I've been using Hylomar form decades. Back in the '70's when I was riding leaky British bikes, there was no silicone sealer...or Hylomar for those who didn't know where to get it. Made for Rolls Royce, we used to get it from the Foden dealer, because they used RR engines. Silicone sealers came to save the day, but I always have Hylomar on hand...still a tube in the shed.
Great stuff in the right applications, especially good at stopping seeping on traditional cork gaskets. I also like it on threaded fittings that I have to occasionally dissemble. Make sure you get the original, someone had a license to make it here at one point. One warning; use sparingly. Unlike RTV, it doesn't harden so any significant squeeze out will detach and can block, say, a carb flange vacuum port.... Guess how I know that?
'05 Lotus Elise S/C '85 Land Rover 90 diesel '74 Triumph TR6 '74 BMW 2002 '72 Land Rover Series III 88" '99 Porsche 996 (Wife's) '01 Porsche Boxster S (mostly Wife's...) Piper Pa28-236
Permatex makes Aviation Forma- Gasket and I've been using it for ages. If the edges were smooth and the torqued applied right it works great. I used it gluing case halves together when rebuilding bug engine. They make a thinner version that is brushed on and used as gasket glue. It is used for the same uses as Hylomar. Permatex is widely available
'16 Camry LE STP synth 0w20 and STP filter. the Fridge
1994 Ranger ,the Rat, 5w30 dino, STP filter
'16 Camry SE, Valvoline HM 0w20 and OEM filter Thick oil is better
Man, I could have used that when I resealed a Subaru oil pump during a timing belt change - while it calls for RTV, extreme caution needs to be exercised to avoid squeeze-out that can break free, plug an oil gallery or passage and ruin the motor. I used Loctite 518 instead.
I think the OEMs back then didn't want to test the FIPG waters out and Hylomar was probably too expensive for OEM production line usage.
You did right with the loctite, an anaerobic like 51813 is much preferred over RTV in that particular application. Hylomar could also be used with no problems if there are any gouges in the aluminum parts as it unlike an anaerobic with very limited gap filling ability is good at filling gaps.
The downside is cost, its not cheap but unlike RTV where most of the tube goes in the bin after one use the Hylomar stays usable. One of my favorite uses for it is on hose nipples, just a thin coat will seal the hose regardless if its air, coolant, oils, gasoline or diesel without hindering future removal, you still have to use the clamp though.
For coolant leaks on plastic coolant nipples when the temps drop to zero or below and you keep tightening the clamps to stop it Hylomar is the permanent fix. Spread a thin film on the plastic part, put the hose and clamp on then tighten firmly but not over tight and forget it.
RTV is useful for steel covers but where aluminum flanges and covers are used Hylomar is superior. Now I only buy the samllest tube of RTV and open it when I need it then toss it and get another. The rest of the time I use Hylomar.
Anaerobic has its place on assembly lines where something has to cure in 15 minutes or less. It sticks well enough, too, but in the service world RTV is suitable if not excellent for those with more patience.
Not true in every case especially the Subaru oil pump or heads that have a separate cam holder where additional thickness may be an issue. In that particular application an anaerobic is sometimes mandatory.