# Can't get yanmar valve cover off-Yanmar YM3000



## Robert Rowley (Oct 20, 2019)

Yeah, I know, how pitiful is this?! I've hammered on the thing with a rubber mallet, a big ball peen hammer with a 2x4 under it, etc., etc. I've pried on it with a crow bar. I don't to get too violent with it, I don't want to break anything. The cover has not been off since I bought it reconditioned in 2005. Is there something I'm missing here??


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## winston (Aug 19, 2008)

Thinking you have 3 bolts going through the top of the cover. With those out and it still stubborn I would surmise someone used a good silicone on the o-ring type gasket. Might have to replace the gasket but knowing what you have already tried I would approach with a very thin scraper (puddy knife) and drive it in between the head and cover.


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## bmaverick (Feb 20, 2014)

There are parts for that engine being a 3T84. Once it's off, order a good gasket for it. One that can come off EZ vs. the struggles you are having now.


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## Robert Rowley (Oct 20, 2019)

OK, thanks for the input. I'm attacking it today. Got a new gasket on the way. Are there any locating pins/dowels I need to look out for? I'm going to have to drive a putty knife or something around the whole thing it looks like. Looks like it's glued down pretty good with some kind of form-a-gasket goo that's now like a rock.


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## Bob Driver (Nov 1, 2017)

Heat gun/hair dryer around the gasket area for a few minutes. Man I hate that black Permatex... It won't leak, but it won't come apart either


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## winston (Aug 19, 2008)

I don't think any dowels but not positive.


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## Robert Rowley (Oct 20, 2019)

I give up.! I've ruined 2 putty knives, heated the thing with a heat gun and finally a propane torch, and pounded on it lots more. It ain't coming off. I was going to finally check the valves but I don't think they're off enough to warrant a new valve cover. I really think I'd have to break the thing to get it off.


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## winston (Aug 19, 2008)

Wow!


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## bmaverick (Feb 20, 2014)

Bob Driver said:


> Heat gun/hair dryer around the gasket area for a few minutes. Man I hate that black Permatex... It won't leak, but it won't come apart either


Welcome to our Yanmar forum. It would be great to see your pix of your YM3000 machine. 

http://www.tractordata.com/farm-tractors/002/4/4/2444-yanmar-ym3000.html


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## Bob Driver (Nov 1, 2017)

Sometimes you just hit the bottom of your "bag of tricks" and have to give up. Here's the last thing in my bag that I once used when somebody thought JB Weld would be a good gasket sealer for a rocker cover. Windshield Seal Removal Tool.... $17 at Wally world

https://www.walmart.com/ip/WINDSHIELD-REMOVING-TOOL/517049877?wmlspartner=wmtlabs&adid=22222222222159313532&wmlspartner=wmtlabs&wl0=e&wl1=o&wl2=c&wl3=75179178172081&wl4=pla-4578778748109742&wl5=&wl6=&wl7=& wl10=Walmart&wl12=517049877_10000017068&wl14=windshield tool&veh=sem&msclkid=1c6cfa72e6431d03a1eaa7cb7805fc58










Heat the tip a little with that propane torch, but not so hot it glows. Start by heating at a *corner* and try to *slowly *work the hot pointed tip through. You can tap lightly on the tip to help get it through the gasket material. Working across a corner first will allow the tip to get "behind" the gasket/sealer quicker. You're literally going to have use the tip of the tool to pick, poke, and scrape through the gasket/sealer to get a place started. Once you're through in an area, it starts to get much easier to pull the hot tip through the rest of the mess. Wedging a flat screwdriver behind the tool in area where you're worked through applies upward pressure that helps to separate the material as you pull the tool. That's it.... That's all I got left. Good luck


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## pogobill (Jan 31, 2012)

Sounds like a good idea Bob. I was thinking that a plastic wedge that tree fellers use could get tapped in and not mark the metal, as well... once you get the gap started.


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## Bob Driver (Nov 1, 2017)

Just to move the discussion towards the correct gasket sealers.... The best gasket sealers I've come across over the years to both seal and be able to disassemble later are anaerobic sealers. Permatex 51813 and Loctite 515. Both of these seem to be pricey at first to the DIY guy, but you put these on with a bead no bigger than a pencil lead. I've had a 50ml tube of 51813 that has lasted for over 10 years and I use it a lot. Kohler doesn't use pan gaskets on a lot of their engines any more. They use Loctite 30509. Really good stuff, once again seems pricey, but for a guy like me I can't afford a "comeback" for an oil leak. Never had a leak with any of this anaerobic stuff and it comes apart without the use of a jackhammer like the old school Black Permatex. I also hate it when I come across something where somebody has used RV sealer and put it on like they were icing a cake...


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