Now that I am almost done with my birf job, I really want to make sure that my diff breathers are venting properly. How can I do that? How are they supposed to work?
Jared
Jared
Diff Breather check? (1 Viewer)
- Thread starter sjpitts
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one way is to drain fluid with the fill port closed (crack open the fill first just in cast it is suck then close ti again) if the fluid comes out "goes glug glug glug...." as it alternately flows oil out then air back in then the breather still has the OEM evil little flapper or is otherwise plugged, if it pours out smoothly in a steady stream then the breather is breathing.
also if you hear air rushing in when you open the fiil port then it still has the flappers.
also if you hear air rushing in when you open the fiil port then it still has the flappers.
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The best way IMHO is to get about 12' of 1/4" fuel line and a couple of little plastic fuel filters and disconnect the factory lines and run new lines to the master cylinder area in the front and into the jack cavity near the fuel filler in the rear, capping both with the filters. 
- Thread starter
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Thanks Kevin, but that would be a way to replace your vent line. I just wanted to know how to find out if that little vent cap thingy was working, or if the system was clogged.
Isn't there a way? Or are you really better off just replacing the thing?
Jared
PS-- Kevin--- do you have a picture showing where and how you ended your new vent lines?
Isn't there a way? Or are you really better off just replacing the thing?
Jared
PS-- Kevin--- do you have a picture showing where and how you ended your new vent lines?
NorCalDoug
problems solved daily...
Jared,
I'd just extend them like Kevin stated.
I have my front and rear breather lines connected with a "T" to a common line that terminates in my engine compartment. I capped the top with an inexpensive fuel filter.
It's easy to do and you'll essentially be killing two birds with one stone -- you'll have extended diff breather lines and you'll know that your new lines will be vented properly.
I'd just extend them like Kevin stated.
I have my front and rear breather lines connected with a "T" to a common line that terminates in my engine compartment. I capped the top with an inexpensive fuel filter.
It's easy to do and you'll essentially be killing two birds with one stone -- you'll have extended diff breather lines and you'll know that your new lines will be vented properly.
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sjpitts said:
Nope, it was way simple, just ran them up as high as possible, held them in place with zip-ties and capped them with fuel filters.
"Here is a different way to vent your diff"
https://forum.ih8mud.com/showthread.php?t=46604
Here are some pics from a very clean install by cdan.
Derek
https://forum.ih8mud.com/showthread.php?t=46604
Here are some pics from a very clean install by cdan.
Derek
- Thread starter
- #9
It looks to me like CDAN is still using the stock vent-cap on his extended breather.
OTOH, Kevin says he just used filter.
Which is the better approach? And again, does any body know how those vent caps are supposed to work, and how you can confirm they are working?????
Jared
OTOH, Kevin says he just used filter.
Which is the better approach? And again, does any body know how those vent caps are supposed to work, and how you can confirm they are working?????
Jared
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sjpitts said:
The stock breather is a one way valve, allows air out but not in, at first glance this looks good, you don't want to pull dirt/muck/water into the diff right? So your cruising and the diffs are up to operating temp, then submerge them. The water rapidly cools the diff causing a vacuum in the housing, the stock breather holds the vacuum so any little leak in the housing pulls in water, also blamed for pulling grease from the birf housing into the gear oil. With a free flowing filtered breather the diff is always at the same pressure as the surrounding air. Some people who play in water often use a small compressor to keep the diff housings at a slight positive pressure, driving out water when submerged.
Don't think there is a "right" way, when I installed the L shocks the stock breather lines were too short. So rather than spending anytime on the subpar stock system, I just replaced it, it was cheap, quick, easy and works, what's not to like?
Here's a link explaining the how to's and what for's:
http://www.landcruisin.com/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=8;t=000896
You can skip down to Beowulf's post.
Should probably be in the FAQ's.
Rookie2
http://www.landcruisin.com/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=8;t=000896
You can skip down to Beowulf's post.
Should probably be in the FAQ's.
Rookie2
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- #12
Tools R Us said:The stock breather is a one way valve, allows air out but not in, at first glance this looks good, you don't want to pull dirt/muck/water into the diff right? So your cruising and the diffs are up to operating temp, then submerge them. The water rapidly cools the diff causing a vacuum in the housing, the stock breather holds the vacuum so any little leak in the housing pulls in water, also blamed for pulling grease from the birf housing into the gear oil. With a free flowing filtered breather the diff is always at the same pressure as the surrounding air. Some people who play in water often use a small compressor to keep the diff housings at a slight positive pressure, driving out water when submerged.
Don't think there is a "right" way, when I installed the L shocks the stock breather lines were too short. So rather than spending anytime on the subpar stock system, I just replaced it, it was cheap, quick, easy and works, what's not to like?
Ok, now I am convinced. That is a good explanation.
Thanks Kevin
Jared
/you still suck
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That's a hard way to do it. I did each end separately, the rear is routed from the diff along the fuel filler pipe to the left rear quarter, in along side the sunroof drain and up to the fuel cap area.
Going into the quarter.
At the fuel filler.
The front termination.
Going into the quarter.
At the fuel filler.
The front termination.
in my 80 series it looks like I have diff fluid splattering out of my breather, need to investigate this issue and probably will end up combing the front and rear with a T and route the line up into engine compartment. Not sure why it’s splattering bec from what I read I other posts people seem to say the issue is with forming a vacuum not over pressuring
ppc
M Go Blue
Contaminated gear oil can causing foaming and be pushed out the breather. The contamination can be water or grease being sucked into the axle housing from the birfield.
thanks for the reply ppc, yeah its about time i did a knuckle rebuild seeing as my knuckles are leaking some which i assume is because of a bad axel seal (not leaking enough to be dripping on the drive way yet though). So your explanation regarding contaminated gear oil seems very plausible in my case.
also i just realized my front breather can get stuck in the up position so water very well could make its way in aswell !
