Pipe is cracked behind the water pump at weld rubber hose on either end need to know how to repair or replace that pipe

water pipes burst from 2 reasons
one is that they are too old and have cracked the binding inside the rubber
two is excessive pressure from a head gasket/cracked head problem
if the hoses are larger than the clamp, they will burst
if they have been removed incorrectly the fabric in the rubber gets torn and they will burst
if the pump was fitted incorrectly , then high pressure from overheating will make them burst

just replace the rubber hose with one that is rated for gasoline and ethonal

You have a cracked block

Why would you do anything but replace it
or possibly weld it,once out & all apart & cleaned

its not normal. the water pump will leak in front, not back. There is a pipe and hose down in the VEE that can leak. If the pipe is bad, you will need to remove the pump to replace it. The intake manifold will need to come off, to replace the pipe/ hose. the hose connects a pipe behind the water pump to a pipe at the rear of the block to a heater hose.

It sounds like the outlet pipe from rear of water pump,which takes the hose from the rear plastic pipe, which is very common problem in Daewoo Leganza/Nubira/Lanos Australian 2.0/2.2 DOHC engines.Either the hose itself, the plastic pipe, or the alloy outlet for the hose on rear of water pump, which is subject to corrosion.You will have to confirm where leak is from, if it is from hose to rear of water pump, you can try re-clamping hose or replacing hose, if it is corrosion of that outlet,the part is available @$40-60 new, but it is a fairly major job because timing cover timing belt and then water pump must be removed...it is a difficult workspace in front of and behind that engine,the manifold and alternator are both in the way , it may be possible to do it in car but you may even be better off removing engine to work on.Good news is that this is a great opportunity to replace T-belt and water pump and pulleys at the same time..Sorry its not that great a news, its not a very easy DIY job, but it is do-able if you have some experience and tools.

I have a perminent better solution to this problem. The broken part is out there however, its on "back order". The fix that I have done is to remove the water pump and "punch" out the broken piece from above. Then use a 3/8" pipe thread tap and put threads in that hole. Go to your nearest auto parts house and purchase a "heater hose nipple". Then, with a deep well socket and a long extention, thread the nipple in. Install the hose and clamp it at both ends. You can tap that hole because its cast aluminum.

it could be the freeze plugs. that can be expensive.

i have a 1999 ford explorer v8 5.0 and it is leaking right behind the waterpump. but not from the pump, about 5 inches behind the pump, like by the block, what is it?

there is a bracket attached to the pipe just above the water pump bolts (this bolt looks similar to the water pump bolts). there is also a bracket attached to a long, thin bolt just under the valve covers on the drivers side. you'll need a long socket to get to this one. once those two brackets are freed up, you should be able to work the heater hose out of the hole in the water pump. of course, that metal pipe attaches to a rubber hose about halfway back from the water pump to the firewall, so you'll want to undo the hose clamp that holds it in place and slide the metal pipe out of the rubber hose.

i'm not sure what you have in mind, but this should let you accomplish it. note that there is an o-ring that fits on the water pump end of that metal pipe. it's included when you buy the water pump.

have fun and be careful.