~ Finally a warm sunny weekend. Drove the 66 MGB a bit yesterday. Walked
~ outside this morning to find a big puddle of anti-freeze under the car.
~ Further examination revealed that the drip was coming from a point on the
~ front of the engine block directly behind the radiator fan. This seems odd
~ to me, as I would have suspected the water pump. Any ideas as to what the
~ cause / fix is?
Well, since the water pump is directly behind the radiator fan on an
MGB, I'd say you've found your problem. :-) Seriously, on the B, the
fan bolts to a flange on the front of the water pump; the pump shaft
is concentric with the fan. You might also have a leak in the lower
hose that's causing a trickle that you can't see, as some of the lower
part of that hose is obscured by the front motor mount and the forward
edge of the block.
If you mean the leak was coming from the *pulley* behind the fan, rather
than from the block, this means the water pump has failed in the shaft
rather than in the gasket that holds it to the block.
You may also have a leak from the thermostat housing, which is on the
head at the front of the engine, or from the cylinder head itself.
Basically, you can either poke around more and find out what's really
leaking (looking in a manual or parts catalog to identify the actual
parts if you're not familiar with them), or you can start replacing
things beginning with the cheapest and easiest and getting more
expensive and difficult as time progresses. In that case, the first
step would be to replace the thermostat housing and its gasket, while
also cleaning up the fitting between the upper hose and the housing.
Then replace the water pump; it's easier, believe it or not, to pull
the radiator (that's six bolts in the shroud and it moves forward),
so that you have access to the fan bolts and then to the water pump
itself. The most time-consuming task would be swapping the head
gasket; that's also one that's more easily done with two people
as you have to pull the head up while bent over the fender, and if
you have another set of hands you run less risk of pulling a muscle
in your back when you lift.
~ As a additional bit of background, the engine was rebuilt 1500 miles ago and
~ at theat time the radiator was also overhauled, so I don't think there
~ should be any issue with coolant flow.
You may be lucky. Try to get a wrench on all the appropriate bolts and
a screwdriver on all the hose clamps, and just snug everything up (see
the previous postings on "mechanic's feel"). It could be that the motor
has just worked a little loose as it broke in. Did you torque the
cylinder head at 500 or 1000 miles?
~ On a different note, I tried to remove the radiator cap and found it
~ stuck.It's a pressurized cap. I'm assuming it should be removed by pushing
~ down and turning counter-clockwise. It's stuck and I'm stuck, since I don't
~ know if there is even enough anti-freeze in the radiator now to drive.
It's just an early form of child-proof cap. Turn CCW about 90 degrees,
*then* push down and turn some more.
Where are you, Jerry? It sounds like you need a course in Running and
Maintaining the MGB 101. If you're in the San Francisco Bay Area, write
back to me and I'll take you on a short guided tour of the care and
feeding of the BMC B Series engine and its ancillaries. For example,
can you locate the dashpots, the valve lash adjusters, and the lubrication
points on the distributor? If you answered "no" to one or more of those
questions, you're at risk of becoming a Previous Owner...
--Scott "Build on Saturday, install on Sunday, drive on Monday" Fisher
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