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Checker Radiator Repair - Part 2

Copyright 2015 - Checker Car Club of America

First put the radiator back into the car. You may as well also replace the yoke that holds it down and bolt it in as it helps to keep the radiator from wiggling. Leave the two 45 degree transmission tube fittings off for now.

Put the new thermostat into the hole in the top of the block and put some silicon sealant on one side of the gasket all around its perimeter and put the gasket over the thermostat. The “pointy” side of the thermostat faces into the engine block with the spring side pointing up. Put some more silicon all around the perimeter of the top of the gasket and carefully put the thermostat housing over the thermostat and gasket. Replace both bolts and tighten. Below is a shot of the thermostat and gasket in place on the engine block before putting on the housing.


Using the old heater hoses as a template, cut three new ones of the same sizes. Put two clamps on each one. Make sure that when you slide the clamps into position that they are positioned so you can easily reach them to tighten them. I do a test before I even insert the hoses to make sure the loose clamps are facing the correct way, as they are loose on each hose.

Insert one long heater hose into the fender side of the heater outlet in the firewall and clamp it, making sure the hose is inserted so it touches the firewall and that the clamp is pretty close to the end of the hose when tightening it (this holds true for all clamps: make sure they are as close to the end of the hose as possible).

Insert the other end of this heater hose to the opening on the top of the water pump next to the fan. Note that the hole on the water pump is a 5/8” fitting for some reason so you really have to work on this 3/8” hose onto this larger hole or jury-rig a hookup with two different sized hoses here. If the temperature you are working in is cold the hoses are harder to insert into the openings, especially this one.

The second long hose connects at the bottom of the heater control valve attached to the firewall above the heater core holes and connects at the hole just to the left of the thermostat housing on the top of the engine block.

The third heater hose, the short one, runs from the front of the heater control valve to the second hole going to the heater core on the firewall beneath this control valve. Position and tighten the clamps for these hoses. Below is a photo of the heater valve on the firewall with one of the new hoses attached to it.

Heater Valve

Now do the top radiator hose, making sure the clamps are loose on the hose in the correct position for tightening when done. Note that though the radiator hoses you took off your car may have been preformed in a correct curve, these are hard to find now and the ones I gave you numbers for are “flexible” hoses that you bend into position. This doesn’t make too much difference for the top radiator hose but does for the lower one. If you can find preformed hoses go with those and let us all know the numbers.

The bottom radiator hose is tougher to do. It helps if you can securely jack the front end of your car at this point as you can really only put this hose on from underneath the car. I bend it first a full 90 degrees, trying not to crimp it at the bend (a little crimp seems to be OK as mine is crimped a bit). Then put the two clamps on loosely and in the correct position to be able to tighten them (the top one should be above the bend as it will not want to easily slide across it).

I attach the hose to the bottom of the radiator first and clamp it on; making sure the clamp is as close to the metal of the radiator as possible (otherwise it will leak here). Then I put the top of the hose into the engine opening (which for me wasn’t easy) and position the clamp as high up the hose as it can go and still be on the rubber and then tighten it.

Now you will need to reattach the transmission lines to the radiator. This was the hardest part of the project for me and I will detail all my trials and tribulations so you have full disclosure before you begin this project.

This is also where having the front end of the car securely jacked up a bit helps as you have to do all this from underneath the car. First, insert those 45-degree Male Elbow fittings in both the holes at the bottom of the radiator using a little pipe dope on the threads and an open-end wrench. Tighten them with the wrench pretty tight so the angle of the opening is roughly perpendicular with the radiator. The way they sit or point when tightened depends somewhat on the angle that the transmission lines come in (to be discussed later). If you had to cut the transmission lines, you next insert the end part of the saved transmission line or the new end part of the Poly Arm if you are replacing the stub of the transmission tube with it, into this, again using some pipe dope on the threads, into these 45 degree Male Elbow fittings using an open end wrench. Below is a shot of this fitting attached to the radiator without the transmission line attached yet.

45 Degree Male Elbow Fitting

The way these pipe fittings work is that they either have a flared end, like the original transmission tube has, then is pressed against the fitting on the radiator when the cap is tightened. If you are using a new stub tube, the ones I bought had a flared end on each side and a cap on each side. However, you have to cut this Poly Arm extension with your pipe cutter to the correct length to match up with the transmission line that you cut. When you do so you have one end that is flared (which I attach to the 45 degree Male Elbow fitting on the radiator) and one end that is not flared, which is OK.

