I know this might not be a leak most encounter, but when I rebuilt my engine, I used a little RTV on the o ring for the cam plug in the back of the block, did good for 120K or so, then I added Lucas oil supplement, WOW at start up had near 100psi oil pressure, started leaking like a sieve, any way this time no RTV on O ring but I did use Permatex sleeve retainer # 64000/ and the Surface prep/activator # 24163. Hoping it will last me more than 16 mo's.

Typically o-rings you not suppose to use any sealant on any o-rings. Heck I pulled the adapter plate off of the 2006 and didn't even mess with it and bolted it back up. I pulled it to change the rear main seal. No leaks.

As moparman said above o-rings shouldn't need additional sealant.  You also need to be careful what you use to lubricate the o-ring during install.  Even Vaseline will ruin or breakdown some o-rings.  Depends what kind of service is in as to what should be used for lube.

 

I worked on many industrial compressors and depending on what type of service, if you used to wrong o-ring lube they would fail within hours, in some cases immediately. 

 

Sometimes the lubricant reacts to the oil or gas as well.

I always used regular motor oil on orings with no issues. As for Lucas idk... shouldn't need it unless engine is wore out that stuff is like glue. 

All true above. I normal use the same oil the system is running. Like A/C I've got a bit of PAG oil. Engine stuff I use engine oil. Pretty simple.

I rebuilt a 12 valve it had a swell plug back there that was supposed to seal up when hammered. I didn't  much care for it. 50 k mile later has some leakage from either the rear seal or cam plug.

17 hours ago, ddmk6 said:

As moparman said above o-rings shouldn't need additional sealant.  You also need to be careful what you use to lubricate the o-ring during install.  Even Vaseline will ruin or breakdown some o-rings.  Depends what kind of service is in as to what should be used for lube.

 

I worked on many industrial compressors and depending on what type of service, if you used to wrong o-ring lube they would fail within hours, in some cases immediately. 

 

Sometimes the lubricant reacts to the oil or gas as well.

 

17 hours ago, Dieselfuture said:

I always used regular motor oil on orings with no issues. As for Lucas idk... shouldn't need it unless engine is wore out that stuff is like glue. 

I didn't use anything this time, set it in the groove, used the above mentioned sleeve retainer/activator and used a big brass drift/BFH and smacked it a couple times. See how it does.

17 hours ago, Dieselfuture said:

I always used regular motor oil on orings with no issues. As for Lucas idk... shouldn't need it unless engine is wore out that stuff is like glue. 

Yea, I agree, I was sold on Lucas when my power steering pump was leaking a half Qt a day out the sector shaft seal while on the on the road in NH , stopped and bought a Qt of Lucas Steering stop leak, 3/4 through the Qt the leak stopped. But my engine only had 120K on it and they advertise it to help on startup, My bad. When I rebuilt engine the mains/rods were right on according to plastic gauge, this with the original crank w/853K, still standard Mains/Rods. Learned my lesson the hard way. Now on straight oil Rotella 15-40, only, Donaldson filters.

 

 

Edited May 29, 20213 yr by Blueox01

On 5/29/2021 at 2:02 AM, Blueox01 said:

On 5/28/2021 at 9:15 AM, Dieselfuture said:

 

Yea, I agree, I was sold on Lucas when my power steering pump was leaking a half Qt a day out the sector shaft seal while on the on the road in NH , stopped and bought a Qt of Lucas Steering stop leak, 3/4 through the Qt the leak stopped.

 

Be careful. If you use too much of that product it can and will blow the pump or the hoses. I've seen it done on a older Ford pickup and the thickness of the product can increase pressure sharply and blow things up. The owner of this truck just kept adding the product and eventually it blow the pressure hose in half.