Hi all,
Well, in looking over the engine while I have things apart, I noticed that I have some leakage going on around the PCV valve grommet area on the front cylinder. So, looks like I'll be replacing that. Fortunately, I already have the engine primed for rotation since I'm working on my exhaust header, so rotating it back down again is no big deal. And, they actually had the PCV valve and grommet in stock at my local Harley dealer.I figure I'll replace both the valve and the grommet just to be safe since I don't want to have to do another engine rotate once I get it all put back together. So, along those lines, is there anything I should do to try and keep this leak from returning? I've done some searches and a few folks have suggested using yamabond to seal the PCV valve to the grommet. Any thoughts?
Thanks!
Will do. I went ahead and replaced the valve and grommet. Didn't do anything special, just replaced old with new. Hopefully that will take care of the problem Just makes me nervous that the bike only had 6000 miles on it and already needed the grommet replaced. But, in looking at, it's not surprising since there is no o-ring or anything that really makes a good seal between the grommet and the valve stem, which itself is just a plastic piece.
It's also interesting that I can't find any reference in the manual to replacing the PCV valves and grommets. I guess it is supposed to be obvious that you need to rotate the engine to replace the front one? Or it was thought they would never need replacing?
^^^what he said.I can't think of any other tips for replacing them. Maybe a thorough cleaning versus replacing the valves themselves? I could see replacing the grommets to ensure the cleaned up valve seats nice and snug. My bike is in tear down stage. So, I assumed why not replace the pcv valves and grommets since I'm doing plugs, wires, and coil. Plus, after installing new headers, I noticed the front cylinder upper rocker box gasket needs to be replaced. It sucks that I have so many things that need maintenance at one time that I wasn't anticipating. But, good thing to address them sooner than later, and all at once instead of having to tear the bike down multiple times. Every time I open the shop door it saddens me to see her in this state for this longMake sure your zip ties are good and tight, I had the same issue with my 09, I did a breather reroute with new hoses and made sure everything was tight, I didn't replace the valves.and it takes forever to get parts delivered........the joys of working on a Buell. BUT, worth every second when I'm scooting around on her!!!! I love the head turns when I roll off the throttle or blip it at stop lights
alot of chatter on the board this month regarding XB breather systems and an inference however slight....that there are inherent problems with the design and the "top end" components. wrong on all fronts. if there is a leak in the vent area atop the rocker lids it's typically owner induced or uneducated fiddling. and by that i mean: an XB repeatedly subjected to extraordinarily high temps will substantially harden and weaken the grommet assemblies. an XB repeatedly subjected to motor oil over-fills will tend to "mist" oil out of the grommet/valve area giving the appearance there's a problem with the lid parts. an XB on which an improper breather re-route has been performed by an amateur plumber will always leak oil. an XB with stock breather plumbing that has been fiddled with tends to have the valves NOT seated correctly into the grommets causing leaks.
This is what I used when I replaced my grommets: Permatex High Tack Gasket Sealant #80062. It's intended for gaskets but works just as well for this application. 1,700 miles so far with not even the hint of a leak.
Apply it thoroughly to the grommet ring circumference before inserting in the head. Then apply to the outside of the pcv valve on any surface that will touch the grommet before insertion.
Probably won't work very well on old, worn out grommets that fit loosely in the hole.
Permatex_High_Tack_Sealant.jpg
I was tempted to use sealant as well, ReadyXB. In the end, I just went with using new parts in the plain stock configuration. I'd be interested in hearing how yours is longterm. You certainly shouldn't have to worry about leaks.
John...I certainly don't know the history of my breather system other than the PO did to the re-route. As you say, that is probably where the trouble started. As far as design, I'm no expert....so I can't really say how good or bad it is for the application. It seems like there would be more sure ways to create a seal...but maybe that was intentional for other reasons when designed. I mostly find it strange that there is no mention that I can see in the shop manual about how to remove/install...pretty much every other part of the bike is in there somewhere.
Thanks again for the discussion everyone! I'm hoping to complete this project in the next couple of weeks as time allows! Now I just install a time-sert (found that out when I started this) and install the new muffler/ecm. It's slowly coming back together!
Anyone have a part number for those pcv grommets?
Last edited by Silverrider; 12-09-2016 at 05:58 PM.
Posting Permissions
Reply With Quote