Omega Owners Forum
Chat Area => General Car Chat => Topic started by: albitz on 13 November 2012, 13:33:17
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My Diesel Cavalier has the vac pump on the rear ofthe alternator which has an oil feed for the vac pump bearings.
It sprung an oil leak a week or so ago so I have just fitted a new oil seal which I thought would cure it. Just fitted the new seal and put it all back together but its still leaking as bad as ever.
Having looked closely at the leak it looks like it could be coming from the body of the alternator itself rather than the join between the vac pump and alternator.This doesnt really make sense to me as I would have thought oil would be able to get into the alternator.
Im a tad confused and frustrated as its a bit of a pita to take it all back off again,so dont want to do that unless Im pretty sure I know how to cure the problem this time.
Anyone got any previous experience of this please ?
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Albitz
Have you checked the feed banjo seals and the return pipe. If the oil is coming out of the alternator then you have big problems as there shouldn't be anyway for the oil to get in there
Andy
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Checked them Andy,it isnt coming from there.Its definitely coming from near the join between vac pump and alternator,but the join between the two looks dry. :-\
I suspect Im going to have to take the alternator off the car again (3rd time) and inspect things very closely.
Got painting & decorating to do today :'(......so will have to wait until tomorrow.
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I know they are expensive as I had to change mine Albs.
At the time we had a Classic Range Rover too that a replacement alternator cost £50. My Cavalier TD £175 at the time
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Is it not possible that the vac pump is sucking in oil from somewhere?
Just thinking. There'll be an air outlet on the pump. If oil is getting into the vacuum lines, it'll come out there. Not sure where the oil will be coming from. Not losing brake fluid into the servo, I suppose?
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The vac pump has its own oil feed & return Kevin,so that where the oil source is. :y
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Hmmm, dependent on the vac pump type (e.g. rotary vane) then the oil supply is required in order for the vanes to make an effective seal and produce the vaccum. So when the vanes and rotar wear the oil expelled out of the vent (as there will be vent to atmosphere) will increase quite a bit. could it be this?
If its a basic diaphram setup then things are very different (but it would not need an oil feed)
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Will have a closer look when I remove it again,but it has an oil feed and a larger pipe which is apparently the oil drian back into the sump.No vent to atmosphere as such that Im aware off,but another pipe goes out the top to the servo to provide the vacuum. Splined shaft comes out the rear of alternator and inserts into the pump to drive it.Dont know any more than that tbh.
Could feasibly be wear as you suggest,although it seemed to start suddenly and leaks from one particular spot,which is difficult to see with it on the car and the engine running.
Im thinking when I remove it this time to resist the temptation to clean the oil off first,but leave it as is and hope the oil trail will provide a clue.
Guessing drain back to sump could also provide vent to the atmosphere via breathing system ? If so,it isnt leaking from there,but coming out from somewhere alse close to the join between pumpand alternator,but doesnt appear to be actually coming from the join. Need it off the car again I think and then have a very close look.
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Oh, OK. If the pump has its' own oil feed then that's probably the source.
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Well Ive found where the oil is leaking from but dont know why.Theres a little hole in the alternator visible in the pics,and that is where its coming from. Im wondering if there shoud be a little grubscrew or similar in this hole and it has fallen out. :-\
I suppose it will need info from someone fimiliar with these units. :(
(http://i1238.photobucket.com/albums/ff500/Albs59/DSCF1652.jpg)
Piece of red wire poking i to the hole
(http://i1238.photobucket.com/albums/ff500/Albs59/DSCF1654.jpg)
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Is that the face of the alternator where the pump bolts on?
If so, I'd say it's leaking out of the front face of the pump and that hole is there to drain any leakage so it doesn't end up in the alternator.
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The machined face visible just above the hole is where the vac pump sits (attached by 3 bolts to the rear of the alternator) the oil seal ive just replaced (O-ring) is visible in the pic too.Then there is the splined shaft which comes from the alternator and drives the vac pump. I had assumed the O ring seal would prevent oil from leaking into the alternator as well as escaping to the outside world.
I have just been and had another look however and the seal wouldnt prevent oil from getting into the alternator.I would assume theres another seal inside the body which is supposed to do that job,so that is probably where the problem lies and I very much doubt its a service item.
So,I have a feeling the alternator may just be inside its warranty in which case I will try and get a replacement.If not,a new one would be more than the car is worth so I might rig up some sort of catch tank arrangement to catch the leaking oil.
The car had about 9 months MOT left and then it will probably be going down the scrappy (hopefully to be replaced by a Merc 190D) so Im not going to throw money at it.
