Sigma owners - Check your plastic tee piece

[Jonathan Kay]

Well done

Jonathan

PS: Tees?

[BigCol]

As my 140 SuperSport is three years old, I reckon it's wise for me to make this mod.  

However, I can only see one T in my pipework - a large diameter one in the pipe from the rear of the engine (well, the heater in my case) to the expansion tank as per the mid-green pipe in this diagram:

http://i1366.photobucket.com/albums/r765/BigCol911/cooling%20system_zpsks9mn4rb.jpg

Have I missed something?  

Also is that a 16mm (ie 5/8") or a 19mm (3/4") does anyone know?  Reading above, martyn / RedCat7 mention both sizes.  What ages are your cars?

(I would acknowledge the author of the diagram above but I am afraid I have forgotten his name - but he posted details of his build on facebook in 2013 just ahead of me building my car.)

 

[martyn]

In my case, there is a small tee in the yellow hose soon after exiting the upper expansion tank, connecting to the top of the radiator.  I guess you don't have this otherwise you would have easily noticed it.

You probably need a 16mm one.  That is what everyone else has used and it is 5/8" hose after all.  My car is a sigma 150 and has the modine oil-water heat exchanger connected after the tee.  That possibly explains why mine is different.  Easiest way to check it to measure the diameter of the visible part of the tee piece.

[alcal]

I have the same arrangement as BigCol. Having just measured the OD of the Tee piece ( tricky when in-situ ) I'd say it's 19mm.

[BigCol]

It is 19mm alcal...  well, to be pedantic, the plastic t-piece removed was marked 3/4"  

[diggerman]

 

I started this subject on the 15th May 2015 having just dumped all my coolant on the car deck of the Britanny Ferry to Bilbao. As reported at the time, I replaced the original Caterham plastic tee with a locally bought Husqvarna plastic irrigation tee.

i finally got round to replacing the Husqvarna part this morning. (must admit, not a very quick reaction to my own warning!) Glad I did as it was also on the point of failure. Clearly plastic items can not cope with the temperatures involved in cooling systems.

Todays solution was to use a standard brass plumbing tee, the type with compression fittings. In to each outlet I have fitted an 1 1/4 inch long piece of 15mm copper pipe. Each pipe has an olive soldered on the end, this being a tight push fit in to the hoses that run from heater, oil filter nacel and header tank. The jubilee clip fits over the hose between the tee and the olive making a very neat and secure solution.

Quite pleased with myself really .......

PS Car is a Sigma150SV

 

[Dorset7]

 

[Sean2015]

 

Having recently suffered a similar failure I would like to reiterate the previous findings and advice from Diggerman and others......

The plastic tee pieces fitted to the water cooling systems on the Sigma engines are prone to distortion and then fracturing. I have replaced my larger (failed) tee with another plastic item until the brass replacements arrive (hopefully tomorrow).

Like myself, newer (and some existing) owners may not be aware of this issue. Not sure how long the tee pieces take to deteriorate, my car is 6 years old. So far, the re-filling of the system with water has been straight forward with no complications.

2010 Roadsport 125