New Water Pump Leaking (when filled with coolant)

Been doing a bunch of stuff on my 87 TC (aux shaft, distributor, timing belt, water pump, hoses and thermostat)… was finishing up and added the coolant and noticed some dripping from the upper radiator hose, so tightened up the clam a little more and that seemed to stop the leak when I noticed another drip which is coming from the water pump to block gasket.  This is a new water pump (bosch) that I had picked up years ago (funny how parts accumulate) and I did use the gray water pump gasket material on both sides of the gasket and on the bolts.  This is the first time I ever had an issue like this.

I disassembled and didn't notice anything unusual.  Got a new gasket and will try that tomorrow.

I'm thinking perhaps I didn't use enough gasket maker or maybe overtightened the bolts.   I'll clean off the surfaces and try again with a little more gasket material and torque the bolts this time to the 14 - 21 ft lbs specified.

Just venting a little...  If it leaks again then I will assume the pump may be bad but when checking the surface it does seem straight.

Figures since everything was going smoothly and only had the plugs and intercooler left

Anyone encounter this type of issue before?  It's a new one for me!

Been doing a bunch of stuff on my 87 TC (aux shaft, distributor, timing belt, water pump, hoses and thermostat)… was finishing up and added the coolant and noticed some dripping from the upper radiator hose, so tightened up the clam a little more and that seemed to stop the leak when I noticed another drip which is coming from the water pump to block gasket.  This is a new water pump (bosch) that I had picked up years ago (funny how parts accumulate) and I did use the gray water pump gasket material on both sides of the gasket and on the bolts.  This is the first time I ever had an issue like this.

I disassembled and didn't notice anything unusual.  Got a new gasket and will try that tomorrow.

I'm thinking perhaps I didn't use enough gasket maker or maybe overtightened the bolts.   I'll clean off the surfaces and try again with a little more gasket material and torque the bolts this time to the 14 - 21 ft lbs specified.

Just venting a little...  If it leaks again then I will assume the pump may be bad but when checking the surface it does seem straight.

Figures since everything was going smoothly and only had the plugs and intercooler left

Anyone encounter this type of issue before?  It's a new one for me!

There is a more “permanent” thermostat gasket (made by Permatex I believe) available from NAPA, amongst others. It’s not really permanent as I just got a new one when I flushed out the coolant a few months ago, but it is WAY better than the standard paper one. Mine last a couple of years before they are worn to the point that I think replacement is a better option, but I might just be overly cautious.

No sealant necessary or even recommended; just install between the thermostat housing and engine and torque until it “feels right” (14-21 lbs).

I have that gasket, they do work well but are quite a bit thicker...  The bolts for the thermostat are pretty short as is so I did get some longer allen head stainless bolts and also used a lock washer since the sizes I have were either a little too short or too long.  Using a replacement housing where the flange is quite a bit thicker necessitated different length bolts.  Everything is all sealed up, no leaks, passed smog so I'm good to go.  Just need to get the slight pinging sorted out...

I have that gasket, they do work well but are quite a bit thicker...  The bolts for the thermostat are pretty short as is so I did get some longer allen head stainless bolts and also used a lock washer since the sizes I have were either a little too short or too long.  Using a replacement housing where the flange is quite a bit thicker necessitated different length bolts.  Everything is all sealed up, no leaks, passed smog so I'm good to go.  Just need to get the slight pinging sorted out...

Well that’s good news, happy to hear it’s all fixed. Good luck with the pinging—are you referring to valve noise?

Yes, detonation... very slight, timing is set at 8 btdc running premium....

Have a new/rebuilt VAM, inlet hose from vam to turbo is good, new plugs, distributor (ford) and tfi (motorcraft)… think it's real close as it doesn't ping all the time. I'll check the fuel pressure again (kirban afpr) and maybe take a little more timing out. Fuel injectors were cleaned and flow tested not too many miles ago but the car has been sitting a lot for the past 8 months but does have fresh gas. running a boport head with the 2.5 cam, everything else is stock. Have an adjustable cam gear and will try retarding that a couple degrees. Could be it's just too hot (temp was 109 today)…

I'll check the vacuum and fuel pressure in a day or two..