| 15a V8 
cooling sequel
 Jerry Bright (Citron 1956) provides a sequel to 
Colin Leisk's comprehensive V8 Workshop Note 15. (Jun 79)
 
 I was interested 
in Colin Leisk's recent excellent article on the MGBGTV8 cooling system as I have 
experienced several of the problems he has dealt with. For my "family" 
transport I have a Rover 3500S and though there were differences between the V8 
engine in the MGBGTV8 and the Rover 3500S, the cooling system pressure is the 
same at 15psi. I had the Rover first and soon after I bought it, found there was 
a necessity for frequent topping up. As this was expensive I decided I wanted 
to get a tester to identify all the problems once and for all.
 
 I 
bought a Sykes-Pichavant Cap and Cooling System Tester (now about £25 plus 
VAT) and found it comes in a metal box about 6 inches square and 4 inches deep 
and will test two things:
 
 > 
The pressure the radiator cap 
will hold before blowing off.
 
 > 
That the cooling system can hold 
the pressure at which it is designed to run.
 
 The device is basically 
a pump with a built in pressure gauge. Testing the cap is achieved by screwing 
it to the mouth of the ester and pumping up in this case to 15psi. Any cap which 
will not reach 15psi before blowing off or will not hold 15psi for about 10 seconds 
is defective.
 
 In a similar way the cooling system can be tested by attaching 
the pump to the system with the connecting hose supplies with the kit and pumping 
up to 15psi. If all is well, the pressure will hold up. If this test is done when 
the engine is completely cold, the coolant will not evaporate as soon as it escapes 
and leaks are more easily spotted. The tester can be used to test nearly all British 
made vehicle radiator caps or cooling systems, and additional connecting hoses 
are available for those foreign makes!
 
 So what did I find from my tests 
using the cap and cooling system tester?
 | Back 
to Contents listingRover 
3500S 
 > Radiator 
cap defective, blowing off at 10psi.
 
 > Steam 
pipe connection to the inlet manifold defective though the clip was apparently 
tight. The problem was solved by fitting a clip with a smaller width and circumference 
before tightening up.
 
 MGBGTV8
 
 > Radiator 
cap defective, blowing off at 12psi. Solving this was rather more expensive 
here - two small leaks in the radiator tubes and also a leak where another tube 
joins the header tank.
 
 > Radiator leaks - I will probably opt 
for a completely new radiator core before I put the car back on the road in May. 
Patching up a radiator is at best only a temporary solution.
 
 Although 
the purchase of a system tester may seem a somewhat drastic step to take, I have 
convinced myself that it has been well worth the expense. It is always there for 
use next year and the year after . . . Also the consequences and likely expense 
of a seriously overheated engine can cost a great deal more than £30!!
 
 Now some notes on 
heater hoses for the MGBGTV8.
 
 
  
 | Description | Part 
No |   | Main 
hose top | GRH512 |   | Main 
hose bottom | GRH511 |   | Bypass 
hose | 90611532 |   | Hose 
heater to valve | BHH1083 |   | Hose 
heater to tube | BHH1082 |  Peter Beadle suggests 
a substitute part, AHA9782, for the hose from the heater to tube (BHH1082), 
which is a Spridget part.
 
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