How does the pump on the generator work?

[Boltass]

Can someone tell me how or direct me to somewhere i can study how the pump on the back of the generator works?
I have read through the "how to replace alternator carbon brushes" thread now that i need to replace them but im still scared to touch the generator since i really have no idea how that thing works.
A friend of mine guessed it was just a vacuum pump for the brake booster which made sense to me, however i dont get why there is a line going to the engine afterwards?
If the pump sucks from the brakebooster then pushes into the engine isnt it causing a bunch of unnecessary blow-by? I've been thinking about this since the oil stick keeps getting pushed up 2-3 inches out after every time i drive. Or this could just be caused by worn out cylinder rings.
I have been looking for a oil filler cap with a vent on it but this seems very hard to find since the one on my pup is made of rubber? Is this original? because the oil filler cap should theoretically just shoot of if there is enough blow-by?

I hopefully wont need to change the oil line going from the generator to the block now that im just swapping the carbon brushes, but i thought of replacing the alternator belt aswell while i was at it but now that i've seen how dangerous this oil line could be to look over im looking if someone knows if that would be needed. It was said in the carbon brush thread that it should be replaced if you ever need to move the alternator. But sourcing this part here in Sweden might be quite the challenge...

[Boltass]

https://www.autodoc.se/lauber/10926277? ... 1010728%29

When i ordered the brushes for the alternator i also ordered this regulator because it was both cheap and my pup has been acting a bit weird.
The last week or so its been charging irregularly (This is most likely due to the brushes being word out) But it has also been acting as if it is overcharging aswell...
I have a small 6inch subwoofer at about 600-800w that when i just start the car and drive does not really want to work well.
When i get up to about 60km/h the amplifier goes into protect mode, this happens whenever there is too much or too little voltage. And when i then turn ON the lights it starts working again. Then when i get to about 90 - 100kmh it goes into protect mode again. This to me is extremely odd since usually what happens is it will be in protect mode (from low voltage with a bad alternator / battery) up until you start driving the car since the alternator will start to charge more when driving.

This started happening about 2-3 weeks before the alternator stopped charging entirely, which was when i thought the carbon brushes were worn out. but the problem that persisted before this has been troubling me still... Could this be the fault of the alternator regulator? Is this even the correct regulator for the pup? Mine is the 1987 kb with the c223 engine.
Any help will be gladly appreciated.

[Red Truck]

I can't help with the pump issue (mine's a gasser; doesn't have that feature), but I can speak about the alternator overcharging. Years ago, I had an issue with my battery cooking and ultimately spewing acid all over the engine bay...what a mess. My alternator was charging fine, always putting out 17V....continuously, I later discovered. Seems the integral voltage regulator wasn't regulating, and was "stuck open', so to speak. Took me a while to figure this out, for like you, I assumed to see a lower charging condition for a defective alternator, not higher. I then got a reman unit from NAPA.
Does your local brand-name auto parts retailer offer exchange/rebuilt alternators? You'd get a new regulator, brushes, bearings, etc. Don't know if you can use Rock Auto; they offer that service. /R

[JoeIsuzu]

A friend of mine guessed it was just a vacuum pump for the brake booster which made sense to me, however i dont get why there is a line going to the engine afterwards?

That line is FROM the engine to the vacuum pump. If the pump did not have a steady supply of oil, it would self-destruct. It would probably seize up and shear the splines off its shaft. And without an oil bath, the vanes would not seal adequately to produce suction (vacuum).

If the pump sucks from the brakebooster then pushes into the engine isnt it causing a bunch of unnecessary blow-by? I've been thinking about this since the oil stick keeps getting pushed up 2-3 inches out after every time i drive. Or this could just be caused by worn out cylinder rings.

This should never happen. I don't know how your crankcase is vented, since you don't have a US truck. But our early ones had a very rudimentary oil separator, and vented to atmosphere via a "draft tube". Our 1984-1987 models got a more thorough oil separator, and then the blowby was routed back to the intake. If your dipstick is getting pushed out, you have a blockage in the ventilation system, apparently.

I have been looking for a oil filler cap with a vent on it but this seems very hard to find since the one on my pup is made of rubber? Is this original? because the oil filler cap should theoretically just shoot of if there is enough blow-by?

See my previous comment.

I hopefully wont need to change the oil line going from the generator to the block now that im just swapping the carbon brushes, but i thought of replacing the alternator belt aswell while i was at it but now that i've seen how dangerous this oil line could be to look over im looking if someone knows if that would be needed. It was said in the carbon brush thread that it should be replaced if you ever need to move the alternator. But sourcing this part here in Sweden might be quite the challenge...

