Hi,
Please could anyone advise on whether a small amount of discharge from the rad overflow pipe is normal ?
Up to 1/4 pint seems to seep out and vent onto the garage floor overnight after the engine is switched off and the car cools down, on a modern car this would obviously pass into an expansion tank.
Not really worried about this as there are no leaks when hot / running and temp sits at 70 or moves just over when in traffic queue.
Cap is a stamped 7 and its the shallow rad filler neck (20mil) and correct size cap. When I screw the cap onto the rad the spring doesn't seem to offer too much resistance so wondered if the caps worth replacing for a new one??
Any observations would be appreciated.....................
Radiator Overflow............
Moderators:Aceman, ecosselynx
I too have a 340 which exhibits the same 'quirk'.
I think that the problem is that when topping-up the water, you should stop when the water barely covers the radiator top. The temptation is to go too far and as you realise, there's no room for expansion!
Off topic, but hey. My brother Colin and I have done some work on dipsticks, which in our opinion are the wrong length on many XK engines.
Again, the temptation is to add just a bit too much oil, which does no favours.
If you check the capacity specs and put in the amount of oil suggested, it barely registers on the dipstick! So, all the excess gets whooshed up and burnt.
I think that the problem is that when topping-up the water, you should stop when the water barely covers the radiator top. The temptation is to go too far and as you realise, there's no room for expansion!
Off topic, but hey. My brother Colin and I have done some work on dipsticks, which in our opinion are the wrong length on many XK engines.
Again, the temptation is to add just a bit too much oil, which does no favours.
If you check the capacity specs and put in the amount of oil suggested, it barely registers on the dipstick! So, all the excess gets whooshed up and burnt.
Thanks for the advice,
I tend to fill up to the bottom of the neck rather than just covering the cooling fin tops.
I guessed that if the cap was not 100 % then water would seap past the seal and out the overflow, with a proper seat I wouldn't really expect water to escape via the overflow, or have I got this wrong !!
I tend to fill up to the bottom of the neck rather than just covering the cooling fin tops.
I guessed that if the cap was not 100 % then water would seap past the seal and out the overflow, with a proper seat I wouldn't really expect water to escape via the overflow, or have I got this wrong !!
Hi there,
My solution has been to fit a small overflow tank (from a 60s MGB)on the inner bulkhead and pipe it from the rad overflow, fit a pressure cap to the overflow tank and a drain below the sub frame to ground, The rad then burps of overflow tank and when cold sucks back whats needed and maintains the level, not had a prob since fitting.
One issue with the original was that the overflow pipe drained onto the crows feet and did not disperse (adding to the corosion issue in that area!)
Ian
My solution has been to fit a small overflow tank (from a 60s MGB)on the inner bulkhead and pipe it from the rad overflow, fit a pressure cap to the overflow tank and a drain below the sub frame to ground, The rad then burps of overflow tank and when cold sucks back whats needed and maintains the level, not had a prob since fitting.
One issue with the original was that the overflow pipe drained onto the crows feet and did not disperse (adding to the corosion issue in that area!)
Ian
Thanks Ian,
So you've basically upgraded the system to an expansion tank set up, similar to modern vehicles.
Sounds like a good idea.
So the expansion tank you've fitted has a pressure cap (7psi?) and feeds from the rad overflow tube. Have you then got an overflow from the expansion tank neck feeding down the inner wing, just in case the expansion tank overflows / blows under pressure ?
So you've basically upgraded the system to an expansion tank set up, similar to modern vehicles.
Sounds like a good idea.
So the expansion tank you've fitted has a pressure cap (7psi?) and feeds from the rad overflow tube. Have you then got an overflow from the expansion tank neck feeding down the inner wing, just in case the expansion tank overflows / blows under pressure ?
Cooling
David,
Since we last spoke on this , my rad failed big time. Bit the bullet and bought a radtek ally race rad, bigger core and a piece of alluminium excellence that has to be seen to be appreciated.
Its stunning, fitted now for over 1000 miles, the Kenlow only cycles in on prolonged stops at junctions etc and I have not lost an ounce of coolant, put kevlar hoses on at the same time and very pleased with the result.
Bit pricy biut only £75 more than a "new" standard replacement.
Enjoy.....
Since we last spoke on this , my rad failed big time. Bit the bullet and bought a radtek ally race rad, bigger core and a piece of alluminium excellence that has to be seen to be appreciated.
Its stunning, fitted now for over 1000 miles, the Kenlow only cycles in on prolonged stops at junctions etc and I have not lost an ounce of coolant, put kevlar hoses on at the same time and very pleased with the result.
Bit pricy biut only £75 more than a "new" standard replacement.
Enjoy.....
Re: Radiator Overflow............
Over-filled rad is the culprit - mine does exactly the same.
I took my car to Bournemouth 'Classics on the Prom' a few weeks ago, just after the car had been serviced and rad topped-up - parked on a slight slope and had to leave after half an hour due to every passer by telling me my car had a leak - due to the rad dripping onto the ground!
Definitely only needs to be filled until the water is just visible in the filler opening, not higher.I thought about fitting a litle 'expansion bottle' to catch any overflow - some made for motorbikes look quite suitable (see link)
http://www.ebay.co.uk/itm/HONDA-HRC-RS- ... 4d02fc7ed3
I took my car to Bournemouth 'Classics on the Prom' a few weeks ago, just after the car had been serviced and rad topped-up - parked on a slight slope and had to leave after half an hour due to every passer by telling me my car had a leak - due to the rad dripping onto the ground!
Definitely only needs to be filled until the water is just visible in the filler opening, not higher.I thought about fitting a litle 'expansion bottle' to catch any overflow - some made for motorbikes look quite suitable (see link)
http://www.ebay.co.uk/itm/HONDA-HRC-RS- ... 4d02fc7ed3
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