Mk1 Modified engine breather.

[dalderton]

I am looking for information,preferably photos of the modified engine breather setup introduced in 1979 by VW to hopefully stop the air cleaner sucking oil into the body of the cleaner and the element. I have a 1980 GLD and it suffers from this problem.I did not realise that there was a mod until I looked at a site last night where it was mentioned.I can fabricate the bits if necessary once I know how it works. Any help would be appreciated .Incidentally I run the car on vegetable oil and it seems very happy on it .Is anyone else using 100% bio in a Mk1. 50c a litre to make it is a most attractive option!!!
Regards Dennis

[gldgti]

hey mate - i dont have a photo but the setup is simple. all you need to do is put a "t" in the rocker cover/airbox breather hose, and a "t" into the hose from the crankcase to the vacuum pump and connect them up with some 18mm rubber hose. thats all there is to it. this allows the pressure to equalise and since its almost always positive towards the crankcase it tends to drain well.

poly-ethylene T fittings will do the job if you dont want to shell out the extra dollars for brass, since it doesnt get that hot.

give it a go - by the way, its a sure sign of ring wear if your filling up with oil in the filter box, even without the extra breather hose, but you should get plenty more km's out of it without too much worry. I sucessfully re-ringed mine (without getting new pistons) and after 100,000km its still not burning oil like it did before.

with regard to biodiesel...

i use B100 in my mk3 and used to use it in my mk1. my dad runs his mk1 on b100 homemade, as well as a merc 240D. the only issues you are likely to have are cold winter morning starts, filter clogging in the first 1000km from cleaning the fuel system, and o-ring degradation on the injector pump, which is an easy fix and no real issue. the benefits far outweigh any small inconveniences IMO.

install a $3 clear housing inline filter from supercheap before your big filter to give save you the hassle of replacing a big filter and you wont have any trouble.

Oh, and ...

Welcome to the forum! happy to have another dieseler!

[Oneofthegreats]

Welcome to the VWW world. Hope you enjoy it here & find some useful info.

I'm not a diesel guru, but if your after a engine breather mod, here's mine.

Run a piece of good quality hose from your rocker cover breather straight into a catch can (or powerade bottle in my case) with a "autobarn special" filter attached to the top.

This allow's your engine to breath without filling up the cabin with engine fumes too!

Also block off where the original rocker cover breather connect's too.

[iain]

I have run my mk 1 on B100 for about 8000k's now. I've replaced the fuel lines under the bonnet with a very expensive (100 bucks or so!) kit I bought online from Greaseworks. I still haven't bothered with the rubber lines at the tank. The return lines were the first to show weeping from the bio. Using a cheap filter as described by gldgti caught stuff for the first 1000 or so k's, I still haven't had to replace the stock filter.

I did have a problem with the injection pump leaking at the throttle shaft. After putting a tank of normal diesel through it this leak worsened. As soon as I went back to bio it stopped almost completely. I put this down to the swelling effect of biodiesel vs the shrinking effect of ULSDiesel.

I buy B100 from a place in Thomastown in Melbourne. $1.10 a litre, cheaper than fossil fuel!

I'd like to see pictures and a description of your veg oil system as I have been considering it myself, the chemicals needed to make bio put me off doing it myself.

I have the breather mod already fitted in my mk1. However, oil still collects in the airbox. I fitted a cam baffle but this seemed to have no effect. I've also experimented with various attempts at a homemade oil/air separator. While one worked quite well it started to pressurise the engine causing oil to escape at the dipstick. As the engine seems to breathe better without I've gone back to the original breather mod, oil residue be damned!

Cheers.