If you so much as flex it, to see if it is still flexible -- you risk breaking it. It can crumble internally, but the fabric jacket on the outside hides the failure. This line should be replaced preventatively. How do you know if it has failed? Your engine starts knocking, and seizes up. Looking back, you see a trail of oil on the road.

Jack

[Boltass]

Seems the integral voltage regulator wasn't regulating, and was "stuck open', so to speak. Took me a while to figure this out, for like you, I assumed to see a lower charging condition for a defective alternator, not higher. I then got a reman unit from NAPA.
Does your local brand-name auto parts retailer offer exchange/rebuilt alternators? You'd get a new regulator, brushes, bearings, etc. Don't know if you can use Rock Auto; they offer that service. /R

This could be the case, however i have no idea where the "integral regulator" is, what it looks like or how it works :/ need to do more research.
And there is absolutely zero chance of finding someone here in Umeå that does alternator rebuilds, i was just thinking of ordering a new one, seen some on Autodoc but Rockauto might have one aswell?

A friend of mine guessed it was just a vacuum pump for the brake booster which made sense to me, however i dont get why there is a line going to the engine afterwards?

That line is FROM the engine to the vacuum pump. If the pump did not have a steady supply of oil, it would self-destruct. It would probably seize up and shear the splines off its shaft. And without an oil bath, the vanes would not seal adequately to produce suction (vacuum).

If the pump sucks from the brakebooster then pushes into the engine isnt it causing a bunch of unnecessary blow-by? I've been thinking about this since the oil stick keeps getting pushed up 2-3 inches out after every time i drive. Or this could just be caused by worn out cylinder rings.

This should never happen. I don't know how your crankcase is vented, since you don't have a US truck. But our early ones had a very rudimentary oil separator, and vented to atmosphere via a "draft tube". Our 1984-1987 models got a more thorough oil separator, and then the blowby was routed back to the intake. If your dipstick is getting pushed out, you have a blockage in the ventilation system, apparently.

I hopefully wont need to change the oil line going from the generator to the block now that im just swapping the carbon brushes, but i thought of replacing the alternator belt aswell while i was at it but now that i've seen how dangerous this oil line could be to look over im looking if someone knows if that would be needed. It was said in the carbon brush thread that it should be replaced if you ever need to move the alternator. But sourcing this part here in Sweden might be quite the challenge...

If you so much as flex it, to see if it is still flexible -- you risk breaking it. It can crumble internally, but the fabric jacket on the outside hides the failure. This line should be replaced preventatively. How do you know if it has failed? Your engine starts knocking, and seizes up. Looking back, you see a trail of oil on the road.

Jack

Okay then it makes more sense of how the alternator works, i managed to change the carbon brushes and it is charging up to 14.4v fast and steady now.

I also think i have seen that draft tube you mentioned, it goes down by the passenger side of the engine and down? Kind of like on a dirtbike, ive seen this and thought of it but never looked to where it ends. It could certainly be blocked off but that might be the oil separator you mentioned. I did change oil not too long ago and let it pour out over the night so if there is something blocking it it would most likely not be oil? Or maby that oil separator does not get drained fully when just removing the drain plug. I dont know which i have tho, if its the new or old one since its again an 87.
Shouldnt it be possible to "feel" air coming out of there when its running? When cold there should be more blowby right?
I am slightly worried since it does not make sense for the dipstick to keep jumping out like that.

[JoeIsuzu]

Again, I don't know how the crankcase is/was vented in your market's engine.
If you have a draft tube, the oil separator is the part that the draft tube is attached to, on the pushrod galley.
If you do not have a draft tube, the oil separator is a box on the top of the valve cover, with hoses attached (at least, that's how it is on the US version). I'm told the later ones are more prone to clogging up than the older ones that used a draft tube.

I don't know if the draft tube should have enough coming out of it to feel it.

I know nothing about voltage regulators, so I'll have to pass on those questions.

Jack

[Red Truck]

In response to an 'integral regulator' mentioned above, I'm referring to the voltage regulator that's built into the alternator. It's the same device you provided the link to. And, I just looked at Rock Auto, they indeed say they accept Swedish Krona (SEK) and ship there as well. But it sounds like you got it going again, so congrats! /R

[isuzu Specialities]

The vacuum pump is there to create vacuum required for your brake booster. Its a independent unit that simply mounts to the rear of the alternator & is driven by the back side of the alternator stator shaft. The vacuum pump is lubricated with engine oil supplied by the little 6mm-ish tube connected to the engine block. The return of the engine oil is performed by the vacuumed pumps discharge hose that is also connected to the engine.

The vacuum pumps air flow into the crank case is minimal at best and it's also only momentary. When the vacuum system is at max vacuum the flow of the vacuum pump is just about zero. Only when you let off the brake pedal does the vacuum pump begin work for about 3 seconds. The amount of volume the pump moves is so small it will not affect blow by of your engine.