After this new line is attached to the radiator you have to connect its other end with the end of the transmission line (which is not flared either as you cut it). This is where a Union Connector is used. Note that these Union Connectors have five pieces to them: the center piece that both ends of the transmission line are put into, two fat rings (that substitute for the flared ends of the tubes), and two caps that attach the two lines (and rings) to the center piece to make the connection or splice. So first the caps are put on each transmission tube piece, the new one and the old one, then the fat ring on each pipe. Below is a shot of all the connector pieces.

Connector Parts

Note that both the cap and ring will not want to easily go onto the new Poly Arm end so before you get to this point I suggest sanding down the end of the pipe and getting them to fit at least loose enough that they can move up and down the pipe some. You might as well attach this end of the connector to this stub pipe before you crawl under the car as it will be one less thing to tighten while on your back.

Put some pipe dope on both threads and then attach the caps onto the connector and tighten using one open end wrench to keep the center piece still and another open end wrench to tighten the caps on either end.

When you tighten the caps, the fat ring will get pressed against the connector and the cap and will squeeze the tube a bit, becoming a substitute for the missing flared end of the pipe. This should make a good seal to keep the transmission fluid in when tightened.

This is where I encountered the only problem with the whole job. Both ends of the spliced transmission lines must be exactly lined up for them to thread properly. This will not happen automatically and you are also lying on your back working above your face on this project. If you are not immediately successfully in threading the cap to the connector, stop and take a look at how things are lined up. If you can see that the transmission pipe is not going into the connector nice and straight, you are never going to be able to get the cap to tighten and if you do you will probably strip the threads (and have to get a new connector and start again). The transmission lines do not necessarily come in at a true 90-degree angle to the radiator here.

This is probably why they have that 45-degree Male Elbow fitting as you can adjust this fitting some to line up the angle to the transmission line. So determine which way the Male Elbow fitting should be turned to and try making the connection again. This took a lot of adjustments, patience and replacement fittings (as I often stripped the threads thinking I was connecting them). Once you can get the cap on, tighten it using two open-end wrenches. Repeat with the other transmission line if you had to splice that one too. Below is a shot of the spliced transmission pipe with the connector.

Spliced Transmittion Pipe

If you were able to disconnect the two transmission lines from the radiator without having to cut them, you may still have trouble setting the 45 degree Male Elbow in the correct position to attach the fitting on the end of the transmission line. I tried and could not do so and eventually had to cut this pipe also and use half of a Poly Arm to connect it using a connector like on my other side. If you can connect it great; one less thing to do. You may have to turn the 45-degree Male Elbow on the radiator some with your open end wrench so that the transmission line goes straight into it to screw it on. If it doesn’t screw on then you have to probably make this adjustment. I stripped two Male Elbows trying to do this before I gave up and did the splice approach.

At this point you are done connecting the re-cored radiator.

Next you reattach the pipe from the coolant capture tank attached to your inside fender to the fitting at the radiator opening.

[By the way, I replaced the two hoses connected to the capture tank while I was at it but it probably wasn’t necessary to do so and so I didn’t discuss it here at all.]

Now you have to refill it with coolant and check for leaks. Though this is the easiest part of the job, it takes the longest since this is when you completely flush the engine block and heater radiator of old coolant, which can only be done by repeated dilutions and drainings. Your engine block and heater radiator still has about half the car’s capacity of coolant in it even without the radiator’s coolant. I took a whole day doing this step while I was doing other things. Below is the installed radiator without the yoke attached over it to secure it to the mounting.

Reinstalled Radiator

I filled the radiator with water from the tap and then, with the new radiator cap on (to create pressure for testing the hose connections), started the engine and let it run ten minutes or so. You want the engine to heat up so that the thermostat opens and cycles the coolant in the engine block and heater to the radiator. Make sure you have your heater set on high inside the car to cycle the coolant in the heater radiator under the dash as the same time.

Be careful and wear safety glasses or goggles when looking into the engine compartment with the engine running. If your transmission lines were not tightly hooked up to the radiator, transmission fluid may be squirting out and the radiator fan will blow it into the air and into your face! Can you tell I learned this from experience? If that is the case shut down the engine and crawl underneath and tighten the leaking line some more.

