Vacuum fuel pump leaking oil

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Eli's fb
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Vacuum fuel pump leaking oil

Post by Eli's fb »

Hi ,bought my Fb about 18 months ,vacuum fuel pump was leaking oil from the beginning, bought a rebuild kit, gave to a mechanic ,got a good reputation with holdens, still leaked after a while from the breather hole ( I think) for the vacuum.Bought a nos stock one ,thought save me changing fuel pump, wiper motor etc. Lasted about 200miles started leaking oil out of the breather hole, has someone gone through this, any advice?
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FJWALLY
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Re: Vacuum fuel pump leaking oil

Post by FJWALLY »

can you take some pics and post up Eli?
The fuel pump is mechanical not Vacuum as I understand it.
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Errol62
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Re: Vacuum fuel pump leaking oil

Post by Errol62 »

Eli
Vacuum wipers were superseded in EK and a lot of people have upgraded earlier cars using the EK motor. Hence knowledge of the vacuum setup is now limited. Not to say that you won't get some advice on here. The FE FC forum is also a good source of information. Good luck with it.
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FJWALLY
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Re: Vacuum fuel pump leaking oil

Post by FJWALLY »

Errol62 wrote:Eli
Vacuum wipers were superseded in EK and a lot of people have upgraded earlier cars using the EK motor. Hence knowledge of the vacuum setup is now limited. Not to say that you won't get some advice on here. The FE FC forum is also a good source of information. Good luck with it.
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Clay

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Vacuum wipers or fuel pump?


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Brett027
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Re: Vacuum fuel pump leaking oil

Post by Brett027 »

I guess NOS could mean oil seals have deteriorated, but leaking oil seals would put oil on underside of diaphragms- have you opened up and had a look? I haven't got a pump in front of me, but is the breather hole on the pump body between the fuel and vacuum pump diaphragms? If so, its not going to be seal related. Is motor breather blocked by any chance? Its a long shot but just by chance, is the engine/pump join gasket the right size? If the gasket was forming a lip at the bottom that may prevent oil from draining back into sump as it should. Keep us posted please, these tricky problems make it all interesting. That's my coffee break over.
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ardiesse
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Re: Vacuum fuel pump leaking oil

Post by ardiesse »

A couple of photos of your fuel/vacuum pump showing where and how much oil it's leaking will be useful.

There are a couple of "gotchas" to watch for with the vacuum/fuel pumps.

First is engine condition. If your engine blows fumes out the breather pipe and oil filler cap, it'll tend to leak everywhere, and the fuel pump is one of those places.

Second is the mounting bolts. The bolt holes are drilled right through into the crankcase. I rebuilt the vacuum section of my FC's fuel pump, and then it leaked oil, which pooled up on the horizontal part of the vacuum section at the rear of the pump. The oil was leaking past the threads of the mounting bolts. Thread sealant cured the leak.

Third is gaskets. A lot of people use the gasket for the later fuel pump with the early fuel/vacuum pump. The later gasket causes oil to pool up inside the pump housing, and it leaks. The best thing is to use no gasket at all, instead a thin smear of Silastic. And with no gasket, you'll get another inch of mercury of vacuum out of the vacuum pump. It all helps . . .

Rob
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Re: Vacuum fuel pump leaking oil

Post by Eli's fb »

Hi,it's a leak on the vacuum side of the fuel pump, opened the original pump after it had been done up (rare spares kit). On the body of the pump, there is a manufactured groove where one of the vacuum valves sit,that is where I think oil is passing through. That leads to the hole on outside the pump. Took a couple of photos, thanks for the help so far
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Re: Vacuum fuel pump leaking oil

Post by Eli's fb »

Hi,can't seem to work out sending of pictures, but will try your suggestions Rob,thanks let you know
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Re: Vacuum fuel pump leaking oil

Post by Eli's fb »

Here's the photo's
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ardiesse
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Re: Vacuum fuel pump leaking oil

Post by ardiesse »

Photos are good. See where the oil's pooling up on the horizontal part of the housing just above the inlet pipe from the wipers? That's exactly the same as in my FC.

I'd suggest you need to seal the threads of the mounting bolts: remove the pump, ditch the gasket, spray solvent into the bolt holes, degrease the bolts, let dry, coat the bolt threads in Silastic, light coat of Silastic on the mating face of the pump body, reassemble and let the Silastic cure.

When you're removing the pump, undo the bolts a few turns, then turn the motor over by hand until the spring pressure's gone. It'll make reassembly much easier.

Rob
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Re: Vacuum fuel pump leaking oil

Post by Eli's fb »

Thanks Rob, just finished,wish I read that last bit of advice first, pump went on was abit tight. Also took Brett's advice on breather,giving it good soaking in diesel and going to finish it off in hot water. Let it set overnight. Let you tomorrow
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Re: Vacuum fuel pump leaking oil

Post by Eli's fb »

Hi, been raining pretty much all day, ran for 20 minutes in the shed, no leaks. Real test will be a good drive. Thanks everyone for their advice. Let you know how it goes
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Re: Vacuum fuel pump leaking oil

Post by Eli's fb »

Hi,went for a run yesterday oil came out of that hole, went for another today thought maybe some still left from before still came out. Got rid of the gasket and cleaned the oil breather on top of rocker cover (was dirty) noticed at high revs 🤣bit of bubbling in glass fuel bowl. Oil coming out of the hole where the red thing is pointing. Any ideas what to try? 2 pumps doing the same thing. Thanks
gpi
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Re: Vacuum fuel pump leaking oil

Post by gpi »

read what Rob said the other day. you should probably buy an EK, theyre great!

its the same problem. you have the same problem with 2 pumps. if you can solve the same problem on one pump you can fix the same problem on 2 pumps.
ardiesse
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Re: Vacuum fuel pump leaking oil

Post by ardiesse »

The hole you're pointing to in the photo is the outlet for one of the chambers in the vacuum pump. If oil's coming out of this hole, it means that the oil seal in the vacuum section is leaking. If so, then there should be a oil slick on the subframe member directly opposite the hole. Is there?

There's a guy in Queensland (Classic Carbs?) who has repair kits for the vacuum section of the fuel pump.

If you want to take the bottom cover off the vacuum section of the pump to confirm the oil leak, here's what to do -

First, take a couple of the attaching screws to an engineering supply place and get two 1" long screws in the same thread (10-32 UNC, I think). You'll need these to release the spring pressure in the vacuum section. Put the two long screws in opposite positions in the bottom cover, and finger-tighten them. Remove the other six screws, then back off the long screws bit by bit until the spring pressure is relieved. Put the bottom cover and spring aside. You will now see the diaphragm. Don't remove it, instead, gently peel it up off the housing and turn the fuel pump upright (fuel bowl up). If the oil seal in the vacuum section is shot, oil will dribble out from on top of the diaphragm.

Reassembly from this point is just a case of putting the coil spring and bottom cover back in place: put the two long screws in opposite positions and tighten them down bit by bit until you can get the short screws started, then remove the long screws and put the remaining two short screws in. Tighten all eight screws securely and re-install the pump.

If you can do that, then it's not much more trouble to remove the oil seal (undo two tiny Phillips screws on an angle which hold the seal retainer in) and unhook the diaphragm. But you'll need to get a repair kit for the vacuum section first.

Rob
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