Ok so I have evo 5, evo 8 motor. It seems to explode water hoses. So far have exploded tps return line and driving home today blew 1 of turbo water lines. Going to put ralliart thermostat in but am at a bit of a loss now. Any advise may be useful. Newhead gasket and studs 1000km ago

 

Hate to say it but excess pressure in cooling system is most likely a failed head gasket. Regardless of when that last one was replaced. Could be a warped head. Was head inspected when head gasket was replaced?

How are the condition of the hoses? Were they do for replacement? An old or oil soaked hose can fail as well.

 

Im picking its hose condition. Head has been examined mant times and we went through all that stuff before gasket installation. Car ranbottom endbearing so was a rehone just to get ensure everything was sweet

 

You could hope and "pick" all you want but J_Striker is right. Excessive pressure in cooling system is most likely failing headgasket.

 

The strength of the spring in the radiator cap determines the pressure in the system. The only way for the pressure to get higher than that is if venting at the cap can't keep up. That would be an eruption that would at least fill the overflow jug.

So, try a new radiator cap. On the other hand, the service interval for replacing water hoses is 60K but most people run them until they blow.

 

Thank you for well informed answer. No pressure coming back to catch bottle. We have some bad angles that we are working on as the hoses have not been straight enough. Also areas where blow out occurs are in old hose clamp spots. We have been down the head gasket road and we know this is not the case. Thats why we put a new head gasket in to elliminate this possibility. It has a cosworth gasket and studs and was f@#cking expensive. both hoses blowen so far have showen signs of wear and we working around the engine bay replacing any old hoses with new/better strength ones

 

Im not trying to bury my head in the sand and say "no its not the head gasket". I am aware that this is how excessive pressure gets in the water system. This is something we have spend a lot of time and money going over to eliminate and its very frustrating. I do appreciate all opinions posted though

 

That's a good attitude to have!

 

Awesome advise m8. Got another cap coming as mine heavy duty hks so go bit softer and upgrading water pipes wen me new turbo goes on