Type 4 Breather Box Valve ?? Re-visited

[ser123ser]

[ser123ser]

Another work in progress nearly complete now is the breather box on my Type IV motor.

I have a type IV motor 1975, built at 2 liters, using the stock FI. I have a cheapo EMPI exhaust on it.

I do want to post this because I found a solution that was not expensive, easy to retrofit and can be taken to the next level for a final outcome.

Here are the links to the 2 post's on this site in regards to the subject matter where as a lot of replies went back and forth.

http://www.thesamba.com/vw/forum/viewtopic.php?t=251133&postdays=0&postorder=asc&start=0

http://www.thesamba.com/vw/forum/viewtopic.php?t=295812&postdays=0&postorder=asc&start=0

There were some others. Several regular posters SG Kent and Ray Greenwood talked about making replacement parts for the existing units and a ton of discussion on how this thing works. Some discussions were to convert from factory crank case pressure regulator to a PCV valve of some sort etc. etc. I also ran into posts and replies about just leaving the oil level low on the stick and the blow by is reduced. Not completely but less never the same. This does not work for me as this motor is like a 3 quart motor in the case and leaving out a ½ quart or more is a disaster waiting to happen.

I kind of discovered that a 2002-04 Audi A4 uses the same pressure regulator just a little different looking than ours in mounting. Here is the supplier.


http://www.ecstuning.com/Audi-B6_A4-FWD1.8T/Engine/Emission/PCV/ES7858/

I bought it and put it on my motor using the old "blown" pressure valve as a 90 deg elbow breather tube. See the photos attached. Also use some sealer on the little vent hole on the old pressure regulator that was a ambient pressure vent hole for the blown out diaphragm that is in the sealed case of your old pressure regulator. This completely seals the old pressure regulator and makes it an elbow for your new regulator.

Fast and Easy. Like me

When I got my bus and tore down the blown motor, aside from the usual evidence of low oil, hot oil, overheated parts there was a lot of oil from blow by out of the crank case in the "s" boot, plenum, intake tubes, valves, carbonized pistons etc.

As I bench tested every component of my FI (many times over and over) to understand how this is going to work, when I got to the pressure regulator I had a feeling this thing is not right but not knowing what I know now I put it on the motor and kept going.

I have sorted out the leaking front/rear main seal problem (3 times pulled the motor) and I have no drips. I was still consuming oil from top line fill to the lower level. As I did the motor pull three times I noticed oil in the "s" boot, throttle valve, hoses coming out of the breather box. hmmmmm.... I did some homework (read the samba links about 20 times) to figure this little thing out and then went out to find a new one. They don't exist any more. Somewhere I stumbled on a search for pressure valves that they are on Audi's and VW passats etc. Went to a junk yard and found these things but they were in bad shape.

Found this site ECS Tuning) and bought one. Trippy, it does not completely stop flow of pressure but it stops a lot of it. More than by half (my guess with it in my mouth)

The site did take two weeks to ship it as this is one of these drop ship joints on the web selling stuff. It eventually it got here.

I found an Audi forum that explains the pressure regulator the best I have seen. Here is the link;

http://forums.audiworld.com/showthread.php?t=2802385&highlight=pcv+valve

Here is the description that I am referring to;

"For the part you have referenced, here is a description from "diagnosticator" over on AZ. Guy knows what he is talking about:

"The diaphragm is crimped around the edge and forms a chamber between the top of the diaphragm and the top cover. The bottom side of the diaphragm forms the top of the lower chamber that has the center inlet port and the outlet ports. The top chamber is vented to the ambient air pressure. When the pressure at the outlet port is lower than the crankcase pressure relative to the ambient pressure, the diaphragm is pulled downward and partially blocks the inlet port inside the valve, reducing the volume of crankcase blow by gasses that are pulled out of the crankcase that flow into the tip. When the CC pressure is higher, the diagram moves up away from the inlet port, increasing the flow area inside the PRV and vents more blow by to the TIP. The distance of the bottom side of the diaphragm from the inside end of the inlet port, and the resulting flow area of the blow by gasses in the valve, is determined by a balance between the crankcase blow by volume and pressure, the outside ambient air pressure, and the pressure in the TIP.

