Oil Blow-by from the AC breather bolts.
Thread Starter
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Stellar HDF Member
Joined: Aug 2011
Posts: 3,158
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From: Martinsburg, WV
Oil Blow-by from the AC breather bolts.
Anyone deal with this? I installed an aftermarket AC with larger breather bolts and noticed my first time out, oil sitting on the bolts. I've read about this and hear it's a pretty common occurence with 95+ big twins especially when ran harder. I was riding pretty aggressive that day and figured that was the issue. So, the question is, what to do? Hydraulic oil pump and new cam plate help this out at all?
Grand HDF Member
Joined: Jun 2009
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From: On the Front Range, CO
Harley actually updated the breather assemblies, under the rocker box covers.
The new part number is 17025-03A.
They apparently work much better than the stockers, and even though they were introduced in 03, they weren't standard until 2011.
Some people will suggest running the oil level lower as well.
The new part number is 17025-03A.
They apparently work much better than the stockers, and even though they were introduced in 03, they weren't standard until 2011.
Some people will suggest running the oil level lower as well.
Thread Starter
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Stellar HDF Member
Joined: Aug 2011
Posts: 3,158
Likes: 68
From: Martinsburg, WV
Harley actually updated the breather assemblies, under the rocker box covers.
The new part number is 17025-03A.
They apparently work much better than the stockers, and even though they were introduced in 03, they weren't standard until 2011.
Some people will suggest running the oil level lower as well.
The new part number is 17025-03A.
They apparently work much better than the stockers, and even though they were introduced in 03, they weren't standard until 2011.
Some people will suggest running the oil level lower as well.
Tourer
Joined: Dec 2012
Posts: 274
Likes: 0
From: Illinois
Not hard at all.
Remove the the tank and rocker box covers.
The breathers are right under there in the middle of the two rocker arms.
Should be two 3/8" bolts.
change them out for the new metal assembly's.
There not expensive either.
Remove the the tank and rocker box covers.
The breathers are right under there in the middle of the two rocker arms.
Should be two 3/8" bolts.
change them out for the new metal assembly's.
There not expensive either.
Grand HDF Member
Joined: Jun 2009
Posts: 4,002
Likes: 1,240
From: On the Front Range, CO
Just make sure to get new gaskets for the rocker boxes.
If you are pulling the the lower rocker boxes too, you'll need to make sure the cylinder is on the base circle of the cam shaft to remove the rocker assemblies. Basically, base circle means the valves are closed and the pushrods have no tension on them. With the rocker covers off, this is easy to see. Must be done for each cylinder too.
You can turn the engine by being in 5th gear and spinning the back wheel.
Last edited by Redbeard719; Mar 13, 2013 at 10:31 AM.
Seasoned HDF Member
Joined: Mar 2010
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From: Honah Lee
Anyone deal with this? I installed an aftermarket AC with larger breather bolts and noticed my first time out, oil sitting on the bolts. I've read about this and hear it's a pretty common occurence with 95+ big twins especially when ran harder. I was riding pretty aggressive that day and figured that was the issue. So, the question is, what to do? Hydraulic oil pump and new cam plate help this out at all?
Thread Starter
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Stellar HDF Member
Joined: Aug 2011
Posts: 3,158
Likes: 68
From: Martinsburg, WV
Little curious why you say you have oil on the bolts. I assume you are talking the bolts at the valve covers and not the filter cover bolts. With an open filter you are going to get a few drips from bottom of filter down on the cam covers especially if you let the bike sit for a few week and then run at speed in the 4000 rpm range. If it's the top bolts, sure you did gasket or o-rings correctly?
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I have the newer breather assemblies in both of my 2002 95" builds and one still blows plenty of oil. The other has a Pm assembly that comes with rubber boots for teh end of teh breather bolts that directs the blow by back into the intake. So what I am saying is that there is no guarantee that the newer breathers will fix the issue although they are definitely "new" and improved compared to the older ones.
Before replacing the umbrella valves, check out this thread-
https://www.hdforums.com/forum/oil-r...oil-level.html
If you are running the correct weight oil, at the correct level, per HD spec in above link, then I would look next to the umbrella valves.
https://www.hdforums.com/forum/oil-r...oil-level.html
If you are running the correct weight oil, at the correct level, per HD spec in above link, then I would look next to the umbrella valves.
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