Cylinder Head Breather pipe replacement / upgrade

[Peter +2]

I have finally traced an oil leak to the Cylinder Head to Block breather pipe. The pipe is so loose that I can easily rotate it. I have no wish to remove the Head but understand that the pipe cannot be replaced unless I do.

Options I see are:

1) to try and replace in situ - (not possible?)
2) to clean and silicon seal in situ.

or I am sure I have seen a removable breather pipe made, I thought it was made by Elantrixbits in Australia but I can?t see it on their newish website.

All suggestions / advice welcome.

Cheers

Peter

[john.p.clegg]

Peter
It's not mega difficult to replace in-situ if you warm it up before replacing,and a smear of silicone sealant , on both surfaces , not only helps as a lubricant but also sealant.

John

[richardcox_lotus]

The one I saw on here many years ago was a machined sleeved arrangement.

Like you, I can't remember who posted it ! Typical.

How much oil are you using ? I too have a leak which gives all indications that it's from the fuel pump seal, but I suspect it's from just above.

Regards,
Richard

[john.p.clegg]

lotus-parts-f33/custom-made-stainless-steel-head-block-drain-hose-t38504.html?hilit=oil%20drain

John

[Peter +2]

John,

That must be what I was thinking of but since the original can be replaced in situ, albeit with the usual Lotus ease (hassle), I will give that a go.

Richard

Mine is quite a leak, enough to leave a noticeable puddle, but interestingly you would not necessarily think the breather was the cause, that is, until I fiddled with it and found it to be quite loose.

Fingers crossed it is the sole cause.

Thanks

Peter

[nmauduit]

John,

That must be what I was thinking of but since the original can be replaced in situ, albeit with the usual Lotus ease (hassle), I will give that a go.

Richard

Mine is quite a leak, enough to leave a noticeable puddle, but interestingly you would not necessarily think the breather was the cause, that is, until I fiddled with it and found it to be quite loose.

Fingers crossed it is the sole cause.

Thanks

Peter

Same happened to me a couple months ago, I think the rubber shrinks and at some point just does not seal and suddenly let the oil leak around it... The new one I had laying around was actually 5mm longer and several mm larger in diameter. It was surprisingly easy to replace, what took most time was to remove the rear carb and refit it afterward (LHD car).

[john.p.clegg]

Peter
What I did , as well as the silicone , was to get a scalpel and trim the upper inside portion to form a funnel shape to help the oil drain rather than pool.....don.'t blame me if you end up with 4 fingers...

John

[Esprit2]

I've installed a couple of the rubber drain tubes in situ. It does help to heat the rubber first, but a dry heat is better then boiling it in water. Well, it was for me, since I also coated the top and bottom spigots with silicone sealant to supplement the seal, and I didn't want the part to cool while I messed around getting the ends really dry. Use an oven set to low heat, or lay it out in the summer sun on black asphalt.

Start the top spigot up into the head first, and apply some upward force to keep it in place while seating the bottom spigot into the block.

Using an adjustable Channellock pliers, grasp the rubber tube in the middle, pinch the sides together into more of a line than a tube. Then, using the pliers as a lever, and maintaining some upward pressure on the upper spigot/ head, bend the tube into an 'L' shape. You don't need to go to a full 90 degrees, just enough to get the bottom spigot to clear the boss on the head, and engage the hole, Then un-bend the tube, guiding it into the hole as it straightens out.

With silicone sealant on both ends, I've generally managed to make a mess out of it; but it cleans up easily with a rag and some aerosol brake or carb cleaner.

Allow the silicone sealant 24 hours to cure before starting the engine.

A NOS rubber tube that's 40+ years old will probably crack if you bend it; but then, did you really trust that old dried out rubber bit in your engine any way? Get a proper new part, one with a little life left in it, and bending it's not a problem.

Regards,
Tim Engel

[Peter +2]

Tim, John et al

Thank you all for the detailed helpful advice. It makes a job a lot easier knowning it can be done even if with a little force. I left the pipe in the boiler cupboard for a few days so very flexible and dry. With the carbs off and no fuel pump in the way it all went well.

I used silicon to seal, and currently all is leak free, so fingers crossed.

Cheers

Peter

[john.p.clegg]

" Leak free " ?

...are you sure you've got a Lotus ?

John

[ceejay]

Peter...I'm chiming in a bit late on this one, yes we did design and fabricate an adjustable oil pipe,
you can read about it at the link below... it does work.. but the problem is the bottom of the tube requires a flat surface on the block to be ground or milled for the bottom O ring to seat against... any way you should understand once you read through... Sorry, but we don't produce these for resale.... Far to busy with CVDS and gating and baffling of sumps.
http://elantrikbits.com/lotus-elan-blog/?s=oil+drainer
Ceejay

[rgh0]

If you make a rigid but adjustable length tube you need to seal it on the inside of the bore of the hole in the block. I think there are actually two diameter of this bore incidentally depending on the block age. The seal to the head can be done with a flat flange and o ring or suitable gasket forming sealant

The Elan factory made a solid alloy tube that was required to be a press fit into the block bore until its top surface aligned with the block top. Good and long lasting and I used a few over the years when they choose to take my money but it could not be changed with the head fitted. Since I moved to McCoy conversion racing heads I don't use the drain tube often as they do away with it totally .

To make a well designed tube that seals at the bottom you need an angle washer to suit the sloping block face brazed to the tube to locate it in the vertical position and an O ring on the tube in groove to seal with the block bore.

cheers
Rohan

[RichC]

I must confess this posting has surprised me...
the reason is that my breather pipe metal end is a push fit and i can easily remove the metal with the rubber hose attached with everything in situ.... and I don't have a leak here. no silicone sealant ... it just sits there behind inlet to cylinder 4
even when belting the car round the castle combe track at over 100mph .
there is crankcase pressure ( as i had a small leak off the filler cap when the rubber seal was dislodged). So i wonder why the difference in experience ?

[richardcox_lotus]

Rich it's not the breather pipe we are discussing, it's the head to block vertical drain pipe.

Regards
Richard

[RichC]

ah, so.. that explains it ! drain pipe not breather pipe