The alternator is repaired like another alternator once you remove the vacuum pump from the rear. Worn brushes have a symptom of erratic alternator output, Overvoltage, under voltage or overcharge/undercharge is a symptom of a failed regulator. Low output and radio interference is a symptom of a failed rectifier.

[Boltass]

In response to an 'integral regulator' mentioned above, I'm referring to the voltage regulator that's built into the alternator. It's the same device you provided the link to. And, I just looked at Rock Auto, they indeed say they accept Swedish Krona (SEK) and ship there as well. But it sounds like you got it going again, so congrats! /R

Yes the brushes worked.
However i seem to be onto something about the regulator because today i held a multimeter to the powercables running into the car and noticed something disturbing..
At idle the voltage read 13v pretty steadily, however when revving up the engine it quickly climbed to 14v and more. Basically the higher i was revving the higher the voltage, and it was steady at whatever rpm i was on. When i was approaching the "rpm limit" the voltage read almost 15v! This would definetly be a fault of the internal regulator? Thinking back to it the car came with a pretty much dead battery and most likely had that for quite some time, this overcharging would also be a reason for the carbon brushes to wear down faster aswell? The ones i replaced had just 2-3mm left on them.

If you have a draft tube, the oil separator is the part that the draft tube is attached to, on the pushrod galley.

Jack

Yes i "found" it right next to the fuel filter thanks!

The return of the engine oil is performed by the vacuumed pumps discharge hose that is also connected to the engine.

The amount of volume the pump moves is so small it will not affect blow by of your engine.

The alternator is repaired like another alternator once you remove the vacuum pump from the rear. Worn brushes have a symptom of erratic alternator output, Overvoltage, under voltage or overcharge/undercharge is a symptom of a failed regulator. Low output and radio interference is a symptom of a failed rectifier.

Alright thanks this cleared alot up for me.
Do you know if anyone sells these hoses for these alternators? Ive found "similair" new generators with the pump attatched but not found any hoses for sale and i think i read somewhere here that they were hard to find ...
I think i will just order a new alternator for the truck but replacing the hoses will probably be needed since the large one between the alternator and engine block is already leaking a tiny bit.

My friend said that you could just press your own but i need to look up how to do that properly before tearing it all down.

[Boltass]

Also does anyone know where to find the driveshaft seal to the transmission?
Mine is both leaking where the speedometer wire is connected and in the driveshaft seal on the backend of the transmission, its leaking quite badly even and i really need to replace it soon as there is a larger and larger sized oilpool on my parkingspot each day that passes . I have just been sticking to filling up the transmission through the second shifter lever hole but its about time to do something about it.

[francis.hamre]

Also does anyone know where to find the driveshaft seal to the transmission?

I found it on rockauto.com just now (output shaft seal). I don't know if you can get on that website or not but it is a great source of parts for me.

If you can at least get to that website, you can use it to find part numbers, then put that part number into eBay or another website that will ship to you.

[JoeIsuzu]

Mine is both leaking where the speedometer wire is connected and...

Leaking on the transmission, or leaking into the instrument cluster?

Jack

[Boltass]

Also does anyone know where to find the driveshaft seal to the transmission?

I found it on rockauto.com just now (output shaft seal). I don't know if you can get on that website or not but it is a great source of parts for me.

If you can at least get to that website, you can use it to find part numbers, then put that part number into eBay or another website that will ship to you.

Ah alright thanks will order one asap.

Mine is both leaking where the speedometer wire is connected and...

Leaking on the transmission, or leaking into the instrument cluster?

Jack

No on the transmission end, however it was somehow loose now when i checked, or rather hand tightened not vicegrip tightened.
I took some poligrips and tightened it 2-3 turns and now its significantly better. Thanks.

[puttputtinpup]

A good hydraulic can cut the banjo fittings off the old lines and replace the rubber line. They'll have to be sure to get the orientation of the fittings correct before crimping them to the new rubber line. Also, they'll have to cut the old crimp off and braze/silver solder maybe a new flare crimp section onto the old banjo part. Then add the rubber hose and crimp. Use new copper or aluminum washers on either side of the banjo fittings otherwise it'll just leak. 2 different sizes I think. Do NOT overtightened the banjo bolt or you'll snap it off. It's hollow. The shop may have new banjo fittings where you are.

[Boltass]

Also does anyone know where to find the driveshaft seal to the transmission?

I found it on rockauto.com just now (output shaft seal). I don't know if you can get on that website or not but it is a great source of parts for me.

If you can at least get to that website, you can use it to find part numbers, then put that part number into eBay or another website that will ship to you.

Any idea which one it might be?
https://www.rockauto.com/en/catalog/isu ... +seal,8792
They all seem to be diffrent sizes
Would be ashame to have to drain the gearbox to check haha