Mack Rearends

[roscoe]

I have mack 44,000 rearends, i had a problem with the vents plugging on both rearends and then losing the pinion seal so i put a set of stemco esp vents on about 3 months ago.

I thought i would inspect them and removed both vents. They both had alot of air pressure release when removed. Is anyone familar with the esp

style vents? is the pressure build up normal ? seems like it will cause a wheel or input/output seal to fail.

[rhasler]

I have mack 44,000 rearends, i had a problem with the vents plugging on both rearends and then losing the pinion seal so i put a set of stemco esp vents on about 3 months ago.

I thought i would inspect them and removed both vents. They both had alot of air pressure release when removed. Is anyone familar with the esp

style vents? is the pressure build up normal ? seems like it will cause a wheel or input/output seal to fail.

I had an experience where someone installed one on a Mack T300 transmission and it did the same thing. Seems like it was building too much pressure in the case of the transmission and pushing oil into the range valve causing it to push oil out of the valve's cover.

[rhpaulin309]

The originals mack vents can last a long time but do require TLC depending on local conditions. I have two sets of vent that i alternate twice a year.While one is in use the other sits in a jar of brake cleaner for a while.Cheap but efficient!