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Hardware, o-ring, washer question

jjoel

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Dec 30, 2011
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I picked up a 6hp pressure washer off of craigslist for $50 (I know I ****). Well it will be a true score if I can get the pressure washer gun/wand to stock leaking. I pulled it apart and initially discovered a broken rubber o-ring. Easy fix? Yes should've been. Well, about 5 o-rings later of different sizes etc, I figured that there was something else wrong.

After further internet researching, I discovered a craftsman manual (basically identical pressure washer) and it showed an o-ring that would go next to a spring washer. This made sense since the gap (first picture) is too wide for just a standard #6 o-ring. But with a spring washer next to it, it would be the right size.

So my dilemma, I went to the hardware store and bought a #6 washer but the inside diameter is not wide enough to fit around this piece. I also could not find a metric #6 copper spring washer (just stainless). The washer needs to have the exact same diameters as the #6 o-ring or else it won't work. Any suggestions on exactly what I need to purchase? I want to make my next hardware store run a complete success. I have ace hardware and home depot at my disposal. Would the plumbing section have it's own copper hardware section with the copper spring washers? I'm at a loss.



washer.jpg

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Hiball

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Can you get by with using 2 orings back to back? Spring washers are mainly used to keep tension against a object, I believe a similar sized oring would prevent groove travel and provide tension and load shock.
 

crewchief888

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some of the big box stores sell pressure washer parts and accesories, i've definitely seem them at menards.




:beer:
 
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jjoel

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Can you get by with using 2 orings back to back? Spring washers are mainly used to keep tension against a object, I believe a similar sized oring would prevent groove travel and provide tension and load shock.

Tried the back-to-back o-rings and no such luck.


I spoke with a guy at "the helpful place" and he was pretty knowledgeable. I guess I'm missing the support or backup washer (can't remember what it's called) but it would be made out of plastic and is very common in hydraulics. So my search continues.
 

Hiball

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Tried the back-to-back o-rings and no such luck.


I spoke with a guy at "the helpful place" and he was pretty knowledgeable. I guess I'm missing the support or backup washer (can't remember what it's called) but it would be made out of plastic and is very common in hydraulics. So my search continues.

Backups are common in gland applications and aid in keeping extrusion under control, but based off the picture you would still need to take up some of that slack.

Maybe contact Fatfillup as he is a member and services pumps.
 
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EDGAR

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Aug 21, 2010
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The o-ring outside diameter should be slightly bigger than the diameter of the metal part in front of it so there is some squeeze of the o ring against the other part ( "the cylinder") where this parts enter. From the picture is difficult to figure if the o-ring OD would be slightly bigger or if it would be just level with the metal part in front of it. If it is level with the metal around it, it will not seal, even with a back up washer. Can you show a picture of the o-ring mounted?

Also, the backup washer has the same "part number" as the o-ring you use. And, as mentioned in another post, these are mostly nylon or PTFE.

For example, if you use an OR 114, the backup would be BU 114. The 114 number is called the "dash number" in the hydraulic industry.

The 000 series of O-rings are 1/16" thick (Cross Section), the 100 series are 3/32" thick, the 200 series are 1/8" thick, etc.

So the OR 114 mentioned above would be: 5/8" ID x 13/16" OD x 3/32" CS.

If the gap is too wide, you may want to use two backup rings, one on each side. If you use only one, the O ring should be placed between the pressure source and the backup ring. Press.-->OR-->BU. The pressure should press the o-ring against the backup ring and the backup expands to prevent extrusion.
 

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EDGAR

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He tried two O-rings already, post #5. He said it did not work. Although, if the O-rings were the correct size it should have worked, but would not prevent extrusion of the O-rings that way:dunno:
 
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jjoel

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He tried two O-rings already, post #5. He said it did not work. Although, if the O-rings were the correct size it should have worked, but would not prevent extrusion of the O-rings that way:dunno:

I used two rubber o-rings. He's referring to the nylon backup o-rings.

This is the rubber o-ring that fits. It's slightly larger than the outside diameter of the metal piece. It actually seals just fine until the gun is cycled a couple times and it just splits the o-ring in half. Could someone recommend the exact backup ring that I should purchase? I'll probably purchase a couple just incase it doesn't take up the whole slack.

http://www.homedepot.com/p/DANCO-6-O-Rings-10-Pack-96723/202251690
 

Hiball

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I used two rubber o-rings. He's referring to the nylon backup o-rings.

This is the rubber o-ring that fits. It's slightly larger than the outside diameter of the metal piece. It actually seals just fine until the gun is cycled a couple times and it just splits the o-ring in half. Could someone recommend the exact backup ring that I should purchase? I'll probably purchase a couple just incase it doesn't take up the whole slack.

http://www.homedepot.com/p/DANCO-6-O-Rings-10-Pack-96723/202251690

-011 Is the linked oring size, so you will need a backup to fit a -011.

And that's for a 5/16" x 7/16" x 1/16 Cross Section Oring, Im having a hard time wrapping my head around that size versus your earlier picture. The Specifications on the Page you linked at the bottom don't match the upper Specs. :dunno:
 
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fatfillup

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Sorry I'm late to the party but cannot help. I don't even try to repair trigger guns as it is not cost effective for my customers.
 
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