When the valve gets old, the diaphragm gets stiff and will not respond to the low pressure differentials that operate the valve normally, effecting crankcase ventilation control accuracy." "


I have 300 miles so far on this pressure regulator and I am happy to report no more oil in the hose from the tower to the "s" boot. It is dry as a bone. My hot idle became more consistent and stable since I put this new regulator on. So I been able to drop the idle screw on the throttle valve back a 1/4 turn. I have a hot consistent idle at 850 rpm. Very sweet….My biggest deal was the oil suck into the intakes. This is just carbonization waiting to happen.

I have to think that a vast majority of busses have blown pressure regulators. Now you have a 50 dollar fix. Also this part comes off a 1.8L, 4 cylinder motor so the pressure setting for blow off has got to be nearly similar.

This is a fast and easy fix for most any one at this point. If you want to get a little more fancy, go to the plastic store in your area and get some high temp plastic sheet about 1/4 thick and pattern the bottom of your original pressure regulator mounting to the tower box. (it will look kind of like a oil filler tube gasket) make your center hole the size of the new pressure regulator (eng suck side) JB weld it to your new mount plate and put a o-ring on the bottom and bolt it on. Not as fast and easy but....nearly stock looking for you tinkerers.

Steve
Perris CA.
Outstanding in my field (with a tube of bath tub sealer in my hand)

https://www.thesamba.com/vw/gallery/pix/882764.jpg

https://www.thesamba.com/vw/gallery/pix/882765.jpg

[1975 Kombi]

What is the OD. of the inlet and outlet and are they still available from VW.
_________________
Brett

“He’s decieving you boy! Reach into his pocket and take what he’s got.” Mr. Crabbs.

75 Westy auto
03 Jetta TDI
71 SB
74 Westy
2011 Touareg TDI
2001 NB TDI
Licensed pilot (single engine land VFR)
--
Rust In Pieces: 72 Bug, 73 Bug, 81 Rabbit LS D 2D, 83 Rabbit D 2D, 84 Jetta TD GL, 85 Jetta D, 68 Z28 RS 302, 91 Passat 16v

[ser123ser]

1975 kombi, its the same as the original output side of the pressure regulator. When I went looking in Junk yards I found these pressure regulators and noticed they were the same in hole sizes as the original. But they were all broken or "suck thru's" None of them worked. So I manned up and bought one as I noted.

I did not buy the cloth covered hose that cost's 20 bucks from the vw joints for the breather box connection to the "s" boot. That is a rip off.

The hose in the picture is 3/4" vent hose that I have been using for about a year now clamped tight.

I cut into the existing hose as you see in the pictures and stuffed this thing into it and added 2 clamps. Pretty much a perfect fit.

fast and easy

Steve
Perris CA
outstanding in my field.

[SGKent]

I did a test of a similar valve and found that it differed a little in how it behaved but it was close. As long as the valve is designed to hold the crankcase pressure to appx ambient it would work. If someone wants to make a little side business, make an aluminum or plastic mount that bolts on like the original and has a hole with a rubber grommet on it that will fit one of these. You would have essentially the same as the bus unit AS LONG AS it closes about the same vacuum. I gave up on replacement diaphragms because the cost was too much for the number of people who wanted one. (eventually almost all will need one who have L-jet) but found a workable solution.

_________________
"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[1975 Kombi]

[john_wade63]

I found that breather on Amazon for $10. It's not genuine VW, but I'll give it a try (I bought 2 of them, so I have a spare).
http://www.amazon.com/gp/product/B003NRIOH8/ref=oh_o01_s00_i00_details
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1979 Transporter

[1975 Kombi]

[Whitley]

I got one of the Audi breather and used a 1/2" cast iron floor flange (the OD of the 1/2" pipe is 3/4"- same as the breather) then cut the flange like the original mount for the two bolts on top of the tin box. I then ground the flange smooth, made a cork gasket, and assembled. The Audi breather is connected by a 1-1/2" section of 3/4 heater hose. Two hose clamps and that was it. If the Audi breather operates the same, this is a relatively cheap fix to a common hidden problem. I found the breather online for $40 http://www.dbcperformance.com/06A129101D_p/06a129101d.htm and spent $4 on the rest of the parts.
_________________
Third and Sixth owner of a 76 Westy

