Alternator Vacuum Pump for power brakes/clutch

[Aussie_Kymbo]

G'day everyone. I have a landcruiser, HJ60, 2H diesel, 5 speed, great vehicle. A couple years ago while traveling around I needed to have the alternator replaced with a newbie, all great. These alternators if you weren't aware of have a vacuum pump mounted at the back thats driven by the alternator shaft. Well out of the blue the vacuum pump started to fail and within no time I had nil vacuum for brakes/clutch. The pump was removed from the alternator and I discovered to my shock it was as dry as the preverbial, when it should have had oil in it as its fed by an oil line from the motor and then a drain at the bottom lets oil drain back to the motor.

What I need to know is this. Does the oil draw up the oil line by vacuum from the pump, ie oil is sucked up to the vacuum pump as a result of the vacuum inside it therefor lubricating it. This is the version I have always been led to believe!

Or is it fed under pressure from the motor and then drained back to the motor once it reaches the bottom of the vacuum pump. This oil feed comes into the alternator housing and then into the vacuum pump, I believe it lubes the rear bearing of the alternator also.

My motor was rebuilt in "06 and runs great, never gets hot, great oil pressure even at idle, this being so, I am even more willing to believe what I have always believed which is that the vacuum created in the pump for the brakes/clutch sucks oil up to the vacuum pump also and lubes it.

Next question, the 2 oil lines that come from the motor to the back of the alternator/vac pump, is there a right way and wrong way to connect them, maybe the electrician that installed the alternator hooked the oil lines up wrong. 1 oil line comes from a larger trunion conection off the engine block and the other comes from a smaller trunion conection from the engine block. Does anyone know, or maybe you could have a look at yours if you have one, which oil line should go into the alternator housing and which one comes from the base of the vacuum pump.

Thanks heaps in advance for anyone who can let me know any parts of what I need to know.

Cheer's

Kymbo B)

[01 VEY]

Hey Kymbo

Sounds like the vacuum pump has been run dry.

First thing I would check is the bolt holding the 'Banjo' to the pump. I sell these alternators quite often and have heard of a few that have been fitted with only the packing bolt provided in the pump to keep dust and other junk out during shipping.

Make sure that it is hollow through the shaft of the bolt with a hole drilled laterally for oil to come through. Also check that the hose has not de-laminated internally as this will also block any oil from getting to the pump.

As far as I understand the oil is fed from the engine oil pressure to the pump. Once it has done the lubricating job it is discharged along with the air used the create the vacuum back into the sump via the bottom pipe. I absolutely don't recommend taking the small pipe off the alternator but I am certain the engine will spit out a few litres a minute onto your floor if it disconnected. This will not only cost a lot to clean up but will also cost you for a drum of new oil. Definately not worth trying to prove this one.

The smaller of the hoses is the pressure into the vacuum pump. This is usually fitted onto the alloy casing. Oil then goes through the pump vanes with the air.

The other is the dump pipe back to the sump.(see attached picture) I hope it uploads.

I trust that this helps

Regards

Mark

Edited January 22, 2011 by 01 VEY

[Aussie_Kymbo]

Cheer's Mark. Thanks for the reply, I really do appreciate it and any more also.. It is clear that it ran dry..lol, I was horrified when I opened it and saw the inside of the vac pump. When the auto electrician fitted the new alternator he told me he also fitted new rubber hoses to the oil supply line fittings that connect both to the alternator (oil feed in) and engine block ins and outs, as the drain back just pushes on and is hose clamped. I am going to remove both today and check they havent started to come appart inside, I know this can and does happen, especialy if he used the wrong type of hose for it.

What I really need to know is this. What connection from the engine block feeds the oil to the alternator, if anyone can tell me I would be really appreciative of the info, as I said, one conection at the engine block has a large fitting and the other a small fitting, logic tells me that the large fitting would be drain back from the vac pump to the engine, and I have this thought that maybe the auto sparky has got them on the wrong way as he told me they were both removed and had new rubber hoses fitted, I am sure there would be a right way and wrong way.

I had a mate here and after the vacuum pump had been removed I told him to watch the both oil lines and tell me what oil line if any had oil comming out when I start the engine. There wasnt any but I am going to repeat that with the oil feed lines off the engine all together, not a lot of oil will be lost as my mate will yell the moment he see's a flow from either point, and I guess if no-one can give me an idea of what conection is the outlet and what one is back in the engine I guess Ill find out then..lmao.

I again also spoke with a bloke lastnight and he reassures me that the oil is brought to the vacuum pump through the vacuum created in the pump, not under pressure from the engine, drawn into the alternator, then into vacuum pump and then expeled with air back into the engine. I need to really get this right as I am replacing the entire alternator today and I dont want to make any mistakes with lubrication hook ups.

Im not saying the bloke I spoke with is right or wrong at this point, but at the moment its evenly ballanced, drawn up from vacuum or fed up under engine oil pressure.. ...... :D

I again wait in anticipation for even more goood info, and again, Mark, thanks so much for your input so far.

Cheer's

Kymbo B)

[01 VEY]

Sorry mate I am only a computer jockey and have to admit that I have not worked on a diesel Cruiser. The info I have is what I have picked up in the last 10 or so years talking to auto electricians and some personal research. As for me I'm happy to stick to the petrol fired enigines. It seems that many Japanese diesel motors started life as basic industrial engine and when fitted to a moving vehicle they found there was a needed to do something for the brakes. Hence the vac pump on the alternator. I hope there is a Toyota trained mechanic out there who can shed some light on the oil feed situation. Whatever happens you definately need the oil.

