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My axle vent isnt venting!

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Duane Black

Curbs go brrrppp
567
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5-10 Years
Durham, NC
As the weather got hotter, I noticed a bit more diff fluid escape my vent during track events, like at Sebring for instance, where as I was fine in the spring at VIR, I was fine. The other day, I went to add a pint to be safe. And as I was removing the plug I heard hissing! I removed my vent too and blew through it, then ran some carb cleaner through it to be safe.

The problem is, I've done this before for the same problem, and not very long ago.

So do I just replace the vent? Or is there a high performance option?
 
1,161
2,116
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5-10 Years
SoCal
Just finished installing this kit for similar reasons. I was fighting clearance issues with lowered ride height and 3” OTA pipes burning the vent hose off. This caused the vent hole to plug on the last track outing and took the driver side wheel seal out. Ended up swapping the hose and fittings to low profile AN swivel fitting and AN push locks to get the clearance right. Overall this is a very high quality kit.

https://bobsmachine.com/product/mustang-2005-14-axle-reservoir-kr-style/
 
FWIW I owned one of those canisters and I’m not a fan due to clearance issues. I’d go with one similar to the race cars and we have a detailed thread on a DIY kit but I can’t seem to find it.

It looks like this.

A8E20E74-B499-4DD8-9C50-0DDFCCEF6E68.jpegADAB9063-BE2A-4471-B731-23031FFC6E10.jpeg27027583-96D5-449E-BCE1-78400FAB0B72.jpeg91C7BC21-8B9B-412C-8D24-051C80332222.jpeg81F95AAD-C061-4F43-BF4B-B7AA91D2C905.jpeg
 

Grant 302

basic and well known psychic
Where is your vent? On my GT, I moved it from the Axle tube to the top of the (added) finned aluminum diff cover. Hasn't leaked since.

I think the hissing you heard was from vacuum created after the cool-down. Nothing abnormal, IMO.
 
1,161
2,116
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5-10 Years
SoCal
That race style one is so awesome! Agree with Rick about the Bob's reservoir - too much interference no matter what fittings I used and how I positioned them. Ended up using one of these JLTs which allow for mounting on either side of the pumpkin, venting off the axle or the diff, and you can clock it around to whatever angle works to prevent contact.

https://www.jlttruecoldair.com/jlt-rear-axle-expansion-tank-2005-14-mustang/
Assuming that you were using the vent port on top of the diff cover as well? Im going off the axle tube since the Whiteline watts cover doesn’t have a vent port, so I’m hoping the Bob’s unit will be ok clearance wise.
 
675
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Hey 67GTA - I tried every possible hose location - diff and both axle tops - and I bought a whole bunch of lower profile and angled fittings. I even bent the reservoir brackets to push it up higher to no avail. The JLT was so much easier and has never rubbed. My car is lowered about an inch on coilovers, though.
 
This is what I've been using, no problems so far...

I switched to this exact system when I bought the Cortex Watts link and torque arm. First time I put it to the test at Watkins Glen it puked diff fluid everywhere out of the breather filter. I just went back to Bob's. I think having a larger reservoir to hold the boiling fluid (and no large breather filter) will result in less mess. I will likely get a diff cooler for next year.
 
I was considering the in-trunk catch can but worried about smell and fluid leak but VoodooBoss solved that problem. As he mentioned, the fluid stays in the system and cools then returns so there is minimal loss. The problem with the Cortex set-up is there is very little space for the fluid to gather and cool. Boiled fluid heads right to the nearest exit which is the filter. I typically did not have much fluid in the can as it all went out under the car. Since I have a torque arm I have the space where the UCA sat to attach Bob's can and let all that space and gravity do it's thing.
 

TymeSlayer

Tramps like us, Baby we were born to run...
3,787
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Brighton, Colorado
Have my AllStar can in the trunk area and much like Rick, never saw any evidence of fluid in the can. I suspect it never gets pass the line in. I do not vent mine outside and don't recall ever having any scent issues.
 

TMSBOSS

Spending my pension on car parts and track fees.
7,529
5,243
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10-20 Years
Illinois
Makes me wonder if we could simply run a line from the axel to the drivers side and zip tie the line to the fuel inlet. Terminate with a small breather filter. Should be 3-4 feet of line and will drain back since the filter would be a foot or so above the diff. Also being $80.00+ cheaper is not a bad thing.
 
Makes me wonder if we could simply run a line from the axel to the drivers side and zip tie the line to the fuel inlet. Terminate with a small breather filter. Should be 3-4 feet of line and will drain back since the filter would be a foot or so above the diff. Also being $80.00+ cheaper is not a bad thing.
I think that would work.
 
The advantage to the can from Bob’s and Shelby is that the fluid drains back to the diff as it cools. The cortex can as well as most of the cans mounted in the truck catch the fluids and hold them until drained.
You can replace the drain valve with a hose end and use that as your inlet to the catch can, then use the upper hose attachment to run the vent outside the trunk. Keep the vent or plug the opening.
 

TMSBOSS

Spending my pension on car parts and track fees.
7,529
5,243
Exp. Type
HPDE
Exp. Level
10-20 Years
Illinois
You can replace the drain valve with a hose end and use that as your inlet to the catch can, then use the upper hose attachment to run the vent outside the trunk. Keep the vent or plug the opening.

Agree fully. You may also be able to save the cost of the can and eliminate a hole in the trunk by keeping the system out of the trunk.
 
303
250
Exp. Type
HPDE
Exp. Level
3-5 Years
25 min. to 1½ hrs. from Sonoma (ugh... traffic!)
Just finished installing this kit for similar reasons. I was fighting clearance issues with lowered ride height and 3” OTA pipes burning the vent hose off. This caused the vent hole to plug on the last track outing and took the driver side wheel seal out. Ended up swapping the hose and fittings to low profile AN swivel fitting and AN push locks to get the clearance right. Overall this is a very high quality kit.

https://bobsmachine.com/product/mustang-2005-14-axle-reservoir-kr-style/

Where's the oil can ?
Brooke-Axle-Reservoir.jpg
 

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