TR2/3/3A Cooling System Flush

[mgedit]

Bit the bullet and removed nose from TR3 today and pulled the rad to either recore or replace. Rather dismayed at the brown mess that was my new antifreeze solution 200 miles ago! With the rad out what is the best way to flush the system?

I was thinking that I need to remove the block plug and flush system with clean water till it is runs out clear. Guess in top hose and out bottom hose ... is that correct? Was going to isolate the heater and drain and flush that separately using passive flow (pour water though a funnel into heater hose) rather than using a garden hose to ensure not too much pressure in heater core.

Anything else to consider? Seems flush solutions get mixed reviews and not sure if they would be useful with system apart.

Cheers, Mike

 

[TR3driver]

By "block plug", do you mean the fitting in the side above the starter? That is normally a valve, and yes you should flush until the water runs clear from that port. If it's that bad, you may need to dig inside with a screwdriver or bent coat hanger.
You'll need to remove the thermostat, and then it doesn't matter which way you flush. In fact, I like to alternate as sometimes that will shake a little more crud loose. I've also been known to adapt a garden hose to the port where the heater valve normally goes (easy for me since I don't have a heater) and force water through both ways from there.

There are (or were anyway) two basic types of flush solutions. The "good stuff" appears to no longer be available in the US, but might still be available in Canada. It always comes in two parts, a strong chemical to attack the rust, plus a neutralizer to be sure it's all gone afterwards. The single part solutions are pretty much useless, IMO.

Good idea on doing the heater separately. I ruined one once trying to flush it with a garden hose.

 

[mgedit]

Thanks again Randall. Sorry, yes the drain tap above the starter. Likely should try to protect the starter from a soaking in antifreeze and rusty water as well. Thought after I posted that removing the thermostat would be a good idea.

Unlikely to find anything very caustic here either.

Yep, been there done that ... I ruined a heater core as well trying to run a hose though it.

Cheers, Mike

 

[sp53]

I have had good success with having the radiator cleaned by having them remove the top tank and use metal rods to clean out the channels and then they solder the tank back on.

 

[mgedit]

Yes, heard of that rodding out solution as well. Right now trying to find a local rad shop that does such work. Cheers, Mike

 

[TR4nut]

Mike- your brown mess, does it appear to be corrosion related only, or did you have some type of fluid compatibility issue? The reason I ask is that this topic came up recently in my club, and with some research I found a wide variety of theories out there concerning the different antifreezes available and their relative compatibility. I think the correct answer is most of these products are compatible with each other but I was wondering if you thought otherwise.

Randy

 

[TR3driver]

At this point, I will never take a radiator to a shop again, without insisting that they rod it out. The shop I've used for almost 30 years (which has apparently gone downhill since my buddy retired) inspected my TR3 radiator three different times, said it was "fine" and didn't need to be rodded out. After months and months of fighting a very persistent overheating problem (which included several return visits, removing the apron and so on), I finally asked that they rod it anyway. Surprise, surprise, every single tube was coated inside, to the point that the rods would not go through! They were only partially blocked, so the coolant still flowed through all the tubes, but the "mud" (as they called it) was obviously blocking heat transfer.

They did eventually manage to force the rods through, but opened up 5 or 6 leaks in the process, so I just had them recore the radiator. No more overheating! In fact, the only time my gauge has been above the '5' in '185' since then is when I deliberately disconnected the radiator fan as a test.

 

[mgedit]

Randy, pretty sure it is just corrosion related. System was "empty" when I filled it last Fall with single type of antifreeze.

Randall, will bear that in mind when I take the rad to the shop today. I'm inclined to go for a recore anyway as I believe this is the original 56 vintage rad.

Cheers, Mike

 

[TimK1955tr2]

Hi, I have a TR2 that had been sitting for decades and I got back on the road a few years ago. My block drain was completely sealed with sediment, I had to dig out the opening to get the coolant to drain. I filled the cooling system with Evaporust and let it sit overnight, I think I did this a few times, like once a year. During the summer, I would drain the anti-freeze and run water for a little while so I could do a few quick and easy drains back to back. I figured driving the car would start to shock the sediment in the bottom of the block, loosening it up due to vibration and heating/cooling.

Not sure if you have Evaporust in Canada but it is a very easy and pleasant product to work with.

Also, so garden hose pressure can burst a heater core? I don't have mine installed and haven't even looked it recently, is the core that delicate?

 

[sp53]

Yes the heater cores are old, fragile, and hard to come by. I would remove it and clean it out by hand over the sink with mild soap and hot water by filling it and shaking out the crap by turning it upside-down and maybe a piece of wirer to fish stuff out. They sit in the cars for year in a high point of the cooling system and catch grime. If you do pressure test it, make sure your have it clamped or it with open up like an accordion. Do not trust a shop to test it because they have probably not seen one before and will blow it up. Most those guys too busy and unexperienced to provide the care needed. I had a shop hand me back one years ago that grew an inch and when I complained looked at me like what is your problem I cleaned it out real good; it does not leak.

 

[TimK1955tr2]

Ok, great, thanks for the info!!

 

[TR3driver]

Also, so garden hose pressure can burst a heater core? I don't have mine installed and haven't even looked it recently, is the core that delicate?

