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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Coolant Recovery Bottle

As I said in another thread, I am getting ready to mount a coolant recovery tank in the TD. The statement on O'Connor's Classic's web site is a bit confusing. I certainly understand NOT using a pressurized cap on the recovery bottle, as our system is not pressurized, but what do they mean by, "... use the normal cap for your car, and make sure it's in good condition.

Yes, I use the normal cap on my radiator, but what cap goes on the bottle? I have seen pressure caps, with the sealing lever "up" so they are not pressurized used, but is that the only option?
L Karpman

Larry - "DO NOT use the pressure cap which usually comes with the coolant recovery system; use the normal cap for your car, and make sure it's in good condition" I added the the emphasis. They are saying NOT to use the pressure cap for the T series cars, but to use the regular cap and make sure it is in good condition. To me that means to make sure it seals properly (for those with TFs, the pressure cap supplied with a coolant recovery kit would be too high a pressure for the TF, just use the standard pressure cap and insure that the secondary seal works properly and tha tit has a check valve in it as all pressure caps made today have). If the standard cap doesn't seal properly, no vacuum will form when the cooling system cools off after shutting the car down and will not pull the coolant back into the radiator. The referance to adding a coolant recovery system wit the later MGBs with a seperate expansion tank is incorrect, the expansion tanks serves the same purpose as the coolant recovery system.

I also take exception to the statement in the article on the fan that adding the plastic fan reduced the system temperature by x number of degrees, even when traveling at 65 MPH. I would be willing to bet that they did other work on the car at the same time thay added the fan (like cleaning the radiator, cleaning the cooling passages of the block and head, opening the slats of the grill and perhaps adjusting the timing, etc. Ther is just no way any fan is going to pull enough air to make a difference in the cooling at 65 MPH. Cheers - Dave
David DuBois

I have no intention of using the cap that came with the recovery bottle. Guess I'm having trouble explaining my question Dave. I have the standard TD radiator cap on the radiator (nose). My question is, what type of cap should I put on the recovery bottle?
L Karpman

Larry, see http://www.ttalk.info/Tech/Overflow_tank.html. I use one of the levered caps, but with the lever up so as to bu unpressurized.
Bud Krueger

Yes, I saw that a while back Bud, but I was looking for an alternative, but my brain won't engage today :-)
L Karpman

I installed a coolant recovery bottle on my Model T and Model A Fords. Have not got one for the TD yet. I purchased the recovery tank kit from the local AutoZone. It does not have a pressurized cap, just a snap on lid. The gasket on the radiator cap needs to be in good condition so that it will seal the filler neck. There is no pressure, as the overflow tube is below the gasket and cap. A plastic tube connects the overflow to the recovery tank. The radiator stays full to the top. Any excess coolant from expansion goes into the tank and is sucked back as the engine cools. Simple system and saves dumping expensive antifreeze on the street. I have not seen an accessory recovery tank with a pressurized cap.
John Masters

Thanks John. I have no intention of putting a pressurized cap on the recovery bottle. Bud has one with a lever, and keeps the lever up to ensure no pressurization, I would prefer an alternative, as I'd probably accidently, one day, push the lever down :-).
L Karpman

Larry - Do you already have a recovery bottle that has a pressurized cap with it? If not, then when you purchase the bottle get one that doesn't have a pressure cap. If you have a bottel that has a pressure cap that goes on it, just drill a 1/4" vent hole in the neck of the bottle just under the cap and it will work fine even if you don't leave the lever up - in fact, with the vent hole, there will be no need to leave the lever up. Cheers - Dave
David DuBois

I already have a midget bottle, with a pressurized cap. I have discarded the pressurized cap, and will buy a non pressurized cap. Wouldn't drilling the hole prevent the coolant from being sucked back to the radiator on cool down?
L Karpman

I think my brain awoke and I answered my own question. The hole won't affect suction as the coolant hose is submerged all the time.
L Karpman

The overflow recovery bottle seems like a great idea in that it keeps the radiator full to the top and helps cooling but where do you install the container?
Alan

Most seem to put it by the battery. You need it elevated. I will be putting mine in the same spot that Bud Kruger shows in the picture.

http://www.ttalk.info/Tech/Overflow_tank.html

Larry
L Karpman

Where does the other tube enter the rad?
gblawson - TD#27667

The tubing connects to the outlet of the overflow pipe, i.e., below the radiator.
Bud Krueger

Both tubes?
gblawson - TD#27667

The 70 B I sometimes care for has a coolent recovery bottle I installed. Of course, the B is pressurised and it has a drain tube that runs from the filler neck to the ground.

I took a wipes container with a sturdy pull off lid, you know, the kind with the hole in the center to pull the out the wipes? I shortened the hose slightly and chamfered the bottom cut. The container is located below the fill neck, and we did get a new pressure cap with a secondary seal for the fill neck, i.e. a seal for the radiator header and a second seal for the rim of the fill. To my surprise, the bottle functions in both directions, accepting overflow, and then sending it back on cooling. I would have thought that the radiator would not have had enough suction to return the coolent, but evidently, it does.

http://i44.photobucket.com/albums/f33/dave4419/recoverybottleinstalled2.jpg

warmly,
dave
Dave Braun

"Both tubes?"

