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CDR valve?

So if I understand this correctly it only is designed to be open at idle or at low enough throttle positions that the turbo inlet vacuum allows the spring to push it open allowing it to flow? Under heavy throttle load it should be shut correct?
 
there is a pinhole on the closed side,sometimes it is plugged,rendering it useless.
they are easy to test.

Take the CDR off the engine
1) hold the valve cover tube closed
2) suck hard on the turbo tube,you should feel the diaphram close.If not,the Thing is toast(crack or hole in the diaphram)
3) put a finger on the pinhole,keep it there.
4) release both tube openings

if the diaprham holds in closed position with the pinhole plugged and opens after pinhole is open ,the thing works just fine.


GW,you may have to much blow by on that old boat,even a new CDR cant handle that,look in my sig for solutions. The 95 version is the better one,cheaper too.

My truck is a 98, so I assume it has the "newer" version already?

Entirely possible my 406 000 km engine has too much blow by to effeciently handle.

As to your sig, are you refering to the provent, or the 2 bolt block?

:hihi:
 
there is a pinhole on the closed side,sometimes it is plugged,rendering it useless.
they are easy to test.

Take the CDR off the engine
1) hold the valve cover tube closed
2) suck hard on the turbo tube,you should feel the diaphram close.If not,the Thing is toast(crack or hole in the diaphram)
3) put a finger on the pinhole,keep it there.
4) release both tube openings

if the diaprham holds in closed position with the pinhole plugged and opens after pinhole is open ,the thing works just fine.


GW,you may have to much blow by on that old boat,even a new CDR cant handle that,look in my sig for solutions. The 95 version is the better one,cheaper too.

Did your CDR have a satisfied look on it when you were done ??
:rofl:
GW,
I changed mine(without giving it a blow job :D ) and I noticed ALOT less oil in the intake. GMCTD did a very long write on the CDR, it's function and his homemade manometer(which IMHO was way too much work to test something that cost 37$)
 
I tend to agree with all the work to test something that cost is only $37 bucs, however think about from this angle...most of the replacement parts IME are junk so it might be worth it to test it early & often.

Kinda like voting here in Ill...early & often lol
 
My truck is a 98, so I assume it has the "newer" version already?

Entirely possible my 406 000 km engine has too much blow by to effeciently handle.

As to your sig, are you refering to the provent, or the 2 bolt block?

:hihi:
actually i was referring to the "road vent" on the 95 and yes the provent as well,
but i have the nagging feeling you're pulling my leg on the..' block';)
 
Did your CDR have a satisfied look on it when you were done ??
:rofl:
GW,
I changed mine(without giving it a blow job :D ) and I noticed ALOT less oil in the intake. GMCTD did a very long write on the CDR, it's function and his homemade manometer(which IMHO was way too much work to test something that cost 37$)
You got a twisted mind ACE,prob from sniffing to much fuel in your job,go seek help.:hihi:
 
... GMCTD did a very long write on the CDR, it's function and his homemade manometer(which IMHO was way too much work to test something that cost 37$)

Wouldn't happen to have a link or remember which forum it was posted on would you?

*EDIT* nvmd, found it :http://www.dieselplace.com/forum/showthread.php?t=11637 (link to another site posted for my own reference, hope that's ok)

... i have the nagging feeling you're pulling my leg on the..' block';)

Nope, not at all...

:hihi:
 
Last edited:
The search doesnt come with any of even my old posts where I quoted gmctds write up. Something not working with old threads on the searching. It was nothing better than the info you have here.
 
I tend to agree with all the work to test something that cost is only $37 bucs, however think about from this angle...most of the replacement parts IME are junk so it might be worth it to test it early & often.

Kinda like voting here in Ill...early & often lol


You need to change your location Crankme69. so it reads location Planet Blogo.

Mark
 
Bison, I just picked up a 95 pickup with a boat load of miles on it. It has a fair amount of vapors coming out of the oil filler tube when I remove the cap. Do you suggest taking off the CDR and running a line back to the oil filler tube? Or to the atmosphere? Thanks.
 
The oil fill and valve cover are the same in this respect, connecting them won't do anything. You can still let it vent into the air intake through the CDR, nothing wrong with that or let it vent
 
Sounds good Buddy, See I have a good flow of vaper coming out the oil fill tube. I wonder if I just take out the CDR valve and let it vent to the atmosphere? I just don't want too much pressure building up causing oil leaks. Or doing any other harm to the engine. Or BK95 mentioned putting in a new CDR but I am not sure the CDR would work right if there is too much pressure going to it.
 
Sounds good Buddy, See I have a good flow of vaper coming out the oil fill tube. I wonder if I just take out the CDR valve and let it vent to the atmosphere? I just don't want too much pressure building up causing oil leaks. Or doing any other harm to the engine. Or BK95 mentioned putting in a new CDR but I am not sure the CDR would work right if there is too much pressure going to it.

This is a good way to make your high blowby truck look like it is on fire from all the smoke coming out of the road draft tube after running on the freeway and stopping. Might as well get your MPG cash from the crankcase oil...
 
You might suck some oil with the blowby but it still isnt going to hurt anything to let it into the intake through the CDR, as long as the CDR does close under high boost. A lot of us have oily intakes inside because of this, but the truck will burn it fine.
 
If the oil fill tube is steaming on top of the turbo still being hooked to the CDR,then there is still positive crank case pressure.It could be that there is more blowby than the turbo can remove or the mess filter in the valve cover is plugged up with gook.

Like buddy said,you can vent the CDR to the world,no need to take it off( just make sure its not restricted),just hook a length of hose to the turbo tube and route it below the engine,and plug the inlet elbow.

Added benefit is that the oil stays where it belongs.

See if it makes the diff,If it still steames from the fill tube i suspect the V cover is plugged,or the rings are gone.

Do comp test
 
My case I pulled the engine out as it was time due to blowby and oil leaks. CDR working and still smoke from dipstick and oil fill. The intake gasket was leaking and would puddle oil on the manifold.

The can is big to work with the pressures involved. But, that stiff spring will be flattened by air filter restriction and close the CDR valve. After all 4 PSI will crush a metal gas can. The slight pressure difference from the air filter is enough to collapse the spring. I don't know that the CDR ever closes 100% as there will always be some blowby.
 
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