I’ve had the same issues so I’ve gone back to the ally bolt on ones I used to use on previous motors . Maybe it’s just the easier to fit thing but. O issues with mine but non stop, leaks or dribbles on the steel stock ones with bails. I glue the gaskets in with blue hylomar then just wipe some oil or grease or whatever might be handy over the other gasket face then just take a bit of care getting it on flat then pop the nuts on. Just finger tight with a socket on the nut then a quarter turn with a spanner. Ozziedog,,,,,,, sorry to all them stockists here.
Use stock covers or the Bugpak ones. Use new bail springs. Use standard cork gaskets. I find that if you trim them down slightly with scissors about 1 to 2 mm at either end on the "vertical" sections, then the gaskets will lay flat without sealant. No leaks. If mine leak around the covers it's actually the pushrod seals leaking, because the tubes are not stretched back to the length given in the Bentley manuals.
Thanks. I loosened the bottom cooling plates to look for pushrod seal leaks. They are fine, as I gave them a real light touch of permatex aviation sealer, too, when I rebuilt it all. It’s deffo the covers. Maybe the gaskets are too thin, or the springs to weak. I did bend them in a bit, and it was an effort to get them on…
Old rusted bail springs were a major cause of mine leaking in the past. The new springs make it really hard work to unclip the covers. Normally I smear the pushrod tube seals with a little oil after stretching the tubes back to the correct length, clean no sealant as you have to get all the sealant off properly next time if you start crudding up sealing faces with sticky lumpy stuff. I didnt do it properly as I couldnt stretch the stainless steel tubes by hand .. so some of them are too short, and two drip very slowly .. The other reason they can leak is if your breather isn't right or you have let the gaskets ride up as you put the covers on ( trim down or use that sticky crud.. )
The breather next to the oil filler into the air filter, you mean? Yes. Regarding the gaskets, I just used that Permatex aviation stuff, gasket to cover side, but I let it dry, or as dry as it gets, then carefully placed it onto the head being careful not to slide it around, then levered the clip back up. I let it sit for a while, then just went out for a 15 or so mile drive. Came back to it leaking again. On the plus side, the engine is preforming well, done about 240 miles now, since the re-re-build. Sound good, too.
Yes with the breather- if it is narrower than the 20mm inside diameter hose on a stock breather it could be adding pressure to the crank case. But if you can get the bail springs off by hand without it being a real fight (and even with a screwdriver it should need a fair effort) , you probably need to bend the springs or replace them to properly crush the gaskets onto the head. And check the rocker covers arent just fouling on the head casting so they will never seal until you trim down the edge of the cover where its touching. When my gaskets come out they are noticeably flattened where they contact the head.
It depends , the later 20mm breather is the same as the Golf.. the main thing is that the breather is not the prettier EMPI aluminium oil filler neck one with the 5mm diameter hole in the spigot that feeds a 13mm hose. Just the cyclic pressure variations in an engine case with good piston rings is enough to start pushing oil spray back around the pulley using the EMPI breather, and if the piston rings are a bit gone then there will definitely be an oily mist with that EMPI breather.
Everything is standard. I would say it’s even the original right sized pipe with no splits. Still squeezing up ok with the pipe clips. I use a rag and a ‘good tug’, to get them off.
[l Ok. These came today, so I put the gaskets in with a tiny amount of sealant on the cover side, and a little grease on the head side. Havnt ran it yet, so not sure if the leaks are cured. I did put both the old covers onto a large piece of glass to see if they rocked. Both did, so I’m guessing they were warped due to heat. The new ones laid perfectly flat. So I’m hoping all will be well now. Time will tell.
If they were warped, look at the warp and compare it with the cylinder head castings.. look for witness marks where maybe the covers rubbed.. Unlikely for mild steel to soften before the aluminium heads have cracked up and warped.. Or try to put the new covers on by hand and see if they rock on something before doing them up..
There are no marks on the cylinder head. I know the bit you mean, by the pic on here somewhere. The covers, if you imagine them on a bit of glass the right way, sort of rock diagonally, so top right corner and bottom left corners are the low parts. Sort of thing. The new ones have no rock. On or off the heads.
After failing to stem a rocker cover leak, a mate with a T25 wasserboxer opted for the silicone rocker cover gaskets from custom and commerical - problem solved.
Yet when I got some they leaked really badly and whatever I did I could not get them to seal. When the engine got hot they would change shape so they got chucked over the fence and replaced with the cork ones from GSF has be fine since.
