T-Type Overheating: Part 1

11 Aug

Inspired by an article I received from Alan Atkins, I thought I would run a series of articles on this subject. Alan’s article was very useful but it was a bit of a “catch all” on overheating and I wanted to be more focused in separate articles, as well as wanting to catalogue my progress on TC0750. Nevertheless, his article has given me lots of good information and has served to assist me with a framework within which to work.

Alan made the point that overheating is not a new complaint with older vehicles, many of which did not have a thermostat to control the engine temperature and whose cooling systems ran on the thermo-syphon principle. Now, there is nothing intrinsically wrong with the thermo-syphon set up – it works perfectly on my PB – but the problem comes when one encounters a traffic jam and the temperature gauge climbs and climbs, giving one palpitations!

I can recall family days out in the late 1950s (yes, I can remember back that far, but can’t remember what I did yesterday!) to Weston-Super-Mare in the old Series 1 Morris 8 (EMU 419). Living on the south side of Bristol we came back on the A38 and had to climb the (then) notorious Redhill, south of Bristol Airport. Redhill wasn’t (and still isn’t) very steep, but it was a long upward pull, which ‘found out’ many an old car with a poorly maintained cooling system. In fact, it is no exaggeration to state that just over halfway up the hill and all the way to the top, the roadside was littered with old crocks with their bonnets up and clouds of steam pouring forth.

Looking back on this, I’m inclined to conclude that the cause of these boil-ups was, more often than not, the radiator. My conclusion was reinforced by experience a few years later when our 1952 Hillman Minx broke down with an overheating problem in Belgium. It seemed to take an eternity for the garage to remove the radiator and flush it through, but once done, the car ran fine and took us on through The Netherlands and into Germany.

Fast forward to 2011 and in between keeping a PB on the road and rebuilding a J2 I have been doing some work on TC0750. Having decided to get the engine rebuilt with a new steel crank and rods and a few other ‘bells and whistles’ I thought that it wouldn’t be a bad idea to remove the radiator and get it pressure tested and flow checked, which would be a start towards the engine rebuild (for which I am currently saving my pennies).

Now, as many of you who have worked on our cars know, jobs invariably turn out to be not as straightforward as one hoped. In my case, the removal of the radiator and shell and the subsequent separation of the shell to reveal the radiator and its surround in all its glory turned out to be a bit of a challenge – so much so that this article is more about the problems I faced rather than a contribution to the overheating debate.

The job started well and the bonnet (hood) tops and sides were removed quite easily. I removed the hinge from each bonnet side with the help of my IT man, who agreed to leave his computer for a short while. These were carefully stored (for heaven knows when they will go back!) and I was able to lift both bonnet tops off in one go with the centre hinge intact.

Next it was the turn of the radiator to bulkhead stay tubes to be removed and be suspended from the roof of shed number 3 using tie wraps (whatever did we do before they were invented?). At this point I ought to mention that the wings (fenders) had long been removed for repair, as had the headlights.

Having cut through all the hoses, which were well past their ‘sell by’ date and which will be replaced by a set of silicone hoses, it was just about time to have a go at taking the radiator and shell out as one unit. The two 3/8” BSF nuts securing the radiator to the support cross member were a little obstinate but gradually gave up the fight with the aid of some penetrating oil. As each nut was removed I was heartened to note that the flat washer which was positioned between it and the lower mounting rubber was exactly as per spec in the TC Factory Specification Book i.e. 3/8” x 1-1/4” x 0.72” Pl. washer (Rad. Securing Stud). No doubt some readers will think I am slightly mad but I like these little touches of originality!

Note: I’ve just remembered that there were two 3/8” BSF half nuts to undo, which were acting as lock nuts, before the BSF full nuts could be attacked.

So, the moment of truth had arrived, but nothing would budge. Experience over the years has taught me to be patient and not resort to ‘metallic torture’ as there is usually a reason why parts refuse to submit. In this case it was RUST; eventually, with some judicious wiggling and shaking it was possible to lift the radiator and surround out. The support cross member is very, very rusty and will need to be removed and be blasted and treated with POR 15 (by which I swear).

