So basically this water pipe has had me at my whits end. It leaks, right where the o-ring is where the water pipe mates with the thermostat housing. I have an hx40 and had to dent the pipe to make it fit. Its seems obvious that this is why its leaking. I just bought a new water pipe and even that is leaking. I know that this is a pretty common problem with the 7 bolt water pipe. Does anyone have any suggestions for a solutions? Im going to get the pipe welded to the thermostat housing tomorrow but im just wondering if anyone else has done anything different.

Why not just replace the o ring?

Just replace the O ring, If it doesn't work, get a 1g pipe with the thermostat housing and you will be ok.

jpmxrider489 said:

Why not just replace the o ring?

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+1

Sounds like you have some bad O-Rings.

STM: OEM MITSUBISHI WATER PUMP PIPE O-RING | EVO VIII-IX | 90-99 DSM | MD030764

WES_393 said:

+1

Sounds like you have some bad O-Rings.

STM: OEM MITSUBISHI WATER PUMP PIPE O-RING | EVO VIII-IX | 90-99 DSM | MD030764

Click to expand...

I forgot to mention that I already replaced both o-rings on another note will a 1g water pipe and thermostat housing bolt on to my 7 bolt head?

yes, it will bolt on,

HMMMM I might have to do this to my 2g also since Im deleting A/C and the heater.

Have you checked to make sure there are no uneven surfaces or trash blocking the O-ring from sitting correctly in there? You could try re-seating it with a little RTV.

Maybe try a thicker diameter o-ring. Just an idea. Might be a pain to push back into the water pump and thermostat housing, but would be well worth it if it worked.

A few years back I had a leak where the front water pipe connects to the water pump. It turns out the o-ring had turned rock hard in just a couple of months. I got a new o-ring and, although not recommended, used a bead of RTV as well. It sealed up fine, but just made it hard to separate the two during the last timing belt and water pump change.