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Having said all that,the hole isnt at the lowest point of the alternator when its on the car,its actually almost at the midway point between the highest & lowest points,so maybe it isnt a drain hole ? :-\
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ISTR that's where mine leaked from, but it's a long time ago ::)
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I would be interested to know why it leaks from there,but I may never know. ;)
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Is there not a seal where the shaft passes into the vacuum pump? If not, it'll be in the alternator, but I suspect it's had it, wherever it is.
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Is there not a seal where the shaft passes into the vacuum pump? If not, it'll be in the alternator, but I suspect it's had it, wherever it is.
No seal there Kevin,so it must be internal. I suspect your suspicion is bang on. Rig up a catch tank is the way forward I think. ::) :D
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Any id numbers on the pump or try calling a local alternator refub place as the pumps can be got via the aftermarket on thier own
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Pretty sure Ive now found the problem.Dismantled the alternator and there is indeed an oil seal which should prevent oil from entering the alternator from the vac pump. As Kevin suggested it would appear that this is no longer doing its job so the oil is getting past it and then draining back out of the small drain hole.
I will enquire,but I doubt this seal available from VX is its an internal part of the alternator.
Will do as you suggest though Mark and contact refurbers to find out if I can get a seal from one of them. :y
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Pretty sure Ive now found the problem.Dismantled the alternator and there is indeed an oil seal which should prevent oil from entering the alternator from the vac pump. As Kevin suggested it would appear that this is no longer doing its job so the oil is getting past it and then draining back out of the small drain hole.
I will enquire,but I doubt this seal available from VX is its an internal part of the alternator.
Will do as you suggest though Mark and contact refurbers to find out if I can get a seal from one of them. :y
What type of seal? Just an O Ring? ???
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Nope.More a standard type oil seal.I will post a pic of it later. :y
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If you can get it out, call these people: http://simplybearings.co.uk/shop/
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Already got it out.That link looks hopeful,thanks Aaron. :y
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Have you checked the warranty yet Albs? I feel sure the alternator came with a 2 year warranty which should still be valid... :-\
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Will have a look shortly James. I looked a few weeks ago and it didnt have long left to run,so hopefully I might be lucky. :-\
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The warranty runs out..........................................................today. ::) ;D
Just spoke to the supplier and they said if I bring it in on Monday they will swap it for another one. Result. :)
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The warranty runs out..........................................................today. ::) ;D
Just spoke to the supplier and they said if I bring it in on Monday they will swap it for another one. Result. :)
What is it they say about the luck of the Irish... ::)
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Begorrah bejaysus sure aint that the truth now to be sure. ;D ;D
Cut it a bit fine though. ::) ;D
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Begorrah bejaysus sure aint that the truth now to be sure. ;D ;D
Cut it a bit fine though. ::) ;D
Result :y
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Picked up my nice shiny new FREE alternator this afternoon,so should be back on the road and leak free if the weather stays dry tomorrow. :)
Thanks for all the advice everyone. :y
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Picked up my nice shiny new FREE alternator this afternoon,so should be back on the road and leak free if the weather stays dry tomorrow. :)
Thanks for all the advice everyone. :y
Touch! :y
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Didnt include vac pump though.I might ask for a refund. ;D
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I've just taken one off a car - alternator (not charging) + vac pump.
yours for nowt if you want it........
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Will bear that in mind thanks woody. :y
I fitted the vac pump to the new alternator and fitted it to the car. It pumped out oil like a BP deep sea well.Ive had a quick look and suspect the fettler in the chinese foundry didnt grind the cutouts deep enough to allow the vac pump to sit tight against the rear face of the alternator.Im going to try to sort that at work tonight,although I probably wont be able to fit it and test it until Saturday.
If I cant sort it I will get in touch. :y
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Acted on my suspicion and spent 5 minutes with a file correcting things so that vacpump was definitely sitting tight against the rear face of the alternator.Only slept 3 hours between shifts today so had time to refit it to the car.
Started the engine and - it pumped out oil just the same as it did last time. I now have no idea why its doing this so its back to the drawing board. Will take it back off the car yet again and have another look.Then may have to drop a PM to 2WOODY.
Im absolutely sick & tired of it now.Need to change dispack & stat on the Omega,but have been trying to fix this first. :'(
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Update.
Took the alternator off the car again last week.Took it to the supplier and explained the problem.He had never heard of anything similar and had no idea why it should happen.
Took the vac pump off again cleaned and inspected everything.Carefully reassembled and fianlly managed to get it back on the car 10 minutes ago. Still leaking like a sieve.Its not leaking at the joint between vac pump and alternator as I thought,but leaking from the little "drain" hole,which is exactly the same place as the old one was leaking.
The oil must be being forced past the oil seal in the alternator,rather than a failed oil seal in the alternator,as I had assumed was the problem with the old alternator.
Why though ? Im at a loss to explain the problem or have any clue how to fix it.I really need the car back on the road though.
Might be worth speaking to 2woody to see if its worth having his vac pump to try on my new alternator. :-\