Gaskets & O-Rings

[Cougar281]

What gaskets Absolutely Cannot be re-used on the Duramax, besides the Headgaskets (duh) and the injector O-rings (since they usually break on removal)? I've just put a new water pump gasket (the one to the tube that connects the oil cooler), and the two for the coolant crossover. They will have a few weeks of use, at most, when I pull the motor out and swap things around. I reused most of the O-rings (hopefully it won't come back and bite me). If I can avoid replacing them again, without too much fear of leaks, I'd like to.

Obviously, to swap the heads, I'll need headgaskets & bolts. Any others that I NEED to get? I'll probably pull the injectors and clean them up, so I'll also need an injector sealing kit.

Edit: On the subject of gaskets, I've read several places (not Duramax Specific) that some recommend using some kind of gasket dressing such as this. I've never heard of doing this. I just used "dry" felpro gaskets on the 4.6 in my Cougar and haven't had a lick of trouble. Thoughts on these "sealants"?

Does anyone see any issue using these to clean the block and head surfaces?

 

[bullfrogjohnson]

Most of the o-rings can be reused. It all depends on how the o-rings look. If any of them look flat and not round anymore I would recommend changing them. Everything else is rtv or a metal gasket so you should be fine.

 

[Vrabel]

if you need the big one for the W/P let me know. Dlr shipped me a bag of 6 at $30 a pop. Learned real quick to ask how it comes. also have some for rear cover and a few other misc ones.

 

[sweetdiesel]

Sadly every gasket i reuse leaks

I look at it this way....If the time it takes to replace the gasket is more than the cost of the gasket, I replace it.

 

[sweetdiesel]

Best thing i ever did was buy a metric o-ring kit it was around 60 bucks but has almost every o-ring you could need besides the big one on the water pump

I have enough o-rings to rebuild 8 more times

 

[Cougar281]

Best thing i ever did was buy a metric o-ring kit it was around 60 bucks but has almost every o-ring you could need besides the big one on the water pump

I have enough o-rings to rebuild 8 more times

I guess there's nothing special about them? I have a Harbor Freight near me and they have several different tyos of O-Ring kit (Viton, Nitrile). Is there a particular type I should get or stay away from?

 

[sweetdiesel]

Well the only orings that ive noticed that are different are the orange ones on the inj cups

the ones that came in my kit are thicker and work better imo.....Sorry dont know if they are nitrile or viton

 

[JoshH]

I would suggest you change the o-ring on the top of the coolant pipe that goes between the water pump and the thermostat housing/coolant crossover. I've had that thing leak on me twice.

 

[ripmf666]

If you need the injector copper washers and o rings for the injectore let me know I have 6 sets for the LB7 here and 2 sets for the LLY,LBZ,LMM here. Head gaskets the bolts if not going studs the orings on the rear adapter the 2 orange ones.As Josh said the cross over tube o ring upper and lower.

 

[sweetdiesel]

I would suggest you change the o-ring on the top of the coolant pipe that goes between the water pump and the thermostat housing/coolant crossover. I've had that thing leak on me twice.

that is actually where the thicker oring is nice it never leaks and after all the coolant issues ive removed install that oring 3-4 times now its a lil tougher to get in but never leaks....and you know the luck that i have

 

[TheBac]

I would suggest you change the o-ring on the top of the coolant pipe that goes between the water pump and the thermostat housing/coolant crossover. I've had that thing leak on me twice.

LB7 injector cup oring works nicely there.