Head to block breather

[steveww]

I am having great fun and games getting the head to block breather tube to seal, which is causing an annoying oil leak. Anyone have any suggestions on the process to get this to seal properly?

[types26/36]

If you are fitting it with the head still on, use a sealer (I use Red Hermitite) and once the tube is in place rotate it making sure the lips locate in the holes correctly. It is quite hard to rotate it but the sealer helps it to move, rotate it a full 360 degrees to make sure it is seated.

[nebogipfel]

I don't know if this is any help but the first one I fitted to my engine leaked. I replaced it with another new one and so far it has been fine.

It was fitted without any sealer and with the head on.

The only difference I noted between the two was that the second one was noticeably softer.


Everything else leaks but the breather tube is OK

[chicagojeff]

i have a related question...how do you know it's the breather tube? i ask, because i have an annoying leak from somewhere under the top of the head...the sign is a tiny puddle on top of the corner edge where the block and head meet (in the rear of the engine...).

It appears after running. thanks, and can that tube be sealed up in situ?

[types26/36]

leak from somewhere under the top of the head...the sign is a tiny puddle on top of the corner edge where the block and head meet (in the rear of the engine...).
It appears after running. thanks, and can that tube be sealed up in situ?

Jeff, there is a welsh plug (cor plug) or whatever you guys in the U.S. call it close to the tube in the head, could be that is leaking, could be your cam cover or D plugs are leaking and running down......could even be your fuel pump but you say it is higher then that......clean it off and try to find the leak may be with the help of a mirror.....
As for trying to seal the tube in situ......it just never worked for me and I would never feel right about having a big dollop of silicone seal slapped on the engine......but if you can live with it have a go
see this thread: http://www.lotuselan.net/forums/viewtop ... ght=#73076

[JJDraper]

If you have the head off, its worth checking that the hole in the head is machined to the correct size... Mine is not, in fact has never been machined and caused a big leak until I modified the rubber breather tube to fit. The diameter should be larger than the hole for the core plug next to it. Mine is smaller, but apparently (according to QED) there are a lot of poorly machined heads around - friday afternoon jobs!

Worth checking...

Jeremy

[steveww]

I recently had the head off to replace the head gasket (an other story)

I fitted the breather tube when I refitted the head, but it now leaks. I think I may have been too quick in firing her up and not left long enough for the silicon to go off. I have ordered a new breather tube (Sue Miller - thanks). When it arrives I will give it a fresh smear of silicon and try again. I will be doing this with the head in situ. I have done this before and it is not too difficult; I heat up the tube with a hair dryer first to make it a bit more flexible. If I can fix this leak the engine may finally be oil tight, though I am sure it will prove me wrong here

[bill308]

Oil tight? Are you not defeating thechassis, corrosion control system?

Bill

[65 Lotus]

Have replaced the head-to-block tube twice now (head off) with success.

Step one is to make sure the head gasket is cutout properly in that area to accept the tube. I know the Cometic gaskets (Dave Bean, et. al) sells have to be relieved quite a bit for them to clear. I used a Dremel with a sanding drum attachment.

Always clean thoroughly around the sealing areas of the pipe with a solvent (I like MEK) to remove either mold release agents or engine oils if it's a re-use situation. Clean the metal holes too of course.

I slathered both sealing areas on the pipe with Permatex UltraBlue and pushed it home into the block. Then installed the head while the wife looked underneath to make sure it went straight into the bore. Did not rotate or wipe off excess, just allowed to cure fully before any oil was added to the engine.

Has been leak free. I do get a bit of a leak at the breather pipe grommet however (have the type that vents to the atmosphere) but have been reluctant to put sealant on it since it will be a mess upon install.

Can see why you'd want to rotate if installing with head in situ. I guess my only thoughts are to make sure all oils are removed, and the head gasket doesn't interfere.

[poiuyt]

I had a similar leak and solved it as follows:

Clean the area with Gunk or Simple Green or other grease remover and allow to dry.

Buy a flexible palette knife from an art supply store (about 3/8 inch wide).

Put some grey RTP or similar oil resistant sealer on the knife and spread it at the top and bottom jounts liberally until all of the area between the tube and the head (or block at the bottom) is covered.

Wait AT LEAST 24 hours to cure.

Looks a bit sloppy but it works and you don't have to remove the tube. Besides, who looks under there anyway.

Steve Becker

[john.p.clegg]

Steve
Get yourself a sharp craft knife,be careful re fingers,and shape the top or the rubber into a funnel before fitting,stops the oil pooling on the head....

John

[steveww]

Steve
Get yourself a sharp craft knife,be careful re fingers,and shape the top or the rubber into a funnel before fitting,stops the oil pooling on the head....

John

Good idea, thanks