Depends on where you live (how far downhill from the water tower); but 80 psi is pretty common for water pressure and some places are as high as 150. Of course it usually doesn't reach that while the water is flowing, but it will if you connect a hose directly to a blocked (or nearly blocked) heater core.
The TR2/3 heater core design is particularly weak, because it uses those wide, flat tubes.

 

[mgedit]

I was cleaning my old heater core out in the sink and thought I had it pretty clean so I decided to run water from hose through it just make sure I got it really clean. Not a good idea. Had very little flow but as other have said it did the accordian thing. I think the way to go is just to let gravity and time work their magic. Remember the cooling/heating system only works with 4 lbs rad cap. I am now very careful with my new heater core! Cheers, Mike

 

[mgedit]

Not sure if you have Evaporust in Canada but it is a very easy and pleasant product to work with.

Just did a quick Google search and Evapo-Rust is available in Canada. Thanks for the suggestion. Had not noticed it before. Cheers, Mike

 

[dave m]

hi mike
-after you get thru flushing your engine , think about using a product called "EVANS RADIATOR FLUID" INSTEAD of antifreeze/ water
-does not corrode , so you won't have the brown sludge every couple years
-install once , not every 4-5 yrs like a/f (fairly expensive but you only do it once)
-does not expand like water does , so no blown hoses etc
-does not boil in the water chambers causing hot spots and air pockets

-u tube has a couple good videos on it
-i have installed in all my cars tr3 , tr250, morgan

 

[GTP1960]

hi mike
-after you get thru flushing your engine , think about using a product called "EVANS RADIATOR FLUID" INSTEAD of antifreeze/ water
-does not corrode , so you won't have the brown sludge every couple years
-install once , not every 4-5 yrs like a/f (fairly expensive but you only do it once)
-does not expand like water does , so no blown hoses etc
-does not boil in the water chambers causing hot spots and air pockets

-u tube has a couple good videos on it
-i have installed in all my cars tr3 , tr250, morgan

Dave, i plan on switching to Evans, in my 60 TR3A , as part of my winter project.
only thing that concerns me is the necessity of completely removing all the old coolant, especially in the heater system.
in the youtubes I watched, the mechanic used high pressure forced air (through the hoses) to completely dry the systems.(must absolutely remove all the old coolant or Evans waterless is rendered ineffective)
i'm concerned about the effect on the heater core.

Do you have any pearls of wisdom here?

Best regards,

Guy Pierce

 

[GTP1960]

Yes the heater cores are old, fragile, and hard to come by. I would remove it and clean it out by hand over the sink with mild soap and hot water by filling it and shaking out the crap by turning it upside-down and maybe a piece of wirer to fish stuff out. They sit in the cars for year in a high point of the cooling system and catch grime. If you do pressure test it, make sure your have it clamped or it with open up like an accordion. Do not trust a shop to test it because they have probably not seen one before and will blow it up. Most those guys too busy and unexperienced to provide the care needed. I had a shop hand me back one years ago that grew an inch and when I complained looked at me like what is your problem I cleaned it out real good; it does not leak.

SP53, thank you for your suggestion to remove the heater core & clean it. That sounds like a good idea!

Question is: what is the best way to get to it? Do I need to remove the dash?

Best regards,

guy Pierce

 

[M_Pied_Lourd]

SP53, thank you for your suggestion to remove the heater core & clean it. That sounds like a good idea!

Question is: what is the best way to get to it? Do I need to remove the dash?

Best regards,

guy Pierce

Off the top of my head, to remove the heater , you don't need to remove the dash. There are three attachment points. One stud on the top of the heater that goes through the bulkhead into the engine bay and two bolts/nuts on the support bars/rails beside the heater where the heater bracket rests. You would need to undo the two heater hoses, the ducting connection on the side of the unit and disconnect the wiring to the switch and a ground wire.

I think that's it...

Now, I suppose you could just remove the core if you undid the coolant hoses at the top, pop off the clips that sandwich the top and bottom of the heater to the core, and drop everything down. I'm not sure if the fan gets in the way though....

I find it easier just to remove the whole unit then separate it if required...

Cheers
Tush

 

[sp53]

Unhook the battery first, there is a 3 legged bracket that holds the heater and there is one stud/nut that goes through cab and onto the firewall, and you might as well get that first. Next undo the choke cable and power wire for the heater and always bear in mind that the temp gauge tube is delicate and in the way. You can leave it hanging around, but keep a close eye on it and perhaps gently tie it off with play in the tie in case you accidently hook onto it so that it gives while you are working under the dash. I would say take the gauge out, but they are often stuck on the thermostat housing. Remove the heater dash brace under the glove box and pull the glove box out for better access. Leave the brace on the driver’s side in to hold the weight, but take out the screw in the center that holds the heater bracket and maybe loosen the bracket for wiggle room. The heater will know drop down some and you can pull the defrost hoses off. Either undo the heater hoses on the body tub where they pass through or just cut them and replace them later. It is just too difficult to undo them off the heater top. At this time the water will start coming out ,so get some that fits to catch it.

Once the heater is out getting the fan off is tricky. You need to hold the fan and turn the brass nut on the shaft through the small opening. The three spring brackets are also unnerving. You basically have to pry them off from the top and they want to fly, so wrap the heater around a towel or pop them off while the unit is in a trash bag or something.

 

[TR3driver]

Don't forget though, you need those stiff heater hoses. Common soft hose will kink above the core fittings and block flow through the heater.