Gordon: I assumed the tube from the neck of the overflow bottle went to ground. Is this correct Bud?

Larry
L Karpman

Looking at Dave's (damn...another two hours going through his photos) it makes sense...water goes into the bottle and gets sucked back? Of course that is on his B and is pressurized... Can the single tube from the TD's overflow go into a bottle like that ?
gblawson - TD#27667

Sheesh Gordon! That was a single photo from my photo hosting service, not the photosite I use for keeping track of my TD restoration! If you spent two hours looking at that one photo....

The part of the 'sucking back' that I have a problem with is that once the overpressurization is over, and the pressure cap closes on the B, how does the overflow reenter the header on the radiator? Somehow, it seems to me that a vacuum would be hard on the radiator itself. Also, in therory, it seems that at some point the over flow should result in a level in the radiator that would no longer be susceptible to overflow, unless boiling occured. In a properly maintained system we should be able to eliminate boiling.

On the B, it was driven hard a couple of weekends ago, the fluid expanded into the overflow bottle, nearly filling it, and the next morning was observed to be back to its 1/4 full level. I just don't see how it does it...

On a TD I think that the overflow would have issues with the bottle being higher than the header tank of the radiator, and that the low sweep the drain tube makes to go from the road level drain point up to the bottle would be prone to air entrapment. I guess, like the B, the only way to know for sure is to try it.

warmly,
dave
Dave Braun

I have found (even though I am following this thread with interest) that if I overfill my rad, it will spill out the overflow when warm...but it reaches a level that doesn't let any more escape...and seems to stay level (just about 1/2" above the core! Don't think I've touched it since spring!
gblawson - TD#27667

Gordon, before ionstalling the overflow tank I was using a motometer to monitor my water temperature. About the time that I discovered that my overflow coolant was causing the mess on my bonnet and fenders I realized that the loss of the top inch, or so, of coolant was keeping the liquid away from the mercury bulb of the motometer. The overlow tank system solved both issues, the mess and the coolant level. I've since added a dual-guage with a temperature reading and sold off the motometer. Since adding the overflow system I've never had to add coolant, nor have I had it mess up the paint.

The MGB bottle has two tubes. The input one comrs from the bottom of the radiator overflow pipe and goes down to the bottom of the MGB tank. The other tube is an overflow tube from the overflow bottle and goes down the side of the engine. Does this work to receive coolant from the radiator and then return it later? Beats the daylights out of me, but I've never had to add any.
Bud Krueger

Ok now that all the sucking and dripping questions have been answered , may I ask if there is any noticeable improvement in cooling ability to warrant having that colosimy bag hanging on my battery.
By the way good photo . I like the blue wire markers on the fuse block , I thought I was the only one with them . Only mine are made of duct-tape and felt tip marker numbers. I am a Gypsy at heart.
Alan

Alan,
I installed a coolant recovery bottle on my TD (drilled a hole in the cap so as not to have it pressurized) and drove all summer and never added any coolant...many days in Idaho over 95 degrees and frequent trips over 5000' passes....last year without the coolant recovery tank I had to top up the radiator almost daily.
Robert Dougherty

Gordon - The radiator cap on a MGB (or any modern car) has a check valve in it to allow the vacuum formed in a colling radiator to be released, either by drawing air (if there is no coolant recovery system) or the expelled coolant in the reservior of a coolant recovery system. The second tube entering the coolant reservior is a overflow/vent tube. If the cooling system should become overheated to the point of boiling, it is capable of pushing all the coolant out into the recovery system reservior, causing it to overflow.

While it is not necessary to fill the radiator in a TD clear to the top (unless they are using a motometer), the coolant will establish its own level, which is down as much as two inches. It will stay at this level for quite a long time. My problem with this level is that I felt it was very close to the level of the temperature sending bulb in the header tank. If (when) the coolant drops a bit further, the bulb is no long in the coolant and therefore the gauge will not indicate the true temperature. With a coolant recovery system, the coolant level remains even with the top of the overflow tube.

I made my own coolant recover system out of two inch plastic pipe and it resides next to the 26 series battery in the battery box. Anyone wanting to see pictures, just e-mail me. Cheers - Dave
David DuBois

Robert Dougherty,
Thanks for the reply. I may try to build one and try to make it as invisible as possible.
Ah Idaho, are you East or west . I adoped some wolves in Western Idaho in the Sawtooth Mtns. God is that a fantastic area . You would find it hard to belive it is in this country. My wife says it is "senic over-kill".
Alan

Since pressurized cooling systems are a bad thing, i am running out to my present day cars, to remove the cap!!
Len Fanelli

I've got everything installed, and just need to connect the radiator overflow hose to the hose to the coolant recovery bottle. The hose for the coolant bottle is already routed under the left side and waiting to be connected. Anyone have a "suggested routing" of the drain hose from the right lower side of the car to the left so I can connect and avoid any pitfalls?

