Technique Matters

Butch adds coolant to an MGB

Butch shows how it’s done

A number of years ago a local boy bought a last of the line 1980 MGB which needed a cooling fan motor or two, which is a simple enough job. What was a bit more complicated for the owner was replacing the coolant that the car continued to lose.  Unlike the earlier cars, the 1977 on MGB’s lack a conventional radiator cap, routine replenishment is accomplished thru the expansion tank on the right hand side of the engine bay. like the MGC which appeared ten years previously.  Complete replacement of the coolant is effected thru a fill plug on top of the thermostat, and these originally were plastic and had a nasty tendency to break and shower the hapless attendent with a tsunami of hot coolant.  It’s been years since we’ve seen one of those, but we still keep a brass plug around just in case…


a melted oil filler cap

Bad Cap

This is a pretty lousy way to do it because not more than a trickle gets by the thermostat, and very slowly at that.  Our approach is to undo the top hose from the thermostat housing and pivot it 90 degrees up and fill thru the hose until the trickle is coming out of the ‘stat instead of trying to get in.  Well our friend decided to drive out to the shop so we could do it for him, and as I recall he showed up on foot about an hour late for his appointment, his car having expired on the grade out from Putney.

That car got some hot, as you might imagine, hot enough to melt the oil cap and that is in fact some of it on the rocker arm which was underneath it, too.


an MG TD engine about to come out

Engine out time

It’s been a week of MGB’s, four or five of ’em depending on how you’re counting, and it’s been exceptionally busy for this late in the year.  So for a change of pace we decided to take an hour or two and haul the engine out of the MG TD MkII which the owner trailered up from Massachusetts on Monday.  While we understand it got a little low on oil, we know it doesn’t turn, which is interesting because even after its epic meltdown, the 1980 MGB engine did.


Sunbeam Alpine

The Sunbeam Alpine on test Monday

Now about those Corrigans from last week, there were actually three:   from the top of last week’s post, a trailer loaded with the most of the weight behind the axle is going to have a tendency set up an oscillation that will whip the tow vehicle back and forth quite violently.

When this happens standing on brakes is the wrong thing to do, you need to stand on the accelerator pedal instead.  If you don’t quite grasp the concept, try repeating the exercise on a table with a piece of string.

The second Corrigan was also the third.  As pointed out in the story, the leading brake shoe in the second picture was the wrong way around, but I also identified the car as a 1963 MGB, which it can’t be, because it’s a tube type axle (you can identify that by the hub) and those didn’t start coming into serivce until the introduction of the MGB GT in 1965.

A footnote:  this is the 200th consecutive weekly edition of This Week at The Shop


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