometer.

Having said that, the #13 is only .02 inch off in width and outside diameter.

Question: Does anyone know if these orings are 70 or 90 durometer, i.e are they standard feeling or a harder o ring?
 

cwguy.com

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Just order them from Kleen-rite or your favorite supply house. They don't cost much...
What on Earth are you talking about! The correct part cost $1.31 from KR for just 1 seal! JK :) I believe that would be the correct thing to do. I was just kidding. :)

But.... I was thinking about it and I believe I am cheap enough to purchase all the parts from mcmaster.com also? I would purchase a size smaller and a size larger than you think you need though. Also just give me half of them and we can split the cost and 300 o-rings! LOL :)

Question: Does anyone know if these orings are 70 or 90 durometer, i.e are they standard feeling or a harder o ring?
Also.... I do not even know which Cat pump or orings you are talking about but my guess is 90.
http://www.theoringstore.com/index.php?main_page=index&cPath=367_29
Use 90 durometer hard O-rings for applications with 1500 psi or higher pressures.
 
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Greg Pack

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For a 5CP? https://kleen-ritecorp.com/images/K...5CP Plunger Pump 3120 3130 5120 5150 6120.pdf
part 163 on page 2 and the exploded view is page 3. Just order them from Kleen-rite or your favorite supply house. They don't cost much...
Nothing against KR- I can order from mcmaster carr for less and I'll get them next business day and have enough spares to send you some in the mail.

just pulled one off an existing check valve- it feels softer like most o-rings, so I ordered 70 durometer.
 

cwguy.com

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Nothing against KR- I can order from mcmaster carr for less and I'll get them next business day and have enough spares to send you some in the mail.
I believe KR has gotten better with their shipping prices and shipping times over the last 10+ years?

I would like some orings.... just let me know I will purchase half / some. Also do not mail them! Your shipping will be way to high! JK LOL :)
 

Greg Pack

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Well guys, that o ring I ordered would likely work but is a little smaller than the one off a check valve. I need to find my micrometer and measure one. I'll let you guys know if I find the right one.
 

Greg Pack

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cfcw, do you need to borrow some money? Order the right ones from K/R and spend your time on something more fun.;)
I'm taking one for the team. I know many of you have been asking yourselves "how can I save 68 cents on an oring?" Well, I'm going to find that answer. You're welcome.
 

MEP001

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The Cat valve o-rings and back-up rings are metric.
 

mjwalsh

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Well guys, that o ring I ordered would likely work but is a little smaller than the one off a check valve. I need to find my micrometer and measure one. I'll let you guys know if I find the right one.
cfcw,

We have a kit short of o'rings. So be sure & let us know how it works on the Cat 310. In the past a local Hydraulic cylinder shop came through for us on some exotic o'rings ... have not tried them to match the Cats yet though.
 

Randy

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If you do a search for “O” rings on the internet, you’ll find a zillion of them. All you need to know is the Size, Durometer rating and type of material that the “O” ring made of. My guess would be the “O” ring is Buna-N with a rating 70 Duro. Maybe someone could send a "O" ring sample to one of the big internet "O" ring companies and get an exact match.
 
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