What I do- www.mwhitley.com

Dig Americana Music? www.markwhitleyband.com

[Hoody]

I firmly believe this is a crucial part of the l-jet set up. Anyone who has taken one of these apart knows how paper thin the original diaphragm is. A lot of folks think their oil tower seal is leaking when in fact their pcv valve is shot. Nice work on the work around. I bet GEEBEE could die cut a silicone disc or mold one to the exact specs. Rebuilding the original pcv valve with the correct diaphragm would be simple.

[timo78]

I happened upon this in a search regarding breather tests.
What if any test is there of the breather? Is it take apart for a visual check?
Thanks
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> 78Grµn Westfalia `Donkey`
.
It may be bigger than you and it may be bigger than me, but it’s not bigger than you AND me; can you dig it?

[Wildthings]

Do Bay and air cooled Vanagon breathers work the same? I know that WBXer breathers maintain different pressure in the crankcase then do Bay breathers, and that WBXer engines seem to work just fine with a failed breather.

Just reading what was posted a while back, it makes no sense at all.

[SGKent]

[Wildthings]

Your explanation is correct, it is the relative pressure between the case and the atmosphere that counts not the case and the S boot as mentioned in the erroneous quote. I can never remember though whether the Bay relief valve maintains a slight positive or negative pressure in the crankcase, a slight vacuum I believe but am not sure. What I do remember is that it is opposite of what the WBXer pressure relief does. I would like to know just for grins what kind of pressure the AC Vanagon's relief valve maintains, the same as a Bay or the same as later Vanagons. For myself with the open breather from an early carbed engine this is just one more part I don't have to worry about.

When people are trying to fit some other relief valve to a Bay engine it would be good if the valve maintained the same pressure as the original. As you said an improperly functioning valve can have the effect of being a vacuum leak so the valve with the correct characteristics would be a plus.

[timo78]

Read some other posts, on TS and STF that gave insight into a test. It's very simple. Blowing through the vent hole in the cap, should produce no escape. And when plugging either outlet end and blowing through the other end no air should escape. This should mean the valve is at least not breached, but there may be flow obstructions.
Removed the breather box valve and hose. There was some "mayonnaise" that I wasn't expecting. Cleaned it out with some engine degreaser and then a few hot water bath and rinsings. Dried and tested. Plugging one end and blowing into the other end, and the tiny vent hole I did not notice any leaks. Upon re-install I notice now when I release the pedal that I don't have the slight hesitation when re-throttling. I'll see if I see if this improves upon blown oil around the breather box and various seals too. While minimal, that's the reason I started to look at the breather box being clogged or not operating effectively.
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> 78Grµn Westfalia `Donkey`
.
It may be bigger than you and it may be bigger than me, but it’s not bigger than you AND me; can you dig it?

[SGKent]

[Whitley]

This little part has been bugging me, and I'm retracting my previous post about the simple swap in of the Audi PCV valve.

I dug my stock breather back out and decided to take it apart and found a busted diaphragm. Seeing that the og diaphragm is controlled by the little spring, and that its only job is to close off the small tube under the center of it, I decided to replace it with some .025" diaphragm rubber I had from another job.

It also became clear that the only job of the little hole was to let the diaphragm release when the vacuum on it lessened.

I took the bus on a long drive the other afternoon, with a lot of hills where I the engine rpms were up, but my foot was not on the pedal, and found when I returned home, a great deal of blow by through the Audi set-up. I'm only guessing, but maybe that is the time when the stock breather really does its thing and serves to equalize the internal pressure when the throttle is closed, but the rpms are high.
_________________
Third and Sixth owner of a 76 Westy

What I do- www.mwhitley.com

Dig Americana Music? www.markwhitleyband.com

[SGKent]

[Wildthings]

[bummerbus]

Yes the spring is on the same side in the Audi valve it's bigger as well
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‘75 FI-1800cc.