Disco 2 Alternator Vacuum Pump Oil Leak

2003 Disco 2 Td5 (16P)

Okay, alternator area is quite oily. I know there is a seal between the vacuum pump and the alternator itself, and there is also a small o-ring on the oil feed hose that goes between the top of the engine and the vacuum pump. Are either of these two spots where the oil is likely leaking from?

Does anyone know what these part numbers are - small o-ring (assume viton?) and the seal? The short stubby vacuum pump oil drain hose is hard - can it be replaced? Does anyone know if it is available separately (might also get a small jubilee clip for it), or what the specs on it are?

often its wear in alt bearings,so unless its a hose or pipe fitting replace the unit

jamesmartin said:

often its wear in alt bearings,so unless its a hose or pipe fitting replace the unit

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Okay, seen a second-hand Denso working alternator from a 2003 Disco Td5 that has done similar mileage to mine (260,000km) for sale for 70AUD (38.50GBP) that I can pick-up locally tomorrow - obviously I could still be in the same boat in a short time though (at the very least the brushes would be almost worn out just like mine). Just cannot afford a new Denso unit though - c.590AUD (325GBP) delivered from a good online supplier here in Australia. From Paddocks in the UK it's AUD385.73, but then with shipping and tax I get AUD522.24 (287GBP) - save 38GBP, but of course at least a 10-day wait!

Maybe I can just swap out mine with the second-hand one and then take my time to replace the three bearings, brush box, rectifier and regulator on mine (original unit with 260,000km)?

Seen new unit from China (aliexpress) - "maxpeedingrods Dig Store":

https://www.aliexpress.com/item/100...earchweb0_0,searchweb201602_,searchweb201603_

This is 225.79AUD shipped (124GBP) - actually shipped from one of their overseas warehouses - one in Australia.
The Denso is 590AUD, so the copy is just over a third of the price! Worth the risk, and I keep my current unit for parts?

Any thoughts?

jamesmartin said:

often its wear in alt bearings,so unless its a hose or pipe fitting replace the unit

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Brushes (originals) were worn down as you'd expect, but looks like the rear slip-ring is gone! Bearings and the rest all looked good (tested rectifier and windings). The rear carbon brush was worn down around 2-3mm more than the front one, and it looks like that was because of oil/grit acting like cutting paste - hence the copper particles in the sludge! Oil and grit had got in through the back tin cover at some point!

Will get a second-hand alternator and a new brush box and keep my old one for spares (regulator and rectifier). Apparently you can fit slip rings, but I don't solder! Maybe a future project.

Moral - keep your engine bay clean!!!

Intestinalworm said:

Brushes (originals) were worn down as you'd expect, but looks like the rear slip-ring is gone! Bearings and the rest all looked good (tested rectifier and windings). The rear carbon brush was worn down around 2-3mm more than the front one, and it looks like that was because of oil/grit acting like cutting paste - hence the copper particles in the sludge! Oil and grit had got in through the back

View attachment 235400

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Love the picture!

So there was no leak from the vacuum pump?

PopPops said:

Love the picture!

So there was no leak from the vacuum pump?

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Hard to tell!!! Nothing obvious! Haven't taken the vacuum pump off yet as I was a bit disappointed when I saw the rear slip ring!

I might learn to solder (not sure if I have to?) in order to fix the slip rings, in the meantime I'll pick-up a second hand working unit and put a new brush box in it - seems like the best option???

Spoke to an auto electrician on the phone and he was disgusted with how things have gone - he said he feels sick when he sees all the good parts that just get thrown in the bin! The throwaway society has gotten out of control - I was always told that reuse is better than recycle (or landfill!). No one fixes stuff anymore - they just throw stuff out and get a new one - luckily medicine/surgery hasn't gone that way yet!!!

Intestinalworm said:

Spoke to an auto electrician on the phone and he was disgusted with how things have gone - he said he feels sick when he sees all the good parts that just get thrown in the bin! The throwaway society has gotten out of control - I was always told that reuse is better than recycle (or landfill!). No one fixes/repairs anymore - they just throw stuff out and get a new one!!!

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It would be a huge shame to throw away the alternator just because of worn slip rings.

Many many years ago I replaced the brushes on wifey's Renault 11 alternator. A few thousand miles later the red light was on again. This time I found a slip ring that had worn all the way to the non-conducting material below. If I remember right, it wasn't much deeper than in your photo. No idea though if Denso slip rings are thicker.

There are a number of places in the UK which rebuild alternators etc, particularly for the "boaties". Possibly similar in Australia?

Good luck, I hope it doesn't go into the bin.