Thanks

Larry
L Karpman

Larry,
Since I installed a heater and the hoses run along the top of the engine, I ran it up the right side of the front then over the top attached to the heater pipes...you could use the same routing without heater pipes. Like others, I was able to find an MGB overflow tank on Ebay so at least I can say it's a purely MG addition!! I'll email you the pictures.
Alan,
I'm in Boise but get up into the mountains fresquently...just caught a 16" 3Lb rainbow yesterday!!
Robert Dougherty

Thanks Bob. I have a Midget tank. Same one I believe. I routed mine today down the left side of the engine bay, outboard of the steering shaft, then along the rear of the front crossmember to the radiator overflow pipe. Thanks again for the pics!!

As for the trout, lucky guy. I still have very faint memories of my 11 years living in Alaska :-)

Larry
L Karpman

I really can't understand why anybody would want to install a coolant recovery bottle. Just leave enough empty space in the radiator top tank to allow for the coolant to expand. If you are doing that and still losing coolant, then you have other problems.
Regards, Richard.
R Payne

Hi Len.
The higher the pressure the lower the boiling point .
Removing the cap from a normal car will cause it to overheat.
MG TDs are built with almost flintstone design and some how manage to get away with it to a " degree" sorry about that.


Robert D.
Stop it ,what are you trying to do make me feel bad?
Ha Ha
We bought a motorhome and would like to head out that way again if gas prices come down a tad. 8 MPG on flat high way ouch.
Alan

For the originality police, i agree with Richard. For drivers, why bother with a tank? Pressurize the system! It takes less space, is almost invisible, & helps prevent blown head gaskets, burned valves, & warped cylinder heads! As well As increasing the boiling point of the coolant.Coolant tends to boil at the exhaust valve area of the cylinder head.This creates a steam pocket around the exhaust valve. When this happens liquid coolant is not avalible.Presurizing the system helps prevent this from happening. A pressurized system results in less burnt valves, blown head gaskets, warped cylinder heads, & a more thermal efficent engine.A pressurized cooling system has led to higher power output, due to less loss of heat & horsepower through the cooling system.
Len Fanelli

Len, all you say is true, but I question two areas in this dicussion.

1. If a recovery or overflow tank is unnecessary in a pressurized system, why did manufacturers add them to pressurized systems?

2. Although the TD cooling system should be stout enough to handle pressurization, can that be assured with any certainty, as it was not designed with the components of a pressurized system?

Cheers

Larry
L Karpman

I have seen one radiator failure in a pressurized TD system. The large top tank area flexes with each pressurizing cycle. This results in either an eventual fatigue crack or splitting the weakest soldered seam. On the TF, they changed the top tank to eliminate the flexing. The water pumps are interchangeable.
Jim Merz

Len - Do you have any instructions for converting to a pressurized system? Dave
David DuBois

Dear all - I just read through this thread with interest and just wanted to ask why an overflow is needed on the TD?

We have driven a TD tens of thousands of miles over a 30 year period and have never had overheating - spitting problems -

I would think if the car is spitting coolant - then the system might have other problems. Always check the rad grill slats first - can you see the radiator inside through the slats? If not - then the slats are too restrictive and may be aftermarket. Has the interior of the block been cleaned of all debris? That stuff looks like cast iron when it fuses to the cylinder walls and blocks the drain holes in the passages.

I dont mean to be critical of LK's desire to put on an overflow - I just dont understand the need. I do think it is nice to keep the cars as close as possible to the contemporary configuration when possible.

Good luck with the modification - I just hope there is not a problem somewhere else that might be masked by the use of the overflow bottle.

best regards,

Jeff
J Delk

Interesting read Jeff, and good advice on the slats. I am new to the forum, and based my decision on adding the overflow bottle to the literally dozens of posts from long time T Series owners reporting "topping up" frequently when hard running or in hot climates, and many experienced T owners who have already added the bottle. I didn't do it based on my own experiences, rather the experience of other T Series owners with decades of experience with their cars.

I don't think the overflow bottle is there to mask any problem, but rather to catch any overflow in beastly hot running conditions. In the summer N. Texas heat we have most days over 100+ F, and when combined with a 53 year old system, radiant heat from other cars and pavement, and stop and go traffic, it is unquestionable to lose some fluid at times. The tank "should" simply catch the coolant and return it to the system, rather than having to manually top up when cool.

I'll leave the determination to those like yourself, far, far more experienced with the T Series than I, as to wheter it's a good addition or not. So far there are those on both sides of the discussion :-)

Cheers

Larry

L Karpman

Larry

I imagine Texas can really boil you - I cant imagine how hot it gets out there. Good luck with it and I hope it works for you and you are able to stay "cool."

Jeff
J Delk

Thanks Jeff, I'll try to stay cool, but I doubt it's possible here. Here it is October, and we are going up to the high 80's F again tomoorow :-(( So much for our "cold front" I lived in GA for 6 years in Coulmbus and then Savannah. I did own a TC at the time and can't recall a overheating issue, but that was 30+ years ago. Only time will tell whether this addition was worth the minimal ($15) expense to put in.
L Karpman

This thread was discussed between 09/10/2006 and 16/10/2006

MG TD TF 1500 index

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