Gasping for a new gasket

So I’ve been walking to my new work the last couple of weeks since moving interstate which means the Stagea has been getting a well earned break. Unfortunately by not going anywhere, it’s collecting cobwebs and tree sap at an alarming rate so when it finally gets back to operational condition (when I finally get round to working out what’s going on with the turbo) a big clean is on the list. Today though our task it to sort out a pretty obvious oil leak as the infamous rocker cover leak rears its ugly oily head once again.

It’s been leaking for a bit and since it’s been so minor, I haven’t worried about it for a while. But now that I have some time and spare coin for parts, today it’s time to get this sealed up once and for all. The good news is, unlike the first time I changed one of these gaskets on the WRX back in the day, this one is top mounted. So no acrobatics in a very confined spaces to very slowly get long bolts out with a ratcheting 10mm.

The bad news? It’s still under a bit of stuff so these have to be removed first before the cover comes off.

The green shows roughly where the rocker cover on the exhaust side lies.

First things first though, we’re going to need some bits and pieces

Since we’re working with the Neo version of the RB25, we’re going to need the Neo specific gasket. For the exhaust side, it’s this one: 13270-5L301

Rb25 Neo rocker cover gasket

I read someone suggesting I’d need a new half moon gasket too (might as well replace it while the covers off) so I grabbed one too.

half moon gasket

Both of these are available through Just-Jap here in Australia. Huge shout to the the business too, I ordered these one day and the very next day I got a call from the delivery bloke at my door wondering where to leave my parts. That’s very speedy service!

I usually use Permatex Black (which was handy for both the WRX job and creating a gasket for the Stag IACV) but since the local Repco didn’t stock it, it’s time to try this instead: JB Weld Ultimate Black. It’s a maker and sealant so should more than do the trick in keeping our new gasket there and leak free.

Jb weld ultimate black

The process

It’s pretty obvious what you have to move to completely clear the rocket cover for removal and it’s a pretty easy process (just make sure you keep the bolts and removed bits in orderly piles to get them back in later). Some of the bolts on the cover were verging on loose, others required a bit of force. However there was one thing that gave me pause for thought:

rb25 neo

This black bracket is a support for your J-Pipe and the top plastic cover and is in the way of one of the bolts on the rocker cover you’ll need to remove. While the long bolt up front is easy to get to, the one closer to the firewall certainly isn’t and I didn’t have a tool that could easily reach around to undo things unless I was willing to take off the exhaust manifold to get to it. So first I tried wedging something in to give me enough access to the 10mm socket..

However even bending the bracket slightly did not give me enough room to get the socket in and at the right angle. Thankfully someone on Facebook pointed out that I could still get a long screwdriver in there and in combination with a magnet stick so I didn’t drop the freed bolt, out it came.

Once they were out the cover came away easily and I got to see how well the old gasket was doing….and yeah, it’d had a hard life (possibly twenty plus years if it hadn’t been changed before I got it). It was stiff as a board and fell to pieces once I stripped it away. Given the condition I’m sure I’ll have to do the other side soon enough (no leaks there at the moment through!)
rocker cover rb25 neo
























Once it’s out, everything gets a good clean and scrub with degreaser, especially the channels the new gasket is going to go into and the mating surface on the rest of the engine. It’s a good opportunity to get rid of a tonne of grime and shit that’s been there for a very long time as well as any old sealant from last time (mine didn’t have any apart from on the half moon at the back)..

Also don’t forget to throw out the old half moon and clean that opening too.


A line of sealant goes in – don’t stress if it’s uneven, the gasket going in will push it around into place anyway.

In goes the gasket (make sure it’s sits in nicely and isn’t bulging anywhere)

Now this might be overkill but I also like to apply a thin later of gasket sealant on the flat side too. Call it extra insurance etc but it’s a job I really don’t want to have to do again in a hurry. Once it’s in, do the same for the half moon (line of sealant in the opening and then line it up) and now things can go back in place, looking so much cleaner now too!

Don’t forget to give your bolts a bit of a scrub too. Chances are they’re just as filthy as the cover was before the degreaser came out.

Now there is a tightening order putting the bolts back in but the problem is, I don’t have a torque wrench yet and because of that black bracket earlier, I couldn’t get a socket in anyway to get it to the correct settings. If you do have the wrench and proper access then the settings are:

rocker cover torque settings rbb25

If you don’t (like me) then ‘a half turn before finger tight’ was something that came up on the SAU forums and that worked just fine for me. You want the cover back on, not to crush the gasket beyond all usefulness.

From there just reinstall everything you took out and like me you’ll probably find it’s a lot quicker process putting them back than undoing things.

The sealant needs an hour to dry but if you can let it sit overnight, even better. Give the wagon a drive, come back and check for leaks. Hopefully your block is still clean and stray oil free!

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