TR2/3/3A TR3B Anti-Freeze Change

[af3683]

I'm looking to change the anti-freeze in my TR3B and would appreciate some assistance:

When draining is it best to just disconnect the lower radiator hose as opposed to opening the petcock ? I don't want to take a chance in breaking the petcock.

Should I open the heater valve on top of the engine ? I've never touched it and I'm not actually sure if it is in the open or closed position. I can't turn it but I think that's because the nut at the bottom must be loosened first.

Any idea how many quarts of anti-freeze are in the cooling system ? I'll be changing it in my garage and want to make sure I have a large enough container to hold the the old anti-freeze.

Any recommendations for the new anti-freeze ? Some many different kinds.

Thank you for your assistance.

Art

 

[bobhustead]

Use the lower hose at the radiator. There is a book you can google called "Practical Hints" to get capacities of cooling system and much more. Select the yumpu.com hit for access.
Bob

 

[charleyf]

If you are interested in doing it the hard way. By all means remove the radiator hose. For me the drain petcock works just fine. Yes open the heater valve. In addition you need to open the drain on the passenger side of the engine. It is located above the starter. Be prepared for a mess as this drain is difficult to capture what drains out.
Neither my car or myself are sophisticated enough to use anything but a good quality regular antifreeze. 50 /50 mix 2 gallons total.
Charley

 

[CJD]

Don't forget the block drain over the starter motor. You will likely have to pick the crud out to get it to drain.

 

[NutmegCT]

Art - here's the TR3 Practical Hints booklet:

https://tecb.eu/onewebmedia/TR3A_owners_manual.pdf

I don't know the heater valve on your 3B, but on my 3A there was no "locking nut" - just a T handle at the top, to turn for open/closed.

Tom M.

 

[af3683]

Thank you all.

Tom, attached is a photo of my heater valve. I'm not sure if it is currently in the open or closed position as I never use the heater and don't know the condition of the heater core. I don't want any problems. I would think it is closed but that is just guess on my part. I'll probably pickup 2 gallons of the Prestone Ready to Use 50/50 anti-freeze and drain the system by removing the bottom radiator hose. Hopefully I'll be able to get my hand under the radiator and remove the clamp and hose without too much of a problem and spillage as I'm recovering from shoulder surgery.

Art

 

[NutmegCT]

Art - as I remember, turning that knob all the way counter clockwise opens the valve; all the way clockwise closes the valve. If you look at the stem, you see a shinier bottom half, which to me would indicate the valve is open.

 

[af3683]

Tom,

That's a good point! So to open or close the valve you first loosen the nut, then turn the valve to open or close, and then lock it in place with the nut. Seeing that you are also in Connecticut (I live in Guilford), I'm curious if you have your heater valve opened or closed. Thanks again.

Art

 

[charleyf]

Tom,

That's a good point! So to open or close the valve you first loosen the nut, then turn the valve to open or close, and then lock it in place with the nut. Seeing that you are also in Connecticut (I live in Guilford), I'm curious if you have your heater valve opened or closed. Thanks again.

Art

NO do not touch the nut. It works just like the hose bib on your house. Only turn the handle. Open or closed.
Charley

 

[af3683]

Thanks Charley. When filling the radiator back up, do you fill it to the top, start the engine and wait until the thermostat opens and the level drops, and then add more coolant to the point where the coolant is about 1/4 inch from the bottom of the neck?

 

[charleyf]

Thanks Charley. When filling the radiator back up, do you fill it to the top, start the engine and wait until the thermostat opens and the level drops, and then add more coolant to the point where the coolant is about 1/4 inch from the bottom of the neck?

Yes, except the coolant level should be about 1/2 -3/4" below the neck. You need room for expansion. Otherwise it just spits it out the overflow. Do not be concerned if you do not use all of the 2 gallons.
Charley

 

[af3683]

Thanks. But if its 1/2-3/4" below the neck piece that sticks out of the radiator, I won't really be able to see anything in the neck? Maybe I'm missing something.

 

[bobhustead]

The neck is the round thing that holds the radiator cap, not the box it is soldered into. For ease of removing the bottom hose, if it resists your hand, you can use a large pair of channel locks to gently grip and twist the hose.
Bob

 

[charleyf]

The neck is the round thing that holds the radiator cap, not the box it is soldered into. For ease of removing the bottom hose, if it resists your hand, you can use a large pair of channel locks to gently grip and twist the hose.
Bob

+1 for the base of the radiator cap is what I call the neck.
Charley

 

[CJD]

The nut under the heater valve tightens the packing that seals the stem. Only tighten that nut if the stem starts leaking.

In the TR's I have owned, if I put more coolant in than it likes, it just spits it out on the first drive. They seem to like just enough to be able to see coolant when you look into the cap opening...so the neck is mostly air.

 

[af3683]

I was planning on using Prestone 10 year Ready to Use anti-freeze/coolant (yellow). I was wondering what others use. I'm certainly no expert but I've read that Prestone yellow is OAT and is not always recommended for use in old cars. Some say that you should use IAT (green) like Zerex. Just wondering what others use. Thanks again.

Art

 

[RJS]

I've used Prestone green for 22 years. No issues. Drain and refill every other year, 50/50 with distilled water

Bob

 

[ckeithjordan]

+1 to Prestone Green

 

[af3683]

This one? Do you use it because it is the old IAT formulation ?

 

[RJS]

This one