waterpump - heatercore

[wolfman98]

When I got the car the heatercore had been bypassed and i assume because it is no good , though i have not tested it yet. the way he had it set up is that he had a hose coming out of the waterpump ( the closest exit tube in photo ) this hose was split into a "Y" with one going into the top of the block in the rear passenger side and the other going around the manifold and into the block in the bottom front passenger side. my question is 2 part and that is if the heatercore is rotten I am not going to replace it this year as I only plan on driving in warm weather. Is this a good setup cause when I pulled the bottom inlet out nothing came out as it was completely blocked ( I had to dig it out with small screwdriver ). If the heatercore is ok I will hook it up , what is the correct routing for this setup? Check out the waterpump , does it look like that nearer outlet tube was added?

[ent72olds]

Looks proper to me. I believe there are 2 hose sizes there, 5/8" & 3/4". By measuring you shoud be able to know which outlet goes to which pipe on heater core. The bottom pipe on the core goes to the intake, and the top goes to the w/p.

[wolfman98]

If the heatercore turns out to be bad does anyone know if I need to route it the same way as it was? Do I need to "Y" the hose coming out the waterpump and split into the top and bottom of the block?

[rocketraider]

No. Run the heater hoses like Erik said. You have a standard issue 1965-73 Olds waterpump, with the top nipple for the thermostat bypass hose, and the near one for the heater return.

1974-later pumps do not have the heater return nipple. Those years routed the heater return hose straight back to the radiator cold side tank. Part of a factory fix to reduce heater gurgle and moan noises.

Heh. You should see the interim fix they put out in mid-73.


Wolf, do you have a factory chassis service manual? You'll need it to R&R that heater core.

[bigoldscruiser]

The bottom front passenger side connection sounds like they put a hose nipple in place of the block drain plug. I don't see the advantage of that. Without the heater core, you just need to connect the top rear intake port to the water pump port. The problem is - the rear connection is 5/8" and the water pump connection is 3/4".

[wolfman98]

Originally Posted by rocketraider

No. Run the heater hoses like Erik said. You have a standard issue 1965-73 Olds waterpump, with the top nipple for the thermostat bypass hose, and the near one for the heater return.

1974-later pumps do not have the heater return nipple. Those years routed the heater return hose straight back to the radiator cold side tank. Part of a factory fix to reduce heater gurgle and moan noises.

Heh. You should see the interim fix they put out in mid-73.


Wolf, do you have a factory chassis service manual? You'll need it to R&R that heater core.

ok here is what I got with the car....Fisher Body 1969 service manual...1969 Olds chassis sevice manual...1969 Olds new product service information manual 901....1941-1975 Olds parts & supply catalog 1999 edition and I have Fuisck Olds online catalog

[wolfman98]

Originally Posted by bigoldscruiser

The bottom front passenger side connection sounds like they put a hose nipple in place of the block drain plug. I don't see the advantage of that. Without the heater core, you just need to connect the top rear intake port to the water pump port. The problem is - the rear connection is 5/8" and the water pump connection is 3/4".

That is what confused me. I did not understand why he had the "Y" joint one to the top and one to the bottom. I should be able to find a solution for the fitting glich. thanks

[wolfman98]

I found the chassis manual and dusted it off , I found out exactly how it should be set up with the heater core. Out of pump to top inlet into core the out bottom outlet into top rear of block. If I find the heatercore is rotton then i will route from pump to rear of block. I will have to get the drain plug to block off the bottom inlet he added to the bottom of the block. I have the original chassis service manual printed in 1968 and as I plan on draining tranny and changing gasket , seals and strainer I have all the info on how to do it step by step. Thanks for responses and I should have looked to see all the books I got with the car , they were in a box in the trunk and I took it out and stored it away . I had the fisher body service manual cause he had it on top then some extra material samples and folders with reciepts on the work and parts he bought , then some original Youngmobile thinking 1969 , S.G.I sales transfer info sheets etc. The chassis manual was on the bottom and is amazing how much info it contains , it should be a huge help finding parts and #'s I need.

[citcapp]

I like your thread, you answer most of your own questions providing good information as you do along. Keep up the good work

[joe_padavano]

Originally Posted by bigoldscruiser

The problem is - the rear connection is 5/8" and the water pump connection is 3/4".

To be honest, all I've ever done in this situation is to put the 3/4" hose over the 5/8" fitting and crank down on the hose clamp.

[J-(Chicago)]

Originally Posted by joe_padavano

To be honest, all I've ever done in this situation is to put the 3/4" hose over the 5/8" fitting and crank down on the hose clamp.

I do that most of the time as well.
One time however, I actually used Rtv and a 1'' piece of smaller hose and managed to mush it all in there for a tight fit before clamping.

[Lady72nRob71]

Originally Posted by wolfman98

If the heatercore turns out to be bad does anyone know if I need to route it the same way as it was? Do I need to "Y" the hose coming out the waterpump and split into the top and bottom of the block?

My instincts would have been to cap off both of the heater hose connections - the one on the pump and the one on the heater valve (or top left rear of the block). I figured if the heater water valve shut off the flow when the heater is off (at least on A/C cars), then that flow path is not really needed.
Also, every Olds water pump I had bought came with a rubber cap to cap off the heater connection if you did not need it...
Also, if you do have a hose going to a block drain plug, I would get rid of that pronto...
(Looks like you already did that - glad you had the manuals.)
To me, fewer unneeded hoses are better.

Someone correct me if my instincts are wrong.

[wolfman98]

that is what I will probably do just to make it look better. Any suggestions for good hose clamps.

[rocketraider]

The chassis manual was on the bottom and is amazing how much info it contains , it should be a huge help finding parts and #'s I need.

That's what I keep trying to tell y'all!