Perrin/Mocal oil cooler - Torque spec for center bolt
 

Does anyone know the torque spec for the center bolt that runs through the middle and holds the Mocal sandwich plate and spacer together?

During my last oil change I must've inadvertently loosened the center bolt when I removed the oil filter. This caused a decent oil leak since there was a few mm play in the stack.

I took everything apart, cleaned it, and put it back together making sure to lube the double orings on the Perrin spacer as well as the flat Mocal gasket. I went hand tight/snug on the center bolt, but I checked it today and it's leaking again. I can slightly rotate the sandwich plate left and right so it seems like that center bolt loosened up again.

So yeah, anyone know the proper torque spec for this bolt?

25 ft-lbs

I wrote it on the underside of my hood with paint pen when I installed.

Thanks man. This is helpful for when I have to take it apart and clean it all up again on Friday when the engine is cold.

I also reached out to Perrin for the torque spec. Will post their reply here.

But how do you actually torque it? Have you found a socket that fits or did you shave one down? Asking because I'm looking for a solution as well.

I used a 27mm socket when I hand tightened mine, but it wasn't QUITE thin walled enough to fully sit flush around the bolt. Was still enough to grip it though.

I turned one down on the lathe to fit better. I have a few sockets like that now :bonk:

Too bad you aren't local. We could have an oil cooler bolt tightening party.

No homo.

LOL

Honestly you could probably get away with taking a grinder to a cheap socket. You really only need to add a bit of bevel to the bottom to get it to seat well. Even if you go through it or it gets thin, it is not that big of a deal. The torque spec is pretty low for a fastener of that size.

Perrin got back to me and also confirmed 25lbs. I guess I missed it when I checked the PDF of the installation instructions: "Fully tighten thermostat housing adapter. Using a 27mm socket, tighten to roughly 25ft lbs"

So it was there all along. Der duh der. Sorry for making a pointless thread.

Anyway, it would be nice if someone (Mocal?) made a special socket specifically designed to tighten these center bolts.

Could you not use a crows foot? Seems like that would be easier.

I reached out to Mocal to see if they have a recommendation for a socket that will work.

Here is their reply:


"Hello,

Finding a suitable thin wall socket might not be the easiest thing. Generally use a open end wrench works fine. Tight is similar to a filter: snug and 3/4 turn.

Regards,


Eric Weller
BAT Inc. / MOCAL USA"


What's interesting is that he doesn't confirm the 25lb torque spec that I mentioned in my email to him, he just refers to tight as being snug and then 3/4 of a turn. Hm.

I'll chime in with a couple issues I've noted with the Mocal adapter.

• I also converted a socket to fit between the tube and that bulge in the casting. International standards for tool clearances have been in place for damn near a century. I get miffed when I come across such design choices.
• On mine, the shoulder on the spacer was too tall. The spacer and adapter came into contact before the gasket sealed tightly enough. I ended up cutting off about three quarter of a millimeter before it all cinched up nicely.