Checking Big Radiator Hoses
by Lorne Goldman

The radiator is one of the most important components of your Morgan. It keeps the engine at its nominal operating temperature, typically between 90 and 105 degrees Celsius. Radiator hoses circulate coolant from the radiator to parts of the engine that need to stay cool. Over time, radiator hoses, especially Morgan Factory stock hoses, can weaken, harden or crack. If they are not replaced when necessary, they can completely collapse or split, causing the engine to overheat and be unable to run. If you do not happen to coincidently glance at your coolant temperature gauge, in extreme cases, a collapsed hose can cause the engine to crack. This article covers how to check radiator hoses and clamps.. 

GoMoG WATCHPOINTS: Morgans have more problems with these big rad hoses than most cars.
WATCHPOINT: A sad example of what this can mean was experienced when I bought a Melvyn Rutter +8 R&P lower rad hose.
It was not  a MMC hose, sold by Melvyn only. It pliability made it very easy to install (unlike the toughly reinforced MMC version).
But it soon split like  a ripe banana  and emptied my Morgan of coolant in a couple of seconds. Happily I did not lose control of
the car with coolant coated tyres  and I stopped soon enough to save the engine. I have since found that ALL coolant hose
problems with Morgans can be resolved with  higher quality hoses (which last forever!) or smarter fittings. For example, the
Mulberry method and design of the rad fittings makes  installation a breeze and mitigates the damaging pressure of the hoses..

1. These big hoses are not as pliable as smaller hoses and can exert great damaging force at their rad attachment points. Mulberry avoids passing on such problems to owners with a simple imgenuous design for his rad hose fitting. 

2. In the past, the classic rads were bespoke Morgan and did not change much over the years. However, the engines changed. The switch to R&P steering also altered the passage. As the passage changed so did the shape these hoses to compensate. (cheaper to change a hose shape than an engine or rad!). The hoses became pretty tortuous and exerted a lot of force on their fitting and themselves with the constant flexing of the chassis.


3. Over time, if the datum does not change, most design faults can be resolved. This was the story with Morgan up to 2000 or so. However, the constant changes since have made design fault detection more problematic as the cars are a constantly moving targets. Here is one example from the cooling point of view at the right.

4. The use of plastic rads have caused the current plague of rad failures. Morgans constantly flex. Though plastic rads are MUCH less costly, plastic is very brittle where metal rads has greater resistance to flexing. The solution is to find an earlier rad or fit your car with a bespoke alloy rad.
Checking Procedure

A. Find both of your radiator hoses. One reason radiator hoses are overlooked during a routine car inspection is that the hoses can be difficult to reach. 
  • The upper radiator hose runs from the radiator to the motor. You can usually see most of this hose.
  • The lower radiator hose is harder to find. To locate it, get underneath the car and look for a hose leading from the rad to the front of the engine.
B. Visually inspect each radiator hose. Hoses should not be swollen or cracked, both of which could lead to a failure.  

C. Perform a squeeze test. While the engine is warm after a drive, squeeze the radiator hoses, paying particular attention to areas where the hose bends
  • A radiator hose in good condition should feel firm, but not hard.
D. Check the clamps that connect the hose to the radiator and the engine.
  •  There are 3 different types of radiator hose connections, gear clamps, banded clamps and wire clamps. Gear clamps, which are sometimes called worm clamps, and banded clamps, which are also called screw clamps, are typically made of stainless steel and wrap around the hose. You adjust these types of clamps with a screwdriver. Replace Morgan clamps with stainless.  Wire clamps are adjusted with a pair of hose clamp pliers. You can recognize these clamps because there is no screw keeping them tight. 
  • WATCHPOINT Clamps are very inexpensive. Considering how important they are, buy the best. Check whether the clamping function has been destroyed by loosening and tightening factory clamps and term9ning whether they are, in fact, tightening any more. 
  • Hoses installed on a new, regularly used car tend to last about 10 years or 100,000 miles (160,000 km), whichever comes first. But it is a good idea to do radiator hose inspection long before you reach these milestones. 
  • Hoses installed on a car that is irregularly used last much less. Without regular coolant circulation, the hoses dry quickly and crack. After twenty years at this, I have arrived at the point where I simply tell buyers of low mileage Morgans to change ALL hoses on arrival.

P.S. While you are at this. Take a moment to check your hose (s) between the fuel tank filler to the fuel tank. These hoses suffer from the same problems as the big rad hoses and will not last as long as they are not being constantly lubricated.