pissed
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,107
Likes: 0
From: RI
pissed
I found a leak after filling the cooling system and I can't quite figure out where it is from. I thought it was from the coolant temp sender on the pump but after installing, it was dry. It feels like it was coming from the back of the pump. So I removed all the hoses, drained the coolant (which I swore a few time because I knew some antifreeze was going to get on my new opti. Now I'm going to go through the process again.Stop me if I'm doing something wrong
1) use more permatex silicone around freeze plug on pump (I'm using e-pump)
2) use permatex the right stuff to seal the meziere to the pump housing (along with provided O-ring)
3) use permatex slightly around pump openings at the block and the pump itself, sandwiching the new gasket
4) install new temp sendor (straight from AC Delco)
what about hoses?
1) use more permatex silicone around freeze plug on pump (I'm using e-pump)
2) use permatex the right stuff to seal the meziere to the pump housing (along with provided O-ring)
3) use permatex slightly around pump openings at the block and the pump itself, sandwiching the new gasket
4) install new temp sendor (straight from AC Delco)
what about hoses?
Pro
Joined: Feb 2006
Posts: 688
Likes: 0
From: Concord NC
well if its not your hoses, your waterpump, your resovoir, radiator cap, RADIATOR, or your coolant sensors. Wow thats just about everything there is. Is the leak on the top or bottom? Any additonial information would be helpful. 
Pro
Joined: Oct 2005
Posts: 721
Likes: 1
From: Charlotte NC, behind someone going 10 under the speed limit
Those pumps can be a pain to set on the block with the 6 bolts keeping the gaskets from sliding. I use weatherstrip adhesive to hold them. I don't know if the LT needs thread sealer on the pump bolts or not, maybe this is it? Some pumps include gaskets without the sealing beads pressed onto them like GM's do, sometimes they leak.
Melting Slicks
Joined: Oct 2000
Posts: 3,426
Likes: 4
From: Heidelberg PA
Cruise-In V Veteran
There is allways the possibility that the meziere is leaking internally. The first time I installed my meziere pump there was an anti-freeze leak that drove me crazy. It ended up being the pump. The antifreeze was leaking internally and leaking out the back of the pump. Meziere did fix it, so all is good.
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,107
Likes: 0
From: RI
the meziere felt dry. I took it off and put new silicone down. It felt as if it was coming from behind the waterpump. like the weephole underneath or from the freezeplug I added (but it had silicone).So after taking the meziere off, I added some more silicone to the inside of the freezeplug and added a boatload to the rear. I also put more at the little weephole underneath. I've decided to buy a new sensor new hoses, new gaskets. Now I just need to make sure that the driver lower waterpump bolt seals properly. I really hate how GM designed the block where that bolt when removed expells antifreeze 
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Instructor
Joined: Jun 2004
Posts: 175
Likes: 0
From: Phoenix AZ
My mystery leak turned out to be at the valve to the heater - was so slight I assumed it to be from the overflow and I kept geting air in the system so I knew something was F***'d up. Then found a trace of antifreeze on the frame just below the heater valve. Low and behold there was a drop on coolant on the bottom of the valve. That also cured a weak A/c condition and a vacuum leak that threw the range/mileage displays off too.
