1993 4x4 rear axle differential vent valve

[SCMoore]

The morning after a 90 mile round trip I found a puddle of differential fluid on my driveway. Upon inspection, it appears that the pressure built up and blew out the ABS sensor on the axle. Not completely but that is obviously where the fluid was coming from. That had recently been replaced. Is it possible that the sensor was not properly seated or is my vent valve or tube clogged? I guess my question is, does the valve that the hose is connected to just unscrew from the axle? It looks like it has a crimped clamp on there so I didn't want to mess with it without asking.
I have a 1993 4x4 XLT. Axle code is 91 if that matters

 

[sgtsandman]

My understanding is that there is no valve. It's just an open nipple on the axle with the hose connected and run up to the bed.

My guess is that the hose is clogged and not allowing rhe axle to breathe. Air goes out when the axle heats up and goes back in as the axle cools.

 

[Curious Hound]

My understanding is that there is no valve. It's just an open nipple on the axle with the hose connected and run up to the bed.

My guess is that the hose is clogged and not allowing rhe axle to breathe. Air goes out when the axle heats up and goes back in as the axle cools.

I agree. First, there is no valve. There should be a little doohickey in the end of the hose to prevent dirt from getting in. But it should allow free airflow in or out. Make sure the hose is clean and open. If necessary, get a length if 14" ID fuel hose from a parts store and replace it.

Second, check to make sure the ABS sensor is properly seated and secured. Any time I've had a clogged breather tube issue, it pushed oil out the axle seals. Not the ABS sensor, which is above the oil level in the differential when sitting on flat, level ground.

 

[CamTheHedgehog]

I agree. First, there is no valve. There should be a little doohickey in the end of the hose to prevent dirt from getting in. But it should allow free airflow in or out. Make sure the hose is clean and open. If necessary, get a length if 14" ID fuel hose from a parts store and replace it.

Second, check to make sure the ABS sensor is properly seated and secured. Any time I've had a clogged breather tube issue, it pushed oil out the axle seals. Not the ABS sensor, which is above the oil level in the differential when sitting on flat, level ground.

14" fuel hose? What parts store are you going to?

In all seriousness though, this is correct. There's just a little filter doohickey to keep gunk out, but sometimes stuff gets in anyway and clogs it.

 

[Curious Hound]

14" fuel hose? What parts store are you going to?

In all seriousness though, this is correct. There's just a little filter doohickey to keep gunk out, but sometimes stuff gets in anyway and clogs it.

Ha-ha! Sorry I didn't proofread. 1/4" ID fuel hose.

 

[CamTheHedgehog]

Ha-ha! Sorry I didn't proofread. 1/4" ID fuel hose.

I figured that's what you meant- I just found it really funny for no reason.

 

[scotts90ranger]

For the axle vent cheap clear nylon hose works fine as well, there's no pressure and it's oil proof and resistant enough, I've been running that stuff for years... I think I used 5/16" or 3/8" though...

If oil is leaking out of the ABS sensor chances are the O ring on it is bad, being right at the tone ring means oil is flinging at it constantly.

 

[SCMoore]

Thanks for all of the input. Sorry for the delay in getting back with results. Life got in the way and I was only able to inpsect the vent this weekend. The hose and vent are both clear. I have to assume the ABS sensor was not properly seated and there was enough pressure built up to blow out the seal. I suppose time will tell. This truck isn't typically used for longer trips than a 10-20 miles. I appreciate the help.