Thermostat O-rings
 

Well, if ever this weather lets up, I'm going to have to change the O-rings as I have coolant in the "V". Although I fitted a new thermostat a couple of years ago, I can't remember whether I can change the O-rings without removing the thermostat, as I do remember it was a tricky job!
Can anyone advise me please?


Thanks,
Malc

Hi Malc,

Yes, you'll need to remove the thermostat, straight and curved plastic pipes to replace the four o-rings (CDU3858).

Whilst it's a bit more work, I'd recommend removing the plastic intake and front (left) inlet manifold. With them removed you have much better access to clean the mating faces in the engine block (with some Scotchbrite or similar) that the o-rings sit in and you can be confident that it's all properly seated. You will need a new manifold gasket (LKJ100992) though.

https://www.the75andztclub.co.uk/for...7ae22da1aa.jpg

Hope this helps.

Thanks very much Matt. I can see from your excellent photograph that the access is vastly improved! Thanks for the part No. refs as well.
Malc

And Malcolm, after reassembly make sure that you push the serrated clips on the straight pipe fully outwards to be in close contact with the water pump boss and thermostat housing, then squeeze them tight.

I'd recommend ordering two new clips (along with the O rings) to make the job easier. The part no. is PYC 101320.

Simon

And, if you have one or both parts of the intake manifold off don't forget to order new manifold gaskets. :}

Cooant in the " V "
 

Hi Malc,
Interested in how the job panned out regards replacing the "O" rings on the straight pipe and fitting the serrated clips flush up to the water pump at the one end and the thermostat housing at the other end thinking that surely would eliminate any seepage of coolant into the V.
Very interested to know how it all went and that you cured the problem.
Cheers
Rick'

Thanks everyone for your help and advice. I'll be sure to let you know how I get on as soon as we have a couple of dry days - when ever that might be!


Cheers,
Malc

Well finally got the job done, although in the end I decided to go the "keyhole" method. Its a difficult job no matter which way you do it because there are so many components to remove to allow access to the hose clips.
When I finally got all the components out, it was apparent that most if not all of the O-rings had flattened.

https://www.the75andztclub.co.uk/for...7e47fdefeb.jpg




Last time I did this job(only three years ago!), Iused an extended 1/4 inch square drive socket and universal joint.
This time, I found an easier way - using an extending flexible screwdriver to remove the thermostat fixing bolt.


https://www.the75andztclub.co.uk/for...7e4807ae3e.jpg

The tricky bit is you need a hex to 1/4 square transformation piece to allow the use of a 10mm socket.


https://www.the75andztclub.co.uk/for...7e4810d24d.jpg




Also, I found a miniature inspection light to be very useful so you can see what you're doing!


http://img]https://www.the75andztclu...93216a5a3f.jpg
https://www.the75andztclub.co.uk/for...93216a5a3f.jpg


In case you're interested, this small 12v bulb came from the end of an indicator stalk from an Austin 1100, which I just happened to have lying around!
Other must-have tools included a pair of self locking snipe-nosed pliers and a long reach flexible grabber(to insert and remove the bolt)



Anyway, the remaining orange waters in the Vee are now receding and I'm just keeping an eye on the coolant level in the expansion tank


Malc

Yes ,i have got one of these,but with an handle for a socket one end. Got me out of a fix on bad access bolts a few times. Tough as hell and bends around corners. Got mine at a car boot , and was worth more than the £1.00 i paid. :D

Are the 'O' rings available separately...I've done the same job myself some 8-10 years back, everything new and OEM, and it's still all good (....now I've done it saying that) but it's worth keeping spare 'O' rings in stock.