Bleeding the Cooling System

[handi_andi]

Hiya
I know that bleeding on the cooling system on a lotus elan plus 2 130 is a pain in the rear end from what I have seen of the instructions, althoguh I am goign to have to do it when I back flush the system to try and get the heater to work. I am also in the process of looking into Solar Heating at the moment and they always incorporate autmatic air vents into the system to assist with bleeding. It therefore occured to me whether it would be possible to fit one fo these just by the exit fo the heater matrix to assist in bleeding the cooling system on the elan? Anyone got any thoughts?
Andy

[ppnelan]

On a standard twincam, I think there is always air in the top of the cooling system as the radiator cap is lower that the top hose. I just fill it up and run it... Not had any problems. Perhaps it depends how low the radiator is ? In my limited experience, heater problems on a +2 are usually caused by the flaps (& seals) that divert the air in the heater itself, assuming the matrix passes water (?!) OK and is not too clogged for air to pass between the fins.

Matthew

[ppnelan]

By the way, if you really want to completely fill the cooling system I believe there's a special thermostat housing available with a filler cap, i.e. at the very top of the system.

P.S. 'Slightly off-topic', but.... My solar heating installation has only a manual radiator valve air vent - once you've got rid of all the air, there won't be any more unless there's a leak somewhere! Probably less true in the twin cam...
[Don't buy anything solar without looking at www.navitron.co.uk - I bought my components elsewhere, but the help available on the forum is invaluable... ]

Matthew

[Robbie693]

Never really had any problems bleeding the rad.

Park the car on a slope if possible, front end highest. Fill the system, run the engine. As it comes up to temp and the thermostat opens, squeeze the top hose a few times and watch as the bubbles rise to the top of the filler neck. By the time the fan cuts in all the air should be eradicated.

You may find the coolant level in the expansion bottle drops over the next few days of use, keep an eye on it and top up as required.

[john.p.clegg]

Andy
You.ve just helped me "click",if you need to bleed your cooling system it will have to be at the highest point,which is the top hose or thermostat housing,"cliveboy" does an altered thermostat housing incorporating radiator cap but if you're daring what is the matter with an innertube valve fitted in the top hose?

John

P.S. is it really that easy or am I missing something?

[handi_andi]

John
I get your point but how would you propose fitting said valve? Have ordered an automatic valve off ebay anyway just to see if it will work, only a fiver so not too bad given the amount I spent today on fuel sender unit and new master cylinder LOl
Andy

[elansprint71]

The heater is the highest point in the cooling system. The only way to really get all the air out is to fit a bleed valve in the end of a piece of hose tee'd off the heater hose at the high point and let the gas out when the system is hot.
Most modern cars have a bleed valve fitted at the high point, although it's not always obvious where that is (just like on the Elan).

Cheers,

Pete.

[hatman]

Some of these technical solutions are quite ingenious but as I'm just a simple soul I replace the coolant with the front wheels on car ramps, thereby ensuring that the radiator top is the highest part of the system.

[handi_andi]

Well the bleed valve arrive today, so just need to sort out a way of teeing it into the cooling system somewhere around the heater and then mounting it so it is the highest point in the system. The one I have got has a 15mm compression fitting on the bottom of it so some domestic plumbing bits n pieces from the box in the loft and some rubber pipe bits the local motor factors will hopefully allow me to fit it into system. Anyone got any bright ideas for where would be a suitable place to mount it, given that the drivers side is quite congested with the heater conenctions, pedal box, manifold etc?
Thanks
Andy