Good luck with getting it going

Regards

Mark

[Aussie_Kymbo]

Cheer's mate, no probs with how you got the info. I did get somewhere today though, this may be good for anyone else that reads this that needs to know the same thing. The alternator I picked up today did have the original oil lines on them and I now know what oil line goes where. The oil feed into the alternator (conects to the cast alloy alternator housing) comes from the small connector on the engine block, as I thought it would be, it made sense. I'll be looking tomorrow at mine to check if the auto sparky did it the right way.

Re the having to add a vacuum pump on the japanese comercials. The vacuum pump on diesels is very common as you can not take vacuum off the engine inlet manifold as you can with petrol motors, this is standard with all diesels, either a vacuum pump is on the alternator, or a seperate vacuum pump is driven by the fan belt or bolts onto the engine and is cam driven like a fuel pump, or a lot now are electric vacuum pumps (which I looked into as an option).

Anyway, now all I need to work out or find out is, is the oil brought to the vacuum pump from the vacuum created in the pump, not under pressure from the engine, drawn into the alternator, then into vacuum pump and then expeled with air back into the engine, or is it forced in from engine oil pressure and then expelled back to the engine from the base of the vacuum pump.

Cheer's anyway, again, thanks for your input.

Kymbo

[Aussie_Kymbo]

Just a quick update.. I called around, Toyota dealership, diesel engine business and Im still in the dark about how the oil reaches the vacuum pump, the gregories book is useless, gives info on rebuilding but no explaination. The Toyota place (very popular here) couldnt tell me, they said they cant even recall anyone ever having a problem with one so they couldnt really tell me, but, they will try to find out. The diesel engine place, again, very good reputation, 1 guy said it was drawn up from vacuum, he said its a vane pump (which I knew) and that it actually pumps oil up into and out of the pump, another guy there said no, its pumped up from engine oil pressure, when I hung up from them they were "discussing" the issue between themselves.

Please... , does anyone have the definate answer, with proof or explaination that is proof posative, I dont want to destroy another alternator/vacuum pump. If it is pumped up there from engine oil pressure, world war III will start with the place that rebuilt the engine.. , as I said, I have superb engine oil pressure, it's just not pushing out the hole in the block where the oil feed to the alternator/vacuum pump feed comes from..

Im not loosing my hair....YET...

[sharkman]

Hi, I may be a bit late with this reply for you but, oil is pumped under pressure from block to vac pump. I know this is the case as I had issues with my pump and fitted a new one, to be sure oil was getting up I had a mate run her while I watched with the line disconnected. definately pumps oil out. cheers.

[Aussie_Kymbo]

G'day. Well I am back and with a solution of sorts. Sorry it's been a while, yes the oil is pumped up under pressure I finaly discovered, but for some reason not on my engine, my next fight here is with City Dismantlers of Gepps Cross Adelaide, they did the entire engine full recondition in late '06 and Ive replaced now 4 alternators in that time due to same reasons, the vacuum pump has died. The original went south 7 months after I had the engine done, replaced with a "new" 1 from City Dis, 10 months after in Mt Isa that died, City Dis wouldnt send a new unit without my reciept even though I had spent a huge amount of $s there, and I spoke with the salesman that dealt with my engine recond, big argument there. Anyway, I got an alternator (new) in Isa and that is the 1 thats just died, same fault so there is a big pattern here and Ive had the oil lines off and no oil comes out when the engine is running, so there are issues there for sure.

To get around this an oil feed has been taken from an oil cooler line using a "T" piece, that feeds oil under pressure to the alternator and all is good again.

So, soon it is off to City Dismantlers of Gepps Cross Adelaide to ask them some serious questions. Needless to say, I do not deal with them anymore since they screwed me with the needing my reciept etc when their alternator died in Mt Isa. I'll post their response on here if and when I get one.

Cheer's and thanks for all the input.

Kymbo

[01 VEY]

Hey there Kymbo

Good to hear that you have a solution of sorts to get you back on the road. It sucks that the engine rebuilders are a bit dis-interested in helping you to resolve the problem. I think they are lucky to have had a customer who is as reasonable as you seem to be. The temporary fix sounds good but there must be something a bit wrong in there for the lack of oil pressure. I guess that will be something for the next guy who pulls the engine down.

When I was younger I rebuilt a Holden Red motor and put the big end bearing shells in on the wrong side and ended up not having the oil squirting up onto the piston and gudgeon area. That was I think what made it seize up on me.(Monumental beginners stuffup) It was explained to me by an engine machinist that many engines rely on bearings which have a groove along othem to supply il to other parts of the engine. Makes me think that they may have inverted a pair of main bearing shells or possibly used a shell meant to be fitted in another journal. Below is a good picture of what I mean. Even though some of the holes may be in the same place you can see there is one with 2 holes for lubrication to get to something else in the engine.

I hope all goes well with getting something done about this.

Regards

Mark

[Aussie_Kymbo]

Yeah I hear ya Mark. I used to rebuild engines and build the occasional racing engine so I know the internals and how they work very well. The only reason I didnt do my 2H was I now have a severe back injury and just cant do the heavy stuff. My engine has amazing oil pressure and It's been running without any other issues since begining of '07. It could just be a bit of gasket sealer (if they used any) that has blocked that particular oil outlet, Im not sure but this following week I will be going in to speak with the boss of that place and if I get no joy will speak with professional mechanics about the problem and then take it back to that boss, if no joy then I will be contacting Consumer Affairs with the info, and if the consensis says that the engine builder did it wrong I'll push for a tear down and repair at their expense.

I'll keep ya's informed.

Cheer's

kymbo