# Coolant Leak between Intake Manifold and Water Pump



## shimelhoch (Dec 9, 2009)

Hello,

I just installed an Edelbrock 2156 intake manifold on a 69 Pontiac Lemans 350 5.7l. I am having a coolant leak from the connection between the front of the intake manifold and water pump. Is there some type of gasket or seal that goes between the front of the intake manifold and water pump? 

I am aware that there is a bolt that helps pull the water pump tight to the intake manifold but am wondering if there is something more I am missing. Attached is a photo of the location of the leak. Thanks to anyone who can help.


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## dimitri (Feb 13, 2009)

There is a donut shaped rubber gasket that goes into a recessed grove on the intake. I like to put RTV on it. You need to have all of the intake bolts loose and tighten this long bolt first. Then tighten intake bolts according to Edlebrock instructions.

I just noticed you are missing the long bolt with heavey t washer that goes into the thread hole at 1:00 position where you are pointing. 

1964-1972 GTO Water Pump Flange Bolt Set - Includes special washer - KR00113

That is a picture of the bolt and special washer you are missing.


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## geeteeohguy (Feb 2, 2008)

Dimitri nailed it again. You need what he said, and you need to drain the cooling system and loosen the intake so you can do the long bolt first.


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## shimelhoch (Dec 9, 2009)

*Thank you Dimitri!!!*

Thank you for the reply. Didn't think to loosen the bolts of the intake which would be why I was having such a tough time getting the bolt to go in. I'll use the RTV also. Thank you again for the reply to my post!


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## BearGFR (Aug 25, 2008)

shimelhoch said:


> Thank you for the reply. Didn't think to loosen the bolts of the intake which would be why I was having such a tough time getting the bolt to go in. I'll use the RTV also. Thank you again for the reply to my post!


:agree Good eye, Dimitri! 

Shimelhoch, in case you need it for reference here's a photo of what it looks like assembled.Bear


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## 6tee7 (Feb 24, 2011)

I think ames selles a thicker rubber washer for that


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## chin (Jan 5, 2011)

Did you notice any difference after you put that manifold on? What carb are you using? I'm running a Rochester 2bbl on a stock 69 350 and just bought a Edelbrock 2156 manifold, 1405 carb, and a changeover from points to HEI. It's all going on tomorrow! Glad I did a search for performer intake and saw this post which shows that long bolt. Good heads up.


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## 1970 Lemans (Jul 25, 2009)

You seem to have coolant collecting on top of the manifold. Is that a result of the leak you mention, or might you also have a leaking thermostat housing gasket?


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## shimelhoch (Dec 9, 2009)

Yes, the thermo housing gasket is also leaking.... Any suggestions on that issue?


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## BearGFR (Aug 25, 2008)

shimelhoch said:


> Yes, the thermo housing gasket is also leaking.... Any suggestions on that issue?


Replace it with a fresh gasket. Make sure you clean every trace of the old gasket off of both the intake and the housing. If the metal on either surface is pitted or rough then you might need to dress it down some with a flat file. Also inspect very closely to make sure the housing and the area around the intake aren't cracked.

Bear


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## 1970 Lemans (Jul 25, 2009)

Yes, over torqueing can cause one to crack the housing. I believe the correct torque spec is 30 ft-lbs. Also, in the past when I did this, I used one of the permatex gasket sealers with the new gasket.


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## shimelhoch (Dec 9, 2009)

Thanks to everyone for your help. No more coolant leaks! Now its on to tuning to get max HP!!!


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## NEEDLEZ (Oct 21, 2009)

Anyone happen to know the length and size of this bolt? I am also having a leak in the same area and realized I am missing this bolt, too. 

I thought if I knew the size and length I could find one at a local hardware store instead of waiting a week to ship 1 here.


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## BearGFR (Aug 25, 2008)

Not off hand, but I'm going to be removing mine "soon" to prepare for a head swap, so if I remember I'll measure it for you when I do. It's ok to "remind" me.

Bear


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## geeteeohguy (Feb 2, 2008)

It's a special bolt, with a flanged head. I believe it's 5/16x18 (NC)...and about 3" long. Been awile. You can use a generic bolt, with a washer, but the "right" bolt is an odd duck, and uses a specially shaped and contoured washer. Bear, good luck with the head swap. Hope you get it done for your tour.


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## ryukyudiver (Oct 2, 2013)

*Intake mani/timing cover seal*

I know its an old thread however, I also have the same inake manifold. When I installed the packing from the edelbrock kit I noticed it is too thin for the Pontiac Performer intake, even if you use High Temp RTV. Before installing the intake mani, make sure the packing stick out of the recessed groove enough to make a seal. If it doesn't start looking for a thicker one.

Chris

'68 LeMans
'75 5.7L


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## dfcex59 (Mar 19, 2017)

I have a leak coming from the water pump bolt hole at 12:00.
It started when I tightened the bolt (over-tightened?) It seems like I went through a water jacket or something. Maybe the bolt I used was too long?
I guess I'll pull the water pump and see what this looks like.
Dan


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