Dear All,
Thanks to all of you who replied with such helpful suggestions regarding
my cooling system problem. I think Randall may have identified the
first cause:
>Since you say you've tested the thermostat, I wonder if the seal on the water
>pump is bad and allowing air to be sucked in when the engine is cool (and thus
>the coolant is not under pressure). I've never seen this on a Triumph, but I
>have on other cars and the symptoms are similar.
>
The seal on the water pump *was* bad - the orange rubbery stuff that I
found in the heater control valve came from a DPO's attempt to improve
the water pump seal in place of actually buying and fitting a gasket. If
it was circulating around the system, it certainly wasn't sealing the
water pump! This then caused a blockage in the heater control valve,
which meant that flow was restricted, that the heater failed to work,
and that the engine began to overheat.
I think that Steven Newell correctly diagnosed the subsequent problem:
>your radiator threw up but
...
> overflow bottle
>couldn't hold it all
...
> -- You topped it up but didn't purge all the air and within minutes
>the coolant was effectively low again. So it ran hot again, and when
>you removed the thermostat it increased coolant flow significantly so
>the car ran cool enough even with air trapped somewhere. You checked
>everything but still didn't purge all the air (hence still no heat),
...
>then you stabbed the radiator to cover your tracks
...
>there's still air trapped somewhere, and the tank has been critically
>wounded.
On several occasions yesterday, I noticed that all that came out when I
undid a hose clamp was hot air, but I stupidly failed to draw the
obvious conclusion that I had an air lock. I "burped" the system this
morning, and, even with coolant peeing out of the rad, the needle on the
temperature gauge never went over the 1/4 mark, and the heater was
providing lovely warm air in the cockpit again. I think I've solved
it. If I'm right, the root cause was the failure of the water pump
seal, leading to no less than three further separate problems in the
system (air locks, foreign matter blockages, burst rad [I've removed it,
and found that the hole is not accessible, so I can't have speared the
thing after all: it just gave up the ghost.]). I've cleaned off and
replaced the orange gunk with a proper gasket, removed as much of the
gunk as I can from the rest of the system, and will get the radiator
sorted when everyone comes back from their holidays. Either a radiator
repair, or a new/recon rad, and meticulous burping next time around, and
I should be OK.
Thanks again to all those people who replied, both on and off the list.
I couldn't possibly hope to run Triumphs without you guys!
A Happy New Year to one and all.
ATB
--
Mike
Ellie - 1963 White Herald 1200 Convertible GA125624 CV
Connie - 1968 Conifer Herald 1200 Saloon GA237511 DL
Carly - 1977 Inca Yellow Spitfire 1500 FH105671
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