BJ8 Mystery water leak

[AndrewMawson]

OK I probably asked for this by back flushing and purging my BJ8 water system the other day, but I have a small water drip from the front of the engine. Hoses and their joints are sound, and the water pump seems ok, but logically it can only be from the water pump. The drip is about in line with the crankshaft and seems to come from that level but surely it must be coming from above. Stopping the engine so I can feel around everything apears dry - very odd.

Is it possible to pull the water pump with the radiator in place or am I in for removing the rad.

 

[gonzo]

You need to remove the rad before removing the water pump. I'm curious about the back-flushing and purging. Does this process require pressurization of the system? And if so how much pressure?

Healey systems operate at pretty low pressures, 7 lbs I think. Higher pressures in the system could cause some interesting things to happen, like blown gaskets or seals.

Try this simple test: With engine off, rock the fan blade - there shouldn't be any play, but look for the mystery leak around the seal or weep hole at the bottem of the pump.



Good Luck. GONZO

 

[AndrewMawson]

[ QUOTE ]
You need to remove the rad before removing the water pump. I'm curious about the back-flushing and purging. Does this process require pressurization of the system? And if so how much pressure?

Healey systems operate at pretty low pressures, 7 lbs I think. Higher pressures in the system could cause some interesting things to happen, like blown gaskets or seals.

Try this simple test: With engine off, rock the fan blade - there shouldn't be any play, but look for the mystery leak around the seal or weep hole at the bottem of the pump.



Good Luck. GONZO

[/ QUOTE ]


Gonzo,

The back flushing is done with an ordinary garden hose at low pressure running water in the opposite direction to normal flow until clean water comes out, and with the other end open, so I doubt if the pressure reaches anything like the normal operating 7 lbs. Purging is done by refilling the system and running for half an hour with a radiator flushing compound that dislodges rust particles, and hard water scale, and then back flushing again. Its amazing what is shifts! It was probably this that dislodged a "friendly" bit of build up that was sealing the gasket face of my water pump. Having checked the bolts were tight I put some patent radiator leak cure in the system and the problem was solved for now, though a new pump and gasket are on order 'just in case' /ubbthreads/images/graemlins/england.gif

 

[Dave Russell]

Back flushing a block can actually cause more harm than good. If the rust is just loosened & not completely carried out, it will be redeposited in the top of the radiator tubes when the engine is run, & plug the radiator.

Back flushing a radiator can remove some of the accumulated clogging of the tube tops. To be successful, this type of flushing requires a very large volume of water (high flow rate). Commercial shops use a combination of compressed air & water injected in bursts to increase the flow to effective rates. A garden hose will do little more than slightly stir things. Certainly better than nothing.
D

 

[AndrewMawson]

OK my concience got the better of me and today I whipped the radiator out, popped in a new pump and thermostat whilst I was at it, and am now waiting for the rain to stop to see if all is well.

Isn't it fun undoing those two rad bolts by the steering box, and the bottom hose clip. I reckon that they had a special breed of long fingered assembler in the factory, and the designer never dared go near a service bay !

Still - 3 1/2 hours end to end wasn't too bad.

Absolutely no sign of play in the old pump and the leak wasn't the gasket but the spindle seal.