Parts Question
Oil Tank leak thru Vent Question.
Hello, and First of...
Parts Question posted December 15, 2015 by Jim Rodgers, last edited December 15, 2015
1322 Views, 2 Comments
Question:
Oil Tank leak thru Vent Question.
Hello, and First of all....if you are reading this, thank you for trying to help.
I have a Sweden made, early 1990's 394XP chain saw. I love this saw, however I am fighting a bar lube oil tank leak and references are few and far between for this obsoleted unit.
My belief is that the bar chain oil is coming out of the end of the oil tank vent tube. I know this is happening, as when I remove the bar, start the engine, and at off idle RPM I can watch oil come out of the end of the vent tube itself.
I pulled the vent line (P/N 501839302) out of the saw itself. In the end of my tube (bar stud side), there is simply a standard hollow roll pin stuck in the ID of the tube. This means there is a clear passage from the oil cap all the way thru the tank to the bar studs.
My question is....Is this hollow roll pin the correct part for this application? Past experience proves that most saw vents have what I would call a "threaded set screw".
I have obviously tried to order a new vent line for replacement, however no dealer and not website I have found yet offers this OE replacement.
Thank you again for your help.
Jim
Hello, and First of all....if you are reading this, thank you for trying to help.
I have a Sweden made, early 1990's 394XP chain saw. I love this saw, however I am fighting a bar lube oil tank leak and references are few and far between for this obsoleted unit.
My belief is that the bar chain oil is coming out of the end of the oil tank vent tube. I know this is happening, as when I remove the bar, start the engine, and at off idle RPM I can watch oil come out of the end of the vent tube itself.
I pulled the vent line (P/N 501839302) out of the saw itself. In the end of my tube (bar stud side), there is simply a standard hollow roll pin stuck in the ID of the tube. This means there is a clear passage from the oil cap all the way thru the tank to the bar studs.
My question is....Is this hollow roll pin the correct part for this application? Past experience proves that most saw vents have what I would call a "threaded set screw".
I have obviously tried to order a new vent line for replacement, however no dealer and not website I have found yet offers this OE replacement.
Thank you again for your help.
Jim
Photo:
Answer
Don't know the answer to what was used in the tube as I haven't worked on any of these but I think PN 503 66 84-04 is the current replacement part number which is used on the later versions of the 394. I thinking as this is the case as the complete crankcase part number is only show revision level change from 503 46 80-01 to 503 46 80-02
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Jim.
I am not familiar with older Model 394, but I think I have seen that on another older brand and different manufacture chainsaw, (Maybe a Poulan). Anyhow the science behind using the roll pin is good, and that is simply to reduce the vent size so the viscosity or thickness of the oil wont drip out of the vent but will allow air into the tank. And since Air has a almost No viscosity it will easily go into the tank thru the roll pin. Its kind of like the old glass ketchup bottle, where the neck size is greatly reduced, and If the ketchup has a thick viscosity when you turn the bottle upside down the ketchup won't come out. Anyhow, I don't know for sure but I believe the roll pin is the correct part.
Now, back to your problem, I suspect its a viscosity or pressure problem, If the newer bar chain oil is a lighter thickness, then the roll pin can no longer work, they do make different viscosity bar chain oils, even some very lite oils used for winter use only since the oil naturally gets thicker when its cold, so check that your using the correct bar chain oil.
Next, Is there any possibility that the bar chain oil is getting heated a little by say a Hot exhaust muffler, this would definitely thin the oil, Or does the Oil start to come out the vent even without the chainsaw running ?
Also, It could be a pressure problem if the bar chain oil tank is building up pressure some how, but I can't imagine how. Oh, I have seen the threaded set screw and they work on the same principle to let air in, and keep the liquid from coming out but have seen those types on fuel tank vents, and obviously the viscosity of fuel is much much lighter than oil, and that's why the set screw type is used.
I hope the information helps, and I realize that it does Not directly answer your question.
Karla
PS. I am Not a Husqvarna Representative or Repair Service, just an experimental chainsaw person.
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