Next it was the turn of the radiator shell to be removed to get down to ‘brass tacks’ with the radiator itself. The radiator tape (total length 5’) needed to be threaded through the twenty four 1⁄2” drilled holes in the shell in order to gain access to the six (three each side) countersunk 3/16” BSF x 3/8” countersunk machine screws which hold the shell to the radiator casing (you could, I suppose call it the radiator sub-frame?). When these were released the radiator shell separated from the casing (sub-frame) quite easily.


Photo 1: The radiator tape being removed

A point to note about locating the 3/16” countersunk machine screws when reuniting the radiator shell with the casing is that the holes are elongated, which provides for some adjustment.

I was quite pleased with progress so far, but I had now reached the point where I would need some professional help. The radiator casing (sub-frame) was extremely rusty as can be seen by the following two pictures.


Photos 2 and 3: Two ‘shots’ of the rusty casing – worse was to come!

Clearly, I needed to remove the casing as I couldn’t leave it in the state it was. As will be noted from the pictures shown, it was only possible to undo one of the four 1⁄4” BSF x 1⁄2” set screws (two each side) at the bottom of the casing – the other three sheared.

I’ve gone a bit out of sequence here because the purpose of the aforementioned four set screws is to locate the bottom of the casing shown – having been removed – in the next picture.


Photo 4: Bottom of radiator casing showing ‘torture’ inflicted.

At this juncture I have to confess to the use of ‘metallic torture’ in that I hack sawed through what seemed to be a couple of layers of rusty metal between the inside of the bottom of the casing and the bottom of the radiator itself. In fact, steel strips on the bottom of the casing are soldered to steel strips on the bottom of the radiator to locate it in place.

Having removed the bottom of the casing, there was still a need to unsolder it at each side of the top of the radiator and underneath the header tank.


Photos 5 and 6: Two views of where the casing is soldered to the top of the header tank – it is also soldered underneath.

I had previously experienced good service from Raysons Radiators in Yeovil, but as they are situated 40 miles away and I wanted the casing to be unsoldered for me to arrange repair before taking it back with the radiator to be pressure tested and flow checked this was not an attractive option. I then recalled that fellow TC owner, David Lewis had received excellent service from a company called Advanced Autocooling (Bristol) Ltd (www.advancedautocooling.co.uk). As luck would have it they are actually situated on my doorstep (within two miles).

They couldn’t have been more obliging and un-sweated the casing from the radiator while I waited! The picture below shows the two side pieces of the casing after un-sweating from the radiator.


Photo 7: The two side pieces of the radiator casing after they had been un-sweated from the radiator.

Three of the captive nuts had also rusted out and needed to be repaired. Fortunately, a PA and PB owner (Fred Wheeler), who lives about 12 miles south of me not only brazed in new captive nuts, but also grit blasted the two side pieces of the casing. I immediately applied some POR 15 to the bare metal pieces.


Photo 8: A bit of a sorry sight with captive nuts no longer captive!

Fred also repaired the bottom of the radiator casing for me so that it was all ready for Advanced Autocooling to solder it on to the bottom of the radiator, along with the two side pieces that I had painted.

All was now ready to take the radiator and the restored casing to Adavanced Autocooling but before doing so I ‘dry assembled the casing to the radiator to check everything fitted.


Photo 9: The restored and painted side casing pieces (compare this with photos 7 and 8!)

Photo 10: The restored and painted bottom casing (compare this with photo 4!)

Photo 11: The tested radiator – still to be painted

Advanced Autocooling repaired four small leaks in the radiator and did a flow test (good flow reported) for £60. It’s good to have reliable professionals on one’s doorstep and capable M.G. friends like Fred Wheeler.

JOHN JAMES (TC0750)

Overheating Part 2 in next issue.


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One Response to “T-Type Overheating: Part 1”

  1. Benny Grumer 10. Nov, 2012 at 9:42 am #

    Hi Mg Tc lovers
    Can anybody tell me what is used as a padding between the radiator and the radiator lower frame, is it rubber foam? solid rubber matt? what is the thickness of the matt.
    Thanks
    Benny

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