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Crankcase Vent Bypass mod

9.1K views 9 replies 8 participants last post by  Garbage_Mechanic  
#1 ·
I was going through some ads on eBay and saw this mod. Will this work on our trucks or is it just for 99-03's?
 
#2 ·
mainly for the 99-03 because they are intercooled and it keeps all the oil out of the intercooler. ive seen people do them on the OBS trucks but dont really know exactly why.
 
#3 ·
mostly for when an intercooler is added.
 
#4 ·
i did it and would do it again in a heartbeat. that is some seriously HOT air and oil mist coming out the crankcase, so besides keeping the air cooler it keeps the airway oil free and when you are pushing alot of boost you want the boots to be as oil free as they can or they slide right off /ubbthreads/images/graemlins/frown.gif
 
#5 ·
What the best way of going about this mod? I have seen some really involved setups like running it into the exhaust etc (not really what im looking for)...I'll be putting my intercooler on here in about a week or so and I would to do the vent mod at the same time....

Thanks,
Casey
 
#6 ·
I took my Breather box off the V/C and flipped it 180 degrees so the tube faces the rear, I then cut a 4 inch piece of rubber tube and clamped it on the Breather Box. After that I put a 90 degree elbow on the end of rubber tube and clamped it. So now it should be facing straight down towards the frame. Then just attach another rubber hose to the 90 degree elbow as far down and back as you can go with out any crimps in the tubing because that will cause pressure in the motor and could cause you to blow out an oil seal or O-ring on the turbo.
Since then I took that leaky POS Breather box off the V/C and welded a small 90 degree tube to the V/C it's self and welded the left hole shut because those O-Rings never seal right after they swell up. Be careful if you do this because even though I was being careful I warped the crap out of the V/C from the heat and cooling effect, and it took about 2 hours to straighten it back out. Nothing worse than a smiley face shaped Valve cover...
JIM
P.S. At the track on Sunday Tech would not let me run until I put the end of the tube into something to catch any oil that might come out of the tube, so I had to grab a plastic water bottle, cut a bunch of holes in the upper half and duct tape the crap out of it to the sway bar to hold it. It was a hokie but it was good enough to let me run…
 
#7 ·
like he said rotate the vent box 180 deg
I picked up 15 ft of 3/4 heater hose and a heater hose splice.
roughted it over the break booster. down along the frame and out the back.

Cratos
 
#8 ·
Jim when you did that with the water bottle how much oil was in it when you were done? wondering how much oil you actually lose by doing this mod. thanks
 
#10 ·
I did this because 1 it was free, 2 I wanted to play with it a little before I intercooled it, and 3 I was tired of oil coming out of everthing on the turbo y pipe. I did it a different way just to experiment, I wasn't sure how much oil and vapor would come out or how much it would bother. I just disconnected the existing crankcase vent hose ebow from the cast aluminium intake part. Capped the hole. DID NOT rotate the breater on the valve cover. Coupled a piece of heater hose (should be oil resistant, but this was an experiment) to then end of the little factory 90. The natural route for the hose was to end up behind the front bumper. The wife (her truck) never noticed a difference in odor, but the top of the engine stays clean now, and there has been no oil come out of the end of the hose, and no problems at all. This is a 190,000 mile motor. So next time I have something to do in this area I will make it permanant.