Once you can feel the heat from the radiator or heater hoses you can presume that the thermostat opened and cycled coolant through the new radiator. Turn off the car for at least an hour. When you can tell that everything is cool to the touch, open the radiator cap (I always do so with a large towel just in case I was wrong and it is still hot and starts to boil over.) Then drain the coolant in the radiator into a bucket by loosening the plug on the bottom left like you originally did.

The reason to keep the radiator cap on the first time is to increase the pressure to see if there are any leaks. I had a leak at the thermostat housing and at the lower radiator hose where it was inserted into the engine block (because the clamp was too low on the hose and had to be shoved up further). All easy fixes.

After each warm up and flush I went around and tightened all the hose clamps as heat will loosen up the rubber and allow a tightening of the clamps. It was amazing how I could tighten each one a bit more after each flush.

I repeated this flushing process a number of times until I could not see any yellow/green color in the bucket, which meant that all the old antifreeze was gone and only water was in the radiator and engine. I also looked underneath the car for any drips or puddles of coolant and this would indicate a leaking fitting. At one point I added a Prestone Radiator Flush solution to it though I do not know if this is a good thing to do or a bad thing (but I had one around so used it). When I was getting close to this point I started filling the radiator up with distilled water so that when I was ready to add antifreeze I could be comfortable that most if not all the water in the radiator was distilled water and not tap water. This is a judgment call and is not critical. I used a large 2.5-gallon jug of distilled water.

The last step is to drain the radiator one last time then fill it up with concentrated antifreeze. The car’s manual says that it took 17 quarts of total coolant with the V-8 engine in 1982. My car has a larger replacement 350 cubic inch V-8 in it so I am not sure what capacity it would be with that engine but it would just be a bit more. Of course, at least half this amount is in the engine block and radiator heater, which should all be distilled water by now.

The bottom line is that you need to fill the drained radiator with straight, concentrated antifreeze. When this is mixed with the water in the engine block up, you will end up with a properly diluted coolant mixture in your engine, enough to protect it from freezing in the coldest climates. This,of course, is the main reason why we use antifreeze in the first place.

After filling the radiator with antifreeze (mine took almost three gallons), I started up the engine again but this time left the radiator cap off. When the engine warmed up and the thermostat opened, the radiator will “burp” and might overflow some fluid. This is fine as you are getting the air bubbles out of the system. I let the engine run a good 15 minutes or so without the radiator cap on so it cycles the coolant through a few times to get all the air out. I had to top off the radiator with quite a lot of antifreeze in this process as the air was displaced. You can see the cycling of the coolant when the thermostat opens up when looking into the radiator at this point.

After awhile I put the radiator cap back on and let the engine run five minutes longer, again looking for leaks from the hoses where they were clamped on to fittings. Then I shut it down.

The last step is to make sure that your dilution of water and antifreeze is strong enough to keep the coolant from freezing in the coldest possible weather your car is subject to when not running. In Detroit this past winter we woke up one morning to the temperature being a record minus 17 degrees. It happens and I was glad that my antifreeze solution was protecting my radiator to minus 25 degrees. You can purchase a little suction tube to check the freezing point of you coolant. When the car is cool you open the radiator cap and with the tool suck out some of the coolant. In the chamber of the tool are little balls. The number of balls that float to the top in the coolant mixture tells you the freezing point of the coolant. Mine right now is minus 40 degrees, which is probably too much antifreeze in the mix. If I wanted to correct it I could just add distilled water to the overflow coolant tank under the hood and that would eventually mix with the coolant in the radiator and dilute it some. The antifreeze also increases the boiling point of the coolant, which is advantageous, but you do want a distilled water/antifreeze mix instead of just all antifreeze as your coolant in order for your car to run at a proper temperature.

My radiator had a sight glass on the top right side of it. Ferndale Radiator cleaned it off for me when they re-cored the radiator. This allows you to see the level of the coolant in the radiator. It really isn’t necessary when you have the coolant overflow tank under the hood as you can check the level looking at that now a day. But Mel suggested not filling the radiator to the top but, instead, just until you can see the level in the sight glass and forget about putting any coolant in the overflow tank. I am trying that for now but I do have the overflow tank all attached like before. Below is a photograph of the sight glass on the radiator.

Radiator Sight Glass


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