Descripton and source for seal around heater core inlet/outlet tubes; 1970 with AC

[Mark E.]

What type of seal (if any) is used around the heater core inlet and outlet tubes? (See first two photos; 1970 with AC.)

Recommendations where I may find one? I purchased a seal from a vendor (see last two photos) which I thought was for this purpose. But it's not the right size or shape. I was expecting a seal with two holes to accommodate the tubes.

Where is this shown in the AIM? I couldn't find it within five minutes of looking.

Thank you!

[Gary B.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

Mark, I don't think there is one used. I think it's open to the elements.
I looked through some of my photo's and the couple I have show no seal. Both are of low mileage original unrestored cars.
Maybe somebody will post a picture that does.
Gary Bosselman

[Joe L.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

What type of seal (if any) is used around the heater core inlet and outlet tubes? (See first two photos; 1970 with AC.)

Recommendations where I may find one? I purchased a seal from a vendor (see last two photos) which I thought was for this purpose. But it's not the right size or shape. I was expecting a seal with two holes to accommodate the tubes.

Where is this shown in the AIM? I couldn't find it within five minutes of looking.

Thank you!

Mark-------


A seal was used. It was foam rubber and it did have 2 holes for the core tubes. It was GM #3909099 but it was never available from GM in SERVICE. However, Dr. Rebuild, as usual, offers a PERFECT reproduction.

Of course, the core has to be removed in order to install the seal.

[Mark E.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

Thanks Gary and Joe.

I was thinking the seal would be visible and able to be installed by pushing on to the core tubes.

Is it? Or is it possible the seal is already installed but not visible from below?

[Joe L.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

Thanks Gary and Joe.

I was thinking the seal would be visible and able to be installed by pushing on to the core tubes.

Is it? Or is it possible the seal is already installed but not visible from below?

Mark------

Actually, I was referring to the non A/C heater core seal. I thought the with A/C was the same but it may not be. However, I can see the seal on the photo on the right and, from what I can see of it, it appears at least similar to the without A/C seal. It's very possible the seal you purchased is correct for with A/C. In any event, I don't think the seal can be installed without removing the heater core. For without A/C applications I am certain it cannot be replaced without removing the core.

[Mark E.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

Thanks Joe.

Should I be able to see the seal if it's in place by looking up from the bottom?

Is running the blower on high then checking for air loss around the tubes a good way to check if there's an air leak?

Other ways to check without removing the core?

[Joe L.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

Thanks Joe.

Should I be able to see the seal if it's in place by looking up from the bottom?

Is running the blower on high then checking for air loss around the tubes a good way to check if there's an air leak?

Other ways to check without removing the core?

Mark------

I think you should be able to see the seal from the bottom. I don't know if the method you suggest would be effective at checking for an air leak but it sounds like it might work.

Attached are 2 photos of the Dr. Rebuild seals for the application. For seals, the Doc will always get it exactly right. He's the uncontested "King of Seals".

[Mark E.]

Re: Descripton and source for seal around heater core inlet/outlet tubes; 1970 with A

Thanks Joe. Your photo is the seal I got from Dr Rebuild. I don't see it on the car, so it's either missing or not visible when installed. I appreciate any input about this.

I was expecting a seal with two holes that go around the tubes. Otherwise, I don't understand how the seal would fit properly.