Replacing head gasket best practices

[Jim L.]

Requesting your thoughts on replacing head gaskets.

My machine an L3800, slight pressure build in radiator, no coolant in oil, or oil in coolant. I'm thinking a small leak in head gasket. Looked at bubbles in radiator but frothes and can't really tell.

I have the WSM and parts manual. Understand that I will have to match the existing gasket. Understand torque sequence. Understand replace heat disks around injectors.

a) Sealant spray or no sealant spray on gasket?

b) Reuse bolts or get new ones?

c) Thread sealant or crush washers needed?

d) Anything else not in the book but good to do?

Thanks, gents, for the advice.

 

[Tooljunkie]

My preference is to follow workshop manual procedures. Head bolt replacenent usually applies to torque to yield bolts that requires bolt stretch as part if the sealing process. Common on automotive applications that use aluminum heads and multi layer gaskets.
Head bolts can be checked for corrosion visually and inspected with a straight edge for stretch-they will show signs of necking or a narrow part.

Sealant such as copper coat are common in old engines that used a single layer gasket similar to those used in a flat head engine.

Bolt sealants usually apply to threaded holes in block that go into the water jacket. Most anti sieze compounds also serve as a bolt sealant.

Wet or lubricated bolts torque differently than dry bolts. Be sure you are aware of this when torquing head bolts.manual reccomendations apply here.

Using these theories may help when no repair manual is available, like when working on a 1927 studebaker where access to a repai manual is out of the question- i do have a manual,there are no torque specs for any assembly on that car.

 

[North Idaho Wolfman]

a) Sealant spray or no sealant spray on gasket?

No not on the head gasket, just make sure everything is clean and dry.

b) Reuse bolts or get new ones?

Reuse is fine if there is no damage to the bolts.
Hopefully you have kept the bolts in the same holes if apart or if not apart yet do that.

c) Thread sealant or crush washers needed?

Nope does not appear so.

d) Anything else not in the book but good to do?

Have an adult beverage of choice when the job is done!

 

[Jim L.]

Wolfman, ToolJunkie, thanks for the good advice.

The little orange machines have worked so well that I have never had to open one up!