Coolant hose split- an autopsy and SHOCK DISCOVERY

My pipe blew in the exact same spot on the way home from picking up my F, so I thought I would cut it up after reading this to see if mine was the same. Here are my findings...

My hose blew out in the exact same spot as David's... Same symptoms.. Steam etc. (unsurprisingly!)


Pipe was almost completely blocked.


Closer view from different angles



To me, it looks like it should sit like this in the pipe

Looking at the piece that came out, it looks like it has been glued in place originally but over time with the heat and pressure it must weaken the glue and let the piece move out of it's place.

My piece moved up as far as it could and had rotated 90 degrees to almost block the pipe completely


Here is the offending article.


Looks like it may be worth MGF owners giving this pipe a squeeze to make sure this piece of plastic has come unstuck from where it is supposed to be and blocks the water flow.

So not a one off, then! It seems to be part of the jiggle valve as the rest is composed of the same material. Also the ball bearing fits neatly into that hole in it.

I will investigate the new jiggle valve when it arrives as part of my new hose. :pop:

And I agree it would be well worth while having a quick look to see if this is happening in your cooling system.

Interesting revelation.

maybe worth using a jubilee clip underneath that area to prevent in from slipping and dropping down which might prevent it from being able to turn and block the pipe.

Personally, I don't think that it is part of the jiggle valve as it has just moved too far. I think it is just a restricter in the pipe with the ball from the jiggle valve fitting just being coincidence. However, I may be wrong. When you get your new pipe you will have to give it a squeeze and find out.

David I don't suppose you will be cutting the new pipe open to check will you ?

my pipe split in the same place last october i bought a t piece and a 22mm to 18 silicone hose and buypassed the valve .i did wonder what it was for every think seems to be running fine

Tibs wrote: David I don't suppose you will be cutting the new pipe open to check will you ?

No, but I will pop the top off the valve to have a look. (Like I said -Nosy git)

I would imagine its to restrict water passage around either the head to allow faster warm up if you have PRT stat

Or to allow faster heater warm up if you have PRT stat.

Ok, Thanks to me old mate Russell, i know know that this part should be positioned so:-

so is this jiggle valve required ? if it risks over heating/hgf maybe its best binned or as said earlier secured with a jubilee clip to stop it moving

The wandering part is actually a reinforcement/restrictor and not related to the jiggle valve.

Should be like this Jiggle valve *(ball bearing in a plastic cage)
Two reinforcing tubes, one with a flow restrictor.