Disco 2 No Brakes of almost no brakes.

I'm sorry but that's wrong. It used to be right, but the modern batteries you get off the shelf need a charge of ~14.7v for a full charge.
Most modern cars also only charge to ~80% for emissions purposes

kermit_rr said:

I'm sorry but that's wrong. It used to be right, but the modern batteries you get off the shelf need a charge of ~14.7v for a full charge.
Most modern cars also only charge to ~80% for emissions purposes

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Agreed. A charge voltage of 14.6 is perfectly normal.

That does not explain why I was able to start my vehicle, after sitting for six weeks, and drive it onto a transporter. When it returned from its chassis replacement, ten weeks later, it would not hold a charge. New battery £149... The Discovery 2 was designed in the late nighties and may or may not come into your 'modern' term. Surface to say that the replacement Alternator charges at 14:3V with both heated screens and both front heated seats switched on, for a load, at 2k rev. I am happy with my opinion but I respect that you may have a different opinion!

Nodge68 said:

Agreed. A charge voltage of 14.6 is perfectly normal.

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older cars designed around standard 'wet' lead/acid batteries would charge at 13.6v
modern VRLA/calcium enriched etc batteries are sealed for life and need a higher (14.7v) charge
start stop cars require AGM batteries which also have a different profile and why most battery chargers have a specific AGM button

you said the volts dropped to 9v on cranking, thats a sign of a weak battery thats no longer holding a good charge due to internal damage (sulphation) this happens as a normal process as batteries age (or left below 12.4v) and is why you had start problems

Stanleysteamer said:

Wouldn't his oil pressure light come on in those circs and could he still drive it 40 miles home?

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If it was a blockage to the vacuum pump then maybe not.

backinblack said:

If it was a blockage to the vacuum pump then maybe not.

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I meant if his oil pump bolt let go!!

Stanleysteamer said:

I meant if his oil pump bolt let go!!

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I didn't think it was down to his oil pump bolt, I was just saying that the vacuum pump needs oil or oil pressure.
We all know his is still fine cos he was able to drive for 40 miles.

backinblack said:

I didn't think it was down to his oil pump bolt, I was just saying that the vacuum pump needs oil or oil pressure.
We all know his is still fine cos he was able to drive for 40 miles.

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I get your point and I do fear the oil pump bolt on mine going.
If i had more time and space and a decent garage and I could empty the oil out of mine without having to pump it out, I'd have a look at mine!

Stanleysteamer said:

I get your point and I do fear the oil pump bolt on mine going.
If i had more time and space and a decent garage and I could empty the oil out of mine without having to pump it out, I'd have a look at mine!

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I was very lucky that mine went a few hundred yards from home but the 2 day strip and rebuild on the drive was a PITA

Stanleysteamer said:

I get your point and I do fear the oil pump bolt on mine going.
If i had more time and space and a decent garage and I could empty the oil out of mine without having to pump it out, I'd have a look at mine!

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Replace it with the upgraded pump?

kermit_rr said:

Replace it with the upgraded pump?

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I was thinking of the famous bolt that sits in the pulley accessed through the sump.

Removing the Alternator is fairly easy when you have cleared away all the structure around it, fan cover, fan and the cooling system bolted above the fan pulley, battery box etc. The bolt in the bottom of the Alternator is difficult to remove that is unless you remove the idler pulley. The big thing to remember is that the idler is a Left Hand thread! Then there is the Alternator bolt itself. This requires a Torx Bit and the other end is captive nut so with a bit of care, not to push the nut out of it's captivity,
removing or replacing this bolt is, compared to most things on a TD5, quite easy. Then you can pull it off the oil return pipe!

I am concerned that there appeared to be no oil in the air pump when I took off the alternator. (Typical Land Rover why sell two components, air pump and alternator, when you can charge the costumer for two components one of which may be perfectly all right). This will require some investigation to find out why. NB the sump oil is about 1 or 2mm above high, bit high but not enough to worry about.

With 'Kermit_rr' comments about 9V. If the battery is poorly charged or cannot hold a good charge then the starter motor may, may, pull the battery volts to less than 9V, a good battery will have more than 9V upon cranking and therefore satisfy the Engine ECU requirements. In 9V or less circumstances the engine ECU may fail to start the engine but it could allow the starter motor to run. Clearly in warm ambient temperature or a warm engine this is less of a problem.