Cab suspension air bags.

I've owned this 97 379 for 15 years and I have replaced the cab air bags every 3 to 4 years. The problem I have is it seems the rubber gets porous over time. I could be under the truck working on something and hear a slight hiss only to trace it to the cab air bags. I will spray them down with soapy water and they will have numerous spots where they start to foam the soapy water. I have a buddy with an 05 379 day cab he bought new and has never had to change them.

This all started for me when I opted to change out the original ones for new ones, not because the originals were leaking but because they looked like hell, the outer rubber was peeling away and I didn't want to chance one blowing out. Ever since then it's been every 3 years.

Is any one else having this issue?

I'm buying them from Peterbilt so I expected better quality. Has there been an influx off knock-off air bags I'm not aware of.

Will be buying 2 more tomorrow from Peterbilt, this is getting rediculous.

 

Thanks guys, I was beginning to think it was just my truck for some reason.

I have a big enclosure rack on the back so they don't see any direct sunlight. I did think about them cycling up and down too much but, I don't think that is the case. The truck doesn't lose too much air overnight. When it sits for 2+ days the bags will be deflated and sleeper sitting on the bump stops though.

Last set of bags I bought for the sleeper had push-lock fittings. The ones under the cab are still compression, I'll see when the new cab bags come if I have to convert to push-lock all around.