Blown head gasket
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Road Captain
Joined: May 2011
Posts: 684
Likes: 9
From: Indian Head, PA
Blown head gasket
Just picked up my bike from the shop after having a new rear tire installed, and noticed that the chirpy-crack noise my bike has always made since I bought it seemed a lot worse. I noticed a puff of hot air on the back of my right leg in time with the engine, followed it to it's source and discovered it was coming from the rear cylinder's head gasket. As of yet, I don't know if it's just loose head bolts or if the gasket is blown out and needs replaced.
I just started tearing into it, since I definately don't have the money to pay the shop to do it. I have the seat off and almost have the tank off. Can I get the rocker covers and heads off without having to pull the engine out of the bike? Also it looks like I need a special socket for the head bolts that I don't have, any idea in advance what that is going to cost me?
I made my own work stand for the bike with a pair of jack stands under the passenger floorboard mounts. Holds the bike vertical and rock solid to boot. Sure beats having to go buy a bike lift/stand!
Anyone have any useful insight and or wisdom they could share with me? This is the first time I've torn into a Harley, but I'm not afraid of wrenching and have a decent set of tools... And no, I don't have the shop manual... yet. I will be picking one up soon, I'm sure!
I just started tearing into it, since I definately don't have the money to pay the shop to do it. I have the seat off and almost have the tank off. Can I get the rocker covers and heads off without having to pull the engine out of the bike? Also it looks like I need a special socket for the head bolts that I don't have, any idea in advance what that is going to cost me?
I made my own work stand for the bike with a pair of jack stands under the passenger floorboard mounts. Holds the bike vertical and rock solid to boot. Sure beats having to go buy a bike lift/stand!
Anyone have any useful insight and or wisdom they could share with me? This is the first time I've torn into a Harley, but I'm not afraid of wrenching and have a decent set of tools... And no, I don't have the shop manual... yet. I will be picking one up soon, I'm sure!
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,293
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From: Honah Lee
My Softail has allen cap screw in the valve cover bolt so you can take a cutoff wrench to allow better access. I think the head bolts take a 12 point regular socket. Most sets do not come in 12 point when they get that big. Of course much smaller but the bolts that hold the caliper are 12 point. Guess Harley figured the looked a little more professional that way. Some bolts on a Harley are pretty cruddy looking. You positive it's not the rear exhaust header leaking. Seen those two bolt tight but pipe actually not down on the copper crush gasket because someone did not replace them
Last edited by Jackie Paper; Jul 28, 2011 at 07:38 PM.
Outstanding HDF Member
Joined: Nov 2010
Posts: 2,627
Likes: 3
From: S.E. Va
You might need a special tool to get the rear rocker box off (spring compresser) is it the head or rocker box gasket? I don't mean to be stupid just asking. If you have a shop manual it will tell you and if you don't have one get one, there are some tools you can make and others go to ebay. One thing you need to know is when putting the rocker boxes back on you need to bleed the lifters and there is a certain way to pull them off and reset them. I am not at home and don't have my manual so I can't give you more info on it. Sorry and best off luck with it.
I should be home friday night and I'll check your thread again and if you need me to I'll send you the link to where I have bought tools from.
I should be home friday night and I'll check your thread again and if you need me to I'll send you the link to where I have bought tools from.
Thread Starter
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Road Captain
Joined: May 2011
Posts: 684
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From: Indian Head, PA
It is definately the head gasket, not the rocker box...
Road Master
Joined: Sep 2006
Posts: 1,121
Likes: 6
From: Huntersville, NC
you'll need to cut down an allen wrench to get those back bolts off the rocker box. pretty straight forward job after you get the box off. Don't pull on the jug after you unbolt the head and you should be ok. Worked for me years ago and it didnt disturb the base gasket.
Thread Starter
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Road Captain
Joined: May 2011
Posts: 684
Likes: 9
From: Indian Head, PA
Can I get away with only doing the rear head gasket or should I go ahead and replace both while I have the tank off?
I have never seen the inside of the rocker box before. My initial intentions were to just pull the rocker covers and see if perhaps the head bolts were loose before actually disassembling and replacing the head gaskets. Judging by the size of the leak, however, I'm pretty sure I will need to replace the gaskets.
Is there a gasket between the head and rocker box? How about the rocker cover? Should I get new ones for there as well? Any and all help is very much appreciated.
I have never seen the inside of the rocker box before. My initial intentions were to just pull the rocker covers and see if perhaps the head bolts were loose before actually disassembling and replacing the head gaskets. Judging by the size of the leak, however, I'm pretty sure I will need to replace the gaskets.
Is there a gasket between the head and rocker box? How about the rocker cover? Should I get new ones for there as well? Any and all help is very much appreciated.
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Seasoned HDF Member
Joined: Mar 2010
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From: Honah Lee
Just replaced a head gasket on a Z28 Al head that was taking so much water it killed the cat, locked up a cylinder and broke off the starter nose when cranked due to hydraulic lock. It had 100K and leak developed from just a slight heat expansion overtime. Head and block looked good. You say you are seeing a flash between head and cylinder. Last time I saw that was in the 60's on my wizzer motorbike. Give it a try but if it was me I would at least since you are in this far pull both heads and check valve for leaks . Probably ought to check compression before pulling heads to see what they are and if front looked good maybe it's ok. Usually rear goes away first. Hay, depends on what you want. I do not go far with mine, so long as it runs I'm fine. Mine sound like a rotary tiller in a gravel bed.
Last edited by Jackie Paper; Jul 29, 2011 at 12:03 AM.
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Joined: Dec 2009
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From: navarre ohio
if it ran with the headbolts loose the gasket is blown anyway..you should replace both head gaskets at the same time...while it is apart its a good time to have the heads cleaned up and checked at a automotive machine shop(napa) new rings and have the cylinders honed,its not much money will only take a couple hours, and you will basically have a brand new top end for under a couple hundred bucks.i just bought a james fire ring complete top end gasket kit last month,it cost $50.no worrys for a long time
Road Warrior
Joined: Jun 2009
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From: SoCal & West TN
I had the exact same thing happen to my 1989 Ultra. Be sure not to start it with it blowing air out. It will melt the head or cylinder and you will not ever get a good seal.
I replaced just the rear gasket. I took the head off and made sure not to move the cylinder. That way I didn't need to reseal the bottom of the cylinder. But I also used new head kept nuts when I reinstalled the heads. The old ones were loose and I didn't trust them to be torqued to the proper tension.
I also used a copper gasket and anti seize.
I replaced just the rear gasket. I took the head off and made sure not to move the cylinder. That way I didn't need to reseal the bottom of the cylinder. But I also used new head kept nuts when I reinstalled the heads. The old ones were loose and I didn't trust them to be torqued to the proper tension.
I also used a copper gasket and anti seize.