Base gasket weeping
Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
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From: Haslet Texas
BTW just because you are replacing base gaskets doesn't automatically mean you have to replace the studs/bolts.
Stellar HDF Member
Joined: Jul 2011
Posts: 2,583
Likes: 115
From: Boston, MA
On many heads this is 100% true to having to replace the head bolts, cars with aluminum heads anyways. You'll never get a true torque reading from re-using the head bolts. The do in fact stretch with thousands of heat cycles if you start the car twice a day and it is 5 years old. I have not replaced a head gasket on a car since a 1990s Ford Taurus so my experience is admittedly low........
Just what I've heard through the grapevine.
Just what I've heard through the grapevine.
Sponsor
Joined: Dec 2007
Posts: 12,084
Likes: 829
Good advice from Uncle Larry.
I'll add by saying that the Evo cylinder bases many times need to be machined to establish a precision gasket sealing surface and the primary side of the rear cylinder being the biggest offender.
Here, we accomplish that to the point that the cylinder bore ID, is EXACTLY 90* perpendicular to the cylinder bases once completed.
With a good Cometic gasket set, and torqued to 42 ft/lbs as per them, they stay leak-free.
Scott
I'll add by saying that the Evo cylinder bases many times need to be machined to establish a precision gasket sealing surface and the primary side of the rear cylinder being the biggest offender.
Here, we accomplish that to the point that the cylinder bore ID, is EXACTLY 90* perpendicular to the cylinder bases once completed.
With a good Cometic gasket set, and torqued to 42 ft/lbs as per them, they stay leak-free.
Scott
Seasoned HDF Member
Joined: May 2008
Posts: 21,146
Likes: 12,713
From: South Carolina
Many people think that because a fastener is torqued, and then turned a certain amount of degrees, that it is a Torque to Yield part that can only be used once...not true.
A lot of reusable fasteners are installed using this process, because it is the most accurate way of determining actual fastener tension.
The only way to know if the fastener is a Torque to Yield and cannot be re used is by the service manual.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,474
Likes: 57,028
From: Michigan 15 Minutes East Of Hell
Just some info about torquing and degreeing fasteners.
Many people think that because a fastener is torqued, and then turned a certain amount of degrees, that it is a Torque to Yield part that can only be used once...not true.
A lot of reusable fasteners are installed using this process, because it is the most accurate way of determining actual fastener tension.
The only way to know if the fastener is a Torque to Yield and cannot be re used is by the service manual.
Many people think that because a fastener is torqued, and then turned a certain amount of degrees, that it is a Torque to Yield part that can only be used once...not true.
A lot of reusable fasteners are installed using this process, because it is the most accurate way of determining actual fastener tension.
The only way to know if the fastener is a Torque to Yield and cannot be re used is by the service manual.
Seasoned HDF Member
Joined: May 2008
Posts: 21,146
Likes: 12,713
From: South Carolina
I was just pointing out to any that may not know, that the only way to determine that the fastener is actually a TTY part is by the service manual, not by the process used to torque the fastener.
Last edited by Dan89FLSTC; Dec 29, 2014 at 10:06 AM.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,474
Likes: 57,028
From: Michigan 15 Minutes East Of Hell
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Stellar HDF Member
Joined: May 2009
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From: Middle of Kansas
I have 47,000 on my EVO with nary a leak and has never been apart. Mine did start to seep one time when I changed to Mobil 1 V twin synthetic oil. I only ran it 1,000 miles and changed it back to Castrol GTX 20-50. It quit seeping right away. I also let it warm up until the rocker boxes are getting warm. If mine was just seeping I would not do anything to it until it started actually leaking a puddle. But, that is just me. If it aint broke don't fixit. Evo's can run 150,000 miles if taken care of without taking them apart.
Last edited by Jim Kraft; Dec 29, 2014 at 10:09 AM.
Road Master
Joined: Jan 2012
Posts: 856
Likes: 9
From: North Carolina
If the base gaskets are weeping then it's easy to replace them. If you have a good set of tools THAT YOU KNOW HOW TO USE and a good torque wrench it's a two day job. Pull, the tank, rocker boxes, rockers, push rods (remember how they go back), heads, and the slide the cylinders up till you see the wrist pin circlips. Pull one side, slide the pin out till the piston comes off of the rod. Inspect the inside of the cylinders for cross hatching. Make sure the pistons and valves look good. Shove clean rags down in the spigot holes to keep junk out.
The hardest part is scraping gaskets without damaging the aluminum cases and cylinders. Soak the female head bolts in motor oil. Get some Genuine James gaskets and reassemble using all new O-rings and gaskets. Use new wrist pin circlips. Torque the head bolts exactly as the book says. Instal the push-rod tubes in the order they came out. You're back in business.
I have a buddy with 260,000 miles on his old EVO, FLH. He has done this job a half dozen times since 1986. He has never had the cylinders or heads reworked and is still one the original pistons and rings. His bike is stage one, stock cams, etc.. I did this job on my old Heritage two years ago it took me about 16 hours total. But, I took my time and was super careful scraping gaskets.
The hardest part is scraping gaskets without damaging the aluminum cases and cylinders. Soak the female head bolts in motor oil. Get some Genuine James gaskets and reassemble using all new O-rings and gaskets. Use new wrist pin circlips. Torque the head bolts exactly as the book says. Instal the push-rod tubes in the order they came out. You're back in business.
I have a buddy with 260,000 miles on his old EVO, FLH. He has done this job a half dozen times since 1986. He has never had the cylinders or heads reworked and is still one the original pistons and rings. His bike is stage one, stock cams, etc.. I did this job on my old Heritage two years ago it took me about 16 hours total. But, I took my time and was super careful scraping gaskets.