The only time the cdr us going to do jack if if you have a horribly clogged air filter.....
You need at least 1-2 psi of vacuum in the intake to get that thing to close..... And if you've got that kind of vacuum you've got other problems.
Cdr has no function other than to keep your engine from sucking all the oil up in the event the intake cliffs completely.
No connection to oil consumption - none.
Not at all true.
The CDR functions in a much more complex manner than just by vacuum alone. It also operates by the pressure being built up inside the crankcase by the blowby pressure. Have you ever noticed how small the outlet is for teh CDR? Much too small for a true functional RDT for a diesel engine this size ( heck the 216 gas engine in my 41 chevy has a RDT over TWICE that diameter... are we getting the picture here?) pressure alone is not enough to remove blowby gasses properly, it requires a balances level of crankcase scavanging via vacuum to pull the gasses out. The problem arises when rpms get too high or crankcase pressure gets too high, , if you just have a straight tube, then the vacuum will get too high along with the pressure and a siphoning effect will setup and your intake will begine to suck the oil straight out of your engine. If its bad enough you can wind up with a runaway ( ask the nice folks at VW about this )
Along comes teh CDR, notice it is called a Crankcase REGULATOR not a crankcase open closer. When the pressure/ vacuum situation approaches that critical point, the diaphram begins to FLUTTER to break the vacuum , in turn stopping the siphoning effect and keeping your oil where it belongs . THis can happen any time, either at high rpms or when stuffing your foot into it. Worn or sticky rings can give it a real work out.
If the CDR were to actually close off , you would quickly blow out all of your major seals ireparably .
If it fails to pull in or has a hole in it, then it is incapable of breaking teh vacuum and you will continue to suck oil in, plain and simple.
By the manual they are supposed to be cleaned at each oil change, most have never been touched by the time second owners get them and are in horrible shape.
By rights, you should be able to get at least 100=150k out of one, they use the same setup on manu Cat engines and they hold up quite well, but you need to take care of them. Sludge will kill them quickly, if not cleaned it will eat teh diaphram up, broken down oil gets nasty and eats things up _
