O rings, not all the same

[SwampmanLA]

I had a leak on 422 and traced it down to the blocks under the tram pump. I figured something was cut, pinched, or otherwise defective so off I went tearing into the bottom of the tram connections. Well what I found was puzzling to me. Nothing looked damaged except for the O rings on the fittings. They were intact except for being harder than a new one and being flat in spots. So I changed out all the O rings on the connections and presto, no more leaks.

Well that got me to thinking, why had the O rings began to leak? So off to the Internet to learn about O rings. These were black in color so I guess they were nitrile and only good for 250 degs. I suppose the oil heated these fittings to at or above 250 degs and deformed the O rings. Now my questions to the group..........

Has anyone had a heat related O ring failure on Power Tracs? If so what kind of O ring material did you replace them with? What was the heat range of the new material?

Swampman

 

[SpringHollow]

O-rings on my articulating cylinders got hard and brittle, pieces missing even. They were "natural" (amberish white) in color. I replaced with the same kind - a rebuild kit from Power Trac.

Ken

 

[tommu56]

here is a good site to look ay the different types
O-Ring Material Selection and Design Guide

tom

 

[oldnslo]

O-rings will harden and take a set due to age and temperature changes. Viton is better for temperature extremes than Nitrile (Buna N) and usually readily available from any good O-ring supply house.

Depending on the types of fluids Viton has better chemical resistance that Nitrile also.

Amberish white could be teflon or Urethane.

Roy

 

[jaquetarr]

After Viton O Rings are in service at high temperatures they react and create a hazardous coating. We were instructed not to remove them with bare hands or to let them contact skin. Use nonporus nitrile gloves.
These were in service in Low Speed Diesel engines and were subject to high temperatures for extended times.
Don't know if the same conditions would develop on the PowerTrac.
Rgds,
tim

 

[Wayne County Hose]

I had a leak on 422 and traced it down to the blocks under the tram pump. I figured something was cut, pinched, or otherwise defective so off I went tearing into the bottom of the tram connections. Well what I found was puzzling to me. Nothing looked damaged except for the O rings on the fittings. They were intact except for being harder than a new one and being flat in spots. So I changed out all the O rings on the connections and presto, no more leaks.

Well that got me to thinking, why had the O rings began to leak? So off to the Internet to learn about O rings. These were black in color so I guess they were nitrile and only good for 250 degs. I suppose the oil heated these fittings to at or above 250 degs and deformed the O rings. Now my questions to the group..........

Has anyone had a heat related O ring failure on Power Tracs? If so what kind of O ring material did you replace them with? What was the heat range of the new material?

Swampman

Are you sure you used the correct o-rings? Usually, o-rings on fittings are 90 durometer, harder than the 70 durometer o-rings found in your typical assortment kit.

Are you sure you're exceeding 250 degrees? Most common hydraulic cylinder seals are only good for 212 degrees.

 

[SwampmanLA]

Are you sure you used the correct o-rings? Usually, o-rings on fittings are 90 durometer, harder than the 70 durometer o-rings found in your typical assortment kit.

Are you sure you're exceeding 250 degrees? Most common hydraulic cylinder seals are only good for 212 degrees.

The O-rings that I removed were factory and leaking. I just replaced them all with the 'kit' ones that fit the fittings. So far so good but I have not really worked them hard yet. Spring is getting closer and my wife has an entire landscape plan she expects will be implemented using the PT.

 

[SwampmanLA]

After Viton O Rings are in service at high temperatures they react and create a hazardous coating. We were instructed not to remove them with bare hands or to let them contact skin. Use nonporus nitrile gloves.
These were in service in Low Speed Diesel engines and were subject to high temperatures for extended times.
Don't know if the same conditions would develop on the PowerTrac.
Rgds,
tim

Thanks for the tip. If I have to go that route I'll glove up.

 

[J_J]

Thanks for the tip. If I have to go that route I'll glove up.

I really don't think there is, or will be a problem with the o-rings. Some of the o-rings have been around in the PT's as far back as 39 years. My Pt-1445 is an early 90's model. The safety article stated temps above 315 F. I doubt if the PT gets over 200 F. If you think the fluid gets hotter than that, pour some water on the side of the reservoir and see if it bubbles and or turn into steam. The normal temp for long term use for hyd fluid/oils, in about 180 to 200 degrees. Working with gloves is always a good thing. Used oils/fluid contains extra chemicals caused by heat, water, metal particles, etc, and could be hazardous.

http://www.edwardsvacuum.com/uploadedFiles/Resource/MSDS/P120-04-015D O-Rings-Viton.pdf

 

[SwampmanLA]

Had a hard weekend of Power-Tracing, spring is here and my wife needs some help with her hobby, building flower beds at new house. After moving about 50 yards of dirt, sand, and mulch, I find another leak from the blocks under the tram pump. I did not tear it down yet but I just tired of this thing leaking oil all over creation after just 14 hours since I changed the last set of o-rings. I'll let you know what I find.

From the Swamp