Intestinalworm said:

Hard to tell!!! Nothing obvious! Haven't taken the vacuum pump off yet as I was a bit disappointed when I saw the rear slip ring!

I might learn to solder and fix the slip rings, in the meantime I'll pick-up a second hand working unit and put a new brush box in it - seems like the best option.

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Solderin is easier than weldin!
(Well sometimes!)

Picked-up a used and tested alternator for $75 (came off a wrecked Landy lying in a shed up in the country) - slip rings are good and no oil on it anywhere; it had two auto electrician stickers on it, so has been out and sent to the auto electricians twice in its life (mine has never been out of the vehicle since purchased new in 2003). The brushes are also around 15mm long (evenly worn), whereas my original brushes were unevenly worn (refer badly worn outer slip ring) - one about 5mm and the other about 8mm long. See below old and new ($75 alternator I picked up).

The second-hand alternator had no oil whatsoever covering it - looks in good nick - just dusty on the outside and inside so I cleaned it up - cleaned case, regulator, rectifier (now a nice grey) and the brush box.


All nice and clean inside.


And here's the back case - the old oil-covered unit (with the worn outer slip ring) is at the side.

Intestinalworm said:

The second-hand alternator had no oil whatsoever covering it - looks in good nick - just dusty on the outside and inside so I cleaned it up - cleaned case, regulator, rectifier (now a nice grey) and the brush box.

View attachment 235890
All nice and clean inside.


And here's the back case - the old oil-covered unit (with the worn outer slip ring) is at the side.

View attachment 235891

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That was a good price for one in such good condition!

PopPops said:

That was a good price for one in such good condition!

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Wreckers selling for AUD 200 - 250 over here - not reconditioned, just "as is" condition; I asked one seller if he could check the condition of the slip rings and he said I could check for myself after I bought it! The used units are mainly purchased if someone (private or second-hand dealer) just has to get the Landy working for a quick sale. If you want to fix your problem and do a bit more driving you buy a new Denso (AUD 550 - 600). Seems there are no reconditioned alternators out there anymore from what I could see - don't think auto electricians replace slip rings - not worth it, given they charge c.AUD 120 per hour for labour! Anyway, this unit had no oil covering it as I said, and was from a country property - wrecked vehicle that had been sitting in the garage for several years and now being stripped. The good thing is that two stickers on the case showed it had gone to an auto electrician on two occasions back in the day (last time about 7 years ago). No play on bearings (brushes could possibly have been replaced), and I was pleased that the slip rings had a good bit of meat on them.

I've done 265,000 km (165,000 miles) with the 2003 D2/Td5 and the alternator/vac pump is all original - I've never touched it in all that time; I got a good run out of the original brushes until I had this oil issue! Anyway, could see no sense in buying an alternator of the same vintage as mine, however, I was lucky to find this one at a good price as it had been out to the auto electrician twice in its lifetime (although the actual work done on it was not recorded) - figured it was worth a punt.

Looks like brushes (brushbox), regulator and rectifier can be easily replaced and sourced (eBay) - c.AUD 150 for the set of three. Bearings (three off - two for alternator and one for vacuum pump) are also not too much of an issue - any bearings/seals supplier should have a replacement, but a bearing puller is required, and a bearing press is an advantage, so that might make it slightly difficult for some, including myself. The lip seal between the vacuum pump and alternator (Denso 081103-0080) is also a Toyota part number 29341-64130, easily replaced, and can be sourced on eBay, or slightly cheaper by picking-up from a Toyota dealer spare parts counter here in Australia (pick-up for c.AUD 45); there is also a vacuum pump seal (Denso 081103-0060) behind the vacuum pump bearing. Looking around I came across Woodauto.com in the UK - they sell both seals:

N/D 081103-0080 (SAS 7481 superseded by part no. WOOEC3947K) - lip seal between vacuum pump and alternator (found it here on a Japanese website for Toyota parts, https://www.amayama.com/en/part/toyota/2934164130, and also available from Toyota (Sydney, Australia warehouse), but scarce!

N/D 081103-0060 (SAS 7480 superseded by part no. WOOEC3947G) - seal behind vacuum pump bearing

You can also source slip rings (I believe these are the correct ones) - I saw them at Baxters.com.au (parts wholesaler) here in Australia:

Nippondenso 8.8 X 14.5mm (Item No. NSR1; cross-references 28-82853 and SR77).

At this stage I wouldn't feel competent enough to change slip rings though!!!

PopPops said:

Love the picture!

So there was no leak from the vacuum pump?

