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Leaky Rocker Box

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  #1  
Old 10-11-2007, 08:49 AM
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Default Leaky Rocker Box

I just got done having to replace the cylinder base gaskets. Got it all bolted back together and the front upper rocker box had a small oil leak. I noticed, the covers were not spaced evenly....so I loosened the bolts and realigned everything. Tightened it back down and it was still leaking. The leak was at the left corner of the rocker box.

Removed the rocker boxes and installed new gaskets. Unfortunately, it leaked in the same place; however it seemed not as bad.

I used the torque wrench on all the bolts, except two of them. The only two that were totally inacessible for use with a torque wrench. I layed the covers on a flat glass table and they appeared nonwarped. The covers are OEM stock Harley parts that came with the bike. I put just a little automotive grease on the gaskets to help keep them in place during the installment.

I've done these repairs many times before and never with this such bad luck. Any ideas just short of replacing the cover/s? Thanks
 
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Old 10-11-2007, 09:16 AM
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Default RE: Leaky Rocker Box

Wipe the grease off of them and tighten them just a little tighter . I have always use oil or grease on an o-ring but every time I do it to a rockerbox it leaks every time .
 
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Old 10-11-2007, 10:04 AM
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Default RE: Leaky Rocker Box

I like to use the metal gaskets with the silicone on them. Also, try coating the gaskets with a thin layer of Aviation Gasket stuff from NAPA.

Last time I tried to use a torque wrench on a rocker box, I snapped a bolt off. I had to pull the head to get the thing out. Won't do that again. Back to "feel" for me.
 
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Old 10-11-2007, 01:21 PM
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Default RE: Leaky Rocker Box

I had the same problem this spring after last winter rebuild. I used Jims gasket set. After the leak started I removed the new gaskets and used oem from dealer, it's been good all summer. Note: Even though mine looked flat, I still ran them over some ruff sand paper just for fun. It didn't remove any real material, just some of the chrome from the fins.
 
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Old 10-11-2007, 02:31 PM
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Default RE: Leaky Rocker Box

I might try tightening that one bolt where the leak is occuring......before going further. I might have over done it on the grease though....so perhaps the grease got hot and then turned into oil? I think I may ride it tomorrow for several miles to get the motor all nice and hot....this will eliminate my theory of the grease turning into oil. Aviation Gasket sounds like a good idea, the local airplane mechanic uses the stuff frequently.

If that fails to cure the problem.....damn things are coming off again![:@]
 
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Old 10-12-2007, 08:11 AM
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Default RE: Leaky Rocker Box

ORIGINAL: EVOrider...Aviation Gasket sounds like a good idea, the local airplane mechanic uses the stuff frequently...
[:'(]

Trust me on this. I had my 93 EVO's rockerboxes resealed eight times. One of the last times I let an Indy do it (they'd done the work before they started leaking), they gooped it all up with Aviation Gasket sealer. That stuff is a Biotch to remove, especially in the tight confines of the sealing surfaces. If youfeel that you want to use something I'd recommend Hylomar.

My problem was that I had warped covers. The Indy shop put on chrome aftermarket onesto replace my ratty lookingnon-chrome ones(they were supposed to me Genuine HD parts). I could run the motor, andhear/feel the air blowing out from the rockerboxes. I swapped in the Genie parts...No leaks.IIRC, a complete set (you have to buy each piece individually) runs around $600.

Are the umbrella valves in the correct location? They should be on the intake side of the motor, not the exhaust side. Try tightening the cover again, you could be just seeping that liquid grease out of the seam. Also, have you ascertained where it's leaking?Run the motor, andmove your hand/finger around the rockerbox seams.Trust me, if it's leaking badenough, you'll feel the air pulsing.

I don't use anything on the gaskets. Get everything good and clean,and tighten the bolts in a 'cross pattern'. If you don't have the 'special wrench' that is available to get at those couple bolts, I use a small allen wrench that I've cut off to fit. I use the'two finger' torque method, and re-tighten them after I've run the motor to operating temp. Take the bike out on the highway. 70 mph for 10-15minutes. If it's gonna leak, this is when it will show up. The oiling system on the EVO pumps most of the oil into the rocker boxes at that rpm, so in additon to the pressure that is present you have a large amount of oil to contend with.

If this fails to stop the leak, you'llneed to recheck those rocker boxes. Normally, it's the middle one that goes to hell.But you won't know until you check them. The glass table method works, but use a thin feeler gauge to see is there is any variances around the edges.
 
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Old 10-12-2007, 08:18 AM
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Default RE: Leaky Rocker Box

Yup........what HACKD said.....happens all the time.....
 
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Old 10-12-2007, 08:23 AM
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Default RE: Leaky Rocker Box

I have my rear right side back corner leaking right now.
I have a 2002 electraglide and it's just leaving a little oil stain
now but I guess I'll attack it this winter. I had a sportster
and I waited till my wife started getting a oily leg when I finally
replaced them. Did not have a problem after that. I'll have
to check what we used to replace them. It was a after market gasket set.
 
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Old 10-12-2007, 08:33 AM
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Default RE: Leaky Rocker Box

I took about a 20 minute ride today.....however, before the ride; I wiped the covers with a white napkin. I continued wiping it until absolutely no trace of oil/grease appeared on the napkin.

After the ride......I found no trace of oil/grease on the covers. My wife and I are planning on riding tormorrow for the full day......so that will be a good test to see if its gonna leak or not.

Thanks for everyones ideas, it was much appreciated.....

I'll let you all know tomorrow evening after the long ride.....
 
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Old 10-12-2007, 01:04 PM
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Default RE: Leaky Rocker Box

i had the same problem. i used permatex ultra grey. coated the o-ring and all surfaces, let it sit up for 30 minutes and installed them, no leaks.
 


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