Burst coolant hose

[Volvogreen]

Burst coolant hose, first day of our sailing Holliday. It’s the water heater coolant circuit. Engine is a Volvo penta D2-75f 2019. Pipe seem to have ballooned and burst just at the hose clamp fitting behind the fuel filter. Beyond changing the hose, what could be the cause of this?

 

[Tranona]

Looks like the hose has delaminated. Unusual ass that type of hose is usually robust. Not really anything to do with the engine as the plumbing for the calorifier is fitted by the builder.

 

[Volvogreen]

Thanks. I dont know whether the delamination was caused by the process that resulted in this, or if it was previously delaminated. Hose is rated for 7bar and 170 degree Celsius. I also suspect air in the calorifier as those hoses were disconnected during cooling water change. Some work was done to clear air after changing cooling water, but maybe not enough. Engine was also test run for an hour at high temp a few days before this so quite odd it didn’t burst then if this was the issue. Pictures here from water heater side.

 

[pete]

As a precaution I would change or test the pressure cap on the cooling system.

 

[Volvogreen]

As it turns out, this was Indeed a bad hose problem. The original high tech hose started to break down. Now changed to a more traditional rubber coolant hose. Run 150 miles with the new hoses thus far and all seems ok.

 

[mrangry]

I have just replaced these hoses on a boat and used 16mm silicone hoses on ebay

 

[thinwater]

That is an EPDM hose. While very good for hot water and steam, they are notoriously, famously vulnerable to oil (Google it). If oil spilled on the outside, or if there was any oil in the block left over from manufacture, failure is not unlikely.

Silicone is fine, but it is more permeable to coolant (the level may creep down) and they can be challenging to keep from leaking at the fittings. Some people love them, some people hate them. A good fit and good clamps are vital.

(Based on lots of industrial experience. I recall a major bus line that had to recall all of their buses because an EPDM coolant hose ran under the oil dip stick. A few drips ever few days ruined them all. I was the one that pointed out the routing error.)

 

[RivalRedwing]

so, if I read the sitaution correctly, it is something the original installers should have been aware of given the location of the pipes?

 

[ChromeDome]

The specification for the pictured hose states

• Suitable for demineralized water, cleaning fluids and chemicals

Wonder if all coolants fall into that category?

During 56 years of boating I've used the same hoses at specified for cars when needed, so far without any issues.

 

[38mess]

My Perkins M30 same engine as Volvo 2030 burst a coolant hose at sea with passengers on, it was the big hose coming down from the HE to the water pump. Over the years it looked like it was rubbing against the upper sump bolts and finally gave up. I now have a wooden batten over the bolt heads.. it's a very tight fit.