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Suspect oil leaking from the oil feed hose (YKL100120) and/or the banjo bolt area. The "new" used alternator/vacuum pump has no oil on it whatsoever, so that's good - indicates internal seals were fine. I also checked the camshaft seal area again at the front of the engine - spotless, but this had leaked oil around 12 months ago before I changed it. I just bought two new copper crush washers from an LR service centre for a couple of dollars each to ensure a good seal at the banjo bolt.

Didn't know this, but the new crush washers are not flat - they look like a wheel rim! Sorry, I'm not an expert on these things! I understand these same copper crush washers (ADU6847L) are used on the turbo to stop/reduce oil going into the intercooler.

I'm going to clean the area of the engine around where the alternator/vacuum pump was, and monitor after reinstalling the alternator/vacuum pump. If there's still oil leaking somewhere then I'll be suspecting the oil feed hose, or even the short oil sump return hose I guess. A new oil feed hose (YKL100120) is not cheap at all - c.AUD 250 for genuine L/R, so, if necessary, I might look at taping over the current hose with self-fusing silicone tape as a remedy if it is the source of the leak? Has anyone ever tried that? Any comments?



Excuse the dirty finger nails!!!

Engine area around alternator cleaned (never been cleaned before) of oil with a citrus foaming degreaser and old rags.
"New" used alternator tested (out of the vehicle) with multimeter and all seems good:

Rectifier Bridge (6 diode pack) - tested on multimeter diode setting and current flows in only one direction between each of the three stator coils and the alternator positive terminal (B post) - swapping the leads results in no reading, so looks good there? Will also test when running to see how much AC is being sent to the battery (hopefully negligible)?

Rotor - there is continuity between the two copper slip rings and 2.9 Ohms resistance; also no continuity from shaft to slip rings - so all good here as well I'm presuming?

Stator - three windings all test good (minimal resistance between them) and no continuity between windings and body

Regulator - as I only have a multimeter, I will test when the alternator is installed and the engine is running - looking for 14.2V - 14.7V

Brushes - lubricated with WD-40 - move easily and protrude around 9mm into the brush box holder


I found these two videos particularly helpful:



(video at around 11.05 details basic bench testing of the alternator)


This article is also very good for beginners such as myself:

https://axleaddict.com/auto-repair/...the alternator.,there should be no connection.

Later on I'm going to see if I can clean the old (my original Denso) alternator windings with mineral spirits and get it working again. The problem will be slip rings - I have to find a guide on how to replace them!

Intestinalworm said:

Engine area around alternator cleaned (never been cleaned before) of oil with a citrus foaming degreaser and old rags.
"New" used alternator tested (out of the vehicle) with multimeter and all seems good:

Rectifier Bridge (6 diode pack) - tested on multimeter diode setting and current flows in only one direction between each of the three stator coils and the alternator positive terminal (B post) - swapping the leads results in no reading, so looks good there? Will also test when running to see how much AC is being sent to the battery (hopefully negligible)?

Rotor - there is continuity between the two copper slip rings and 2.9 Ohms resistance; also no continuity from shaft to slip rings - so all good here as well I'm presuming?

Stator - three windings all test good (minimal resistance between them) and no continuity between windings and body

Regulator - as I only have a multimeter, I will test when the alternator is installed and the engine is running - looking for 14.2V - 14.7V

Brushes - lubricated with WD-40 - move easily and protrude around 9mm into the brush box holder


I found these two videos particularly helpful:



(video at around 11.05 details basic bench testing of the alternator)


This article is also very good for beginners such as myself:

https://axleaddict.com/auto-repair/DIY-Auto-Service-Alternators-Diagnosis-and-Repair#:~:text=be no connection.-,The stator is the fixed ring inside the alternator.,there should be no connection.

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Mate, after describing all these tests you've done, i think you are taking the p!ss a bit calling yourself a "beginner"!

Stanleysteamer said:

Mate, after describing all these tests you've done, i think you are taking the p!ss a bit calling yourself a "beginner"!

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Learned so much from you and others, then I read up a bit and gain enough confidence to have a go! Hoping to graduate to intermediate soon! Love Land Rovers now! Real Land Rover drivers fix ‘em themselves eh!

Intestinalworm said:

Learned so much from you and others, then I read up a bit and gain enough confidence to have a go! Hoping to graduate to intermediate soon! Love Land Rovers now! Real Land Rover drivers fix ‘em themselves eh!

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Be interesting to put up a poll along the lines of how we all learned.
I like you am mostly self-taught. but was lucky to have friends and neighbours with knowledge.
Did NOT come down from my Dad, as apparently happened to quite a few. And moved too far away from my Grandpas, who were both engineers, at an early age.
But the net has really made things a lot easier for all of us.