help water hose exploded 1.9 dg on way to vanfest

[t25-bobbee]

rubber water hose exploded 1.9dg ,no over heating,no loss of power,passengers just heard pop then lots of smoke,hose from water pump top 1 split about 1 foot long , any idears why or was just old age.

[kevtherev]

I would change your expansion tank cap. (High pressure tank, The reserve behind the plate is the overflow for it.)

[ghost123uk]

I had this once and it turned out to be a blockage in the pipe that comes from the rear of the top of the nearside head. This pipe is "fat" at the cylinder head end, but goes thin to connect to the pipe that runs all around the top of the engine bay. The "T" piece where the rubber joins the metal pipe was blocked. This can cause water in the nearside head to boil and if the blue "dalek" cap cannot keep up, makes pipes burst !

After it happened to me, I went through all the narrow bore pipes (like the one that runs around the top of the engine bay, and the one at the top of the (plastic type) thermostat. Much crud was removed !!

I too fitted a new (genuine VW) pressure cap.

[t25-bobbee]

thanks for feed back,just ordered (genuine VW) pressure cap from brickworks. I'll clean all the pipes let you know how i get on cheers, still got to vanfest but in the car

[ghost123uk]

I got mine from Brickwerks too

Yep, blow down all those thin pipes to check they are clear.

Don't forget you will need to follow the fairly specific T25 bleeding procedure after filling up with your 50/50 water and G12 (or Comma equiv = cheaper) - Info on bleeding is in our wiki ^^^^ if needed.

I lost £20 worth of Comma G12 when my pipe burst

.

[toomanytoys]

I lost £20 worth of Comma G12 when my pipe burst

.

Hence why I would never use G12 unless the engine is "new"...

But.. the waterpump cannot generate enough pressure to bust a pipe in a blocked hose, that can only be done if the pressure cap is faulty or blocked with gunk.. or if a head seal has blown/head studs snapped, or little circulation causing the engine to get very hot boiling the coolant and pressurising the system..

[t25-bobbee]

Fitted new hose and new cap,bled system, took for run today running great no leaks,all fine , thanks for all your help cheers

[kevtherev]

It's nice when folks get a problem sorted... and this forum helps in some way.
thanks t25_bobbee, for letting us know.