TheSamba.com :: View topic - UPDATED: Need help help finding a NOS part.

Mon Jun 01, 2009 8:23 am

when in doubt, I use simple green. I never know what seals and such are actually made of, and solvents tend to disolve everything i don't want them to.

also, is anyone familiar with the PCV setup for a1700 smog pump engine?

Tue Jun 02, 2009 8:52 am

I have found a place in California that can make these diaphrams for the 1975 - 1978 FI bus. Don't have a price yet but the mold guesstimate is reasonable and the diaphram is too. Probably will be like the original in silicone rubber. The question will be how many of these to make. They will probably be under $10 each shipped for the diaphram and will come with instructions how to get the PCV valve apart and how to clean and replace. Please send me a PM is you want to be on the list of people who buy them. I am guessing there are about 150 of us who need them but if we don't get that many who need them could be as much as $25 each (based on 50 made and sold)

Tue Jun 02, 2009 11:29 am

Yep, it sounds like thye are making a temporray mold like I make for doing small parts. Very fine detail.....and could make a few hundred to maybe a thousand vacuum cast parts before it craps out.
I would volunteer to mold these.....but I have lot on my plate right now. If not enough people step up...I can do it.

Bear in mind...that silicone casting compounds have come light years since these diaphrams have been made originally. You canget newere silicones that have 600+ heat rangew and are almost totally checmical proof. The real question will be what hardness and level of flexibility will work. Ray

Tue Jun 02, 2009 11:37 am

fusername wrote: when in doubt, I use simple green. I never know what seals and such are actually made of, and solvents tend to disolve everything i don't want them to.

also, is anyone familiar with the PCV setup for a1700 smog pump engine?

Uh...just so you know....Simple Green...aint that simple and it aint that green. Its a decent degreaser....but its main two ingredients are 2-butoxyethanol and Butyl Cellosolve. You should not breath either and highly limit contact with skin. Also....personally I would be very careful with using it on rubber and plastics. Ray

Tue Jun 02, 2009 12:01 pm

I suppose a sample would be make and tested for QC purposes?

Wed Jun 03, 2009 12:08 pm

Is there an easy way to test the breather valve without disassembling it or having a vacuum tester? Every time I remove my S-boot there is a decent amount of oil in the bottom of it, and I'm pretty sure it's coming from the breather tube--is this a sign that the diaphram is bad?

Thanks for doing all this legwork SGKent.

Wed Jun 03, 2009 5:43 pm

evanwilliams4u wrote: Is there an easy way to test the breather valve without disassembling it or having a vacuum tester? Every time I remove my S-boot there is a decent amount of oil in the bottom of it, and I'm pretty sure it's coming from the breather tube--is this a sign that the diaphram is bad?

Thanks for doing all this legwork SGKent.

no, could be your rings are worn so you have lots of blowby..which includes lots of misty oily gas which condenses in the S boot.

do a leak down test to see what going on..

Wed Jun 10, 2009 12:21 pm

You can take it off and use a piece of hose that attaches to the end that goes to the air intake. Plug the other end with your finger and suck on it to see if it holds vacuum. I also blow a little pressure the other way too,but not much and it should hold pressure as well. Sometimes the diaphragm has a crack that is more susceptible to opening when bending the other way. I disassembled mine and made a spring clip that holds it together. Now I can take it apart for maintenance. It was actually full of gunk on the inside so the flow through it was restricted as well. I put it back together with some RTV (repaired the diaphragm too) and then put a spring clip on to keep it hel together. It works like a new one now....now to see if my MPG improves as well.

Wed Jun 10, 2009 3:34 pm

I was doing some work on a 78 Datsun 280Z yesterday and noticed that it uses a flow through PCV valve system (280's use L-jet in case you are wondering), I'm hoping to get my hands on the valve that screws into the plenum that the breather connects to and whatever is in the line from the rocker cover to the S boot they call a "flame arrestor" soon for some research.

Sat Jul 10, 2010 6:30 pm

Back from the dead!

Was any final resolution made on this?

I was actually searching for the I.D. of the Sboot when I stumbled on to this thread.

It seems that there are an increasing number of NLA parts that are going to drive the FI Bus right out of smog states. In NJ, everything gets smogged, with no cut off date. I don't know about the visual inspection, however. (My 72 SB is registered historic, the only way you get off the emissions merry-go-round.)

M

Mon Jul 12, 2010 6:08 am

This thread has opened my eyes to a whole new part of the engine to worry about! :shock: :D

Now, how does one go about properly testing the PCV valve? And what maintenance can be done without dismantling and damaging it?

Tue Jul 13, 2010 9:39 am

Wow. Tripped over this in a search and didn't realize that little bugger was made of unobtanium. My engine was or originally a 2.0L F.I. and I HAD one but had no clue what it did other then help vent the crank case somehow. When I got the bus it had been converted to single carb and there was a hose coming off the plastic piece and just running over to the spare battery tray. (Don't yell at me here... I was new!!) When I got a new Weber single carb I hooked it up to the back of the air cleaner and assumed it was working. :oops:

So a few months ago I pulled the engine and once it was safely on the ground I pushed the bus over it and the lip/head of the plastic thing got caught under the bumper and SNAP! :shock: It didn't phase me at the time and I just assumed I could get another one... and did up until 10 minutes ago. Woops.

Last weekend I was picking pieces off a '74 1800 duel carb and remembered I needed this piece but mine being originally a Fuel Injected and the 1800 being carbed obviously it wasn't there. So I took the metal vent box off and just assumed I could swap that on. Now that I'm putting on duel carbs... WHERE is this hose really supposed to go?

Here's a pic I took of the 1800 engine before I took the vent box off. The hose is missing though: (Upper right hand corner)

Tue Jul 13, 2010 11:25 am

thewalrus wrote: WHERE is this hose really supposed to go?
To the nipple on the air filter neck (hose goes under and around the front).

Sun Jul 25, 2010 9:48 pm

If you have dual carbs and no factory airbox, where shoud the hose from the crankcase breather go? Should it be connected to anything or just vented out underneath the engine somewhere?

Fri Aug 27, 2010 10:36 pm

Hey SGKent,

Any updates on the replacement diaphragms????

Sat Jan 22, 2011 11:35 pm

Bobbie found me 2 NOS last last year but nothing on the diaphragms. Don't have the money to make new ones.

Tue Aug 09, 2011 5:33 pm

Any progress on this?

Tue Apr 24, 2012 2:08 pm

the cheapest I have found someone to make them is out of the price range most of you would pay. I bumped this because someone contacted me re finding a diaphragm or whole new valve. The last new ones I found were in Europe and it was Bobbie who found them, however he no longer frequents here as he lost lots of money selling NOS items due to problems delivering.

Tue Apr 24, 2012 3:13 pm

I spent a little time pestering the parts guy at the local VW dealership and came home with a similar valve for a 2003 1.9L TDI Jetta/Beetle. It works on the exact same principles but its flow rate is a bit higher. A very important factor is the valve is in the proper orientation, meaning it is designed to go into the valve cover and not the intake boot like the Audi part I've seen.

Only issue so far is a bit of a high idle when completely warmed up. Seems I have some decent blow-by and this valve flows more. I am looking into restricting it to the same size hole that is molded into the upper section of the original valve.

Tue Apr 24, 2012 4:52 pm

Chris_914 wrote: I am looking into restricting it to the same size hole that is molded into the upper section of the original valve.

thats easy enough. find a piece of pvc (or what have you) and slide it inside of the valve to whatever dimention you want to choke it down to