[dalderton]

Thanks for the info and suggestions.I will experiment a little and see what happens.It seems a strange thing to exhaust the vacuum pump into the crankcase which I would think would pressurize it and make the problem worse.I probably is worn rings although it does not use much oil.
As for the bio I have been using it for some time in my Pug 307 HDI (20000km) with no problems other than in winter when the temp gets below about 4degC when I add about 25% diesel which pretty much solves the problem.I also use it in a T3000 Mazda bus (camper) (15000Km)also with no problems other than the above.I have just reaquired the GLD after an absence of 4 years to use as a runabout because I am addicted to 50c a litre fuel.
Iain: If you send me your email address I will send you a few notes I made on making bio and a couple of pics of the gear that I use.
Incidentally it seems that the Mk1 cam cover is better than the standard one for separating the oil from the air at the outlet.
Thanks again all Regards Dennis

[gldgti]

as standard, the vacuum pump is lubricated by crankcase breather air (carrying lots of oil). the later revision system, which is what you are after, is simply a new hose connecting the rocker cover breather to the crankcase/vacuum pump breather hose. that is what i have described above.

ALL mk1 diesel owners take note:

it is a design condition that some oil collects in the bottom of the airbox on the golf mk1 1500 diesel engine. many people do not realise that there is a single 0.5mm hole in the top of each intake pipe in the manifold, (in the bottom of the airbox) that allows some oil to ventury into the inlet passage of the head on each cylinder, and lubricate the inlet valve seats to prevent wear.

as such, fitting an atmosphere breather will likely over time cause your intake vavle seats to wear prematurely, and your valves will not seat properly causing caompression leakage.

it is highly advised that breather rocker cover air is diverted to the airbox to stay within design considerations for the 1500 diesel engine. the later vw revision, adding the extra pipe, does not reduce the small natural amount of oil from entering the airbox, but will aid in preventing air cleaner soakage and possible runaway on well worn engines with high oil consumption and blowby.

[gldgti]

for biodiesel...

the main throttle shaft o-ring failure is a common problem for cars run on b100. if you are clever it is possible to find a replacement o-ring made from VITON which will not degrade in the presence of methyl or ethyl esters (biodiesel) and hence prevent further leaks. alternatively, you may consider replacing the rubber o rings on a more regular basis.

injector return lines are also common to leak. clear, PVC fuel line is a cheap replacement, and synthetic rubber hose works well too.

[dalderton]

GLDGTI Thanks for the explanation of the breather system,I was not aware of the lube part of the equation. Also the info on the pump o rings. I will do your suggested mod on the breather system asap. Hopefully the added lube supplied by the bio will help the valve seats as well.Incidentally I had the head off to replace the head gasket and it had what appears to be the normal small cracks between the seats.The local head man said it was knackered but I peened the cracks and put it back together and all appears to be well.Time will tell.
Do you know if my GLD (12/80)would have been fully imported or locally assembled? The reason I ask is that the body is virtually rust free.
Thanks again for the info Regards Dennis

[jets]

GLDGTI Thanks for the explanation of the breather system,I was not aware of the lube part of the equation. Also the info on the pump o rings. I will do your suggested mod on the breather system asap. Hopefully the added lube supplied by the bio will help the valve seats as well.Incidentally I had the head off to replace the head gasket and it had what appears to be the normal small cracks between the seats.The local head man said it was knackered but I peened the cracks and put it back together and all appears to be well.Time will tell.
Do you know if my GLD (12/80)would have been fully imported or locally assembled? The reason I ask is that the body is virtually rust free.
Thanks again for the info Regards Dennis

All the diesels were fully imported, it was only the first LS petrol versions that were assembled here. I remember something about 7 years warranty against rust perforation in Europe, so in our climate a lot longer. Had a quick look at some old brochures but can't find anything now. Mine has surface rust in a few places but nothing through the panels, even after spending all its life near the beach.The small cracks between the seats is fairly normal & shouldn't affect the running.

[cetane]

Cheap breather mod

Have a look here:

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=115&highlight=breather+diesel

And the replacing of the "O" ring on the throttle spindle will help stop leaking. If as Ayden says you're using bio or canola you'll need to source one made form vitron. From my experience it pays to replace the bush in the governor housing is there is any wear at all.