Rear Shock Replacement?

[Josh D]

Hi guys,

I bought a 2016 GMC Yukon XL Denali and looks like the rear shocks are already starting to leak. I am new to Magnetic Ride shocks, but can't figure out why the shock looks to be leaking in the air bag portion of the shock.

Can someone chime in and let me know if this is the shocks leaking or something else related to the air bags?

I noticed that issues can involve the air compressor and wondered if maybe it could be related as well.

Thanks in advance for all of the help!

 

[JonnyTahoe]

Looks like a Leak.

 

[Big Mama]

Looks like the shock seal is leaking. How often do you hear the compressor running? Is there anything else around the shock wet? @iamdub has a bit of experience with these too.

 

[RST Dana]

@RockAuto has what you need. Usually has a discount code here as well. Lifetime warranty for my replacement that took 39 minutes to swap out.

 

[iamdub]

It looks like an oil and it looks like it's coming from the shock since there's nothing else around there that would wet it just in those areas. I'm thinking that odd, sharply-defined sloped part at the top of the shock in two of the pics is a shadow that's screwing with us.

Yes, the compressors eventually fail, but what usually happens is the bellow on the shock wears and develops a leak. The leak makes the compressor run longer and more often than usual, so its already aged life is accelerated and it tends to fail soon after cuz nobody really notices the shocks leaking.

 

[Josh D]

So is the fluid leaking out of the top of the shock and when the air bag inflates, the fluid is being pushed out of areas that are leaking air? I squeezed each air bag and it seems there's a little air in them, but I can easily push in on the air bags. I have heard the compressor kick on a few times, but doesn't seem like it stays on for very long before turning off.

It's going back to the dealer in a few weeks for some other repairs as part of the purchase and they are supposed to look at the shocks. Just concerned they are going to kick the can down the road, tell me this is normal so they don't have to eat the repair and will become my problem later.

 

[RST Dana]

So is the fluid leaking out of the top of the shock and when the air bag inflates, the fluid is being pushed out of areas that are leaking air? I squeezed each air bag and it seems there's a little air in them, but I can easily push in on the air bags. I have heard the compressor kick on a few times, but doesn't seem like it stays on for very long before turning off.

It's going back to the dealer in a few weeks for some other repairs as part of the purchase and they are supposed to look at the shocks. Just concerned they are going to kick the can down the road, tell me this is normal so they don't have to eat the repair and will become my problem later.

Neither fluid not air should leak out of the shock. Either one requires a shock replacement.

 

[iamdub]

It's probably not leaking air... yet. The air bellow is a sleeve bag that rolls over the shock body as the suspension cycles. Picture the bellow as a doghnut, but tall and with a shock passing through the center hole. Shocks start leaking from the seal where the rod slides in and out. Since the shock rod is inside the center of the "doughnut", the leaked oil will collect in there and will seep out whenever and wherever possible. It looks like it's seeping out lower down the shock body and getting smeared up and down the body as the shock and bellow is compressed and extended.

When parked, the bellows will only have about 5 psi in them. A few seconds after cranking the engine, the system will run the compressor for about 5 seconds as a self-check and to put a minimum amount of air in the bellows so they hold their shape while driving. If the vehicle is loaded down, the compressor will run to fill the bags more to lift the vehicle until the sensors indicate the vehicle is at its preset height.

 

[Josh D]

It's probably not leaking air... yet. The air bellow is a sleeve bag that rolls over the shock body as the suspension cycles. Picture the bellow as a doghnut, but tall and with a shock passing through the center hole. Shocks start leaking from the seal where the rod slides in and out. Since the shock rod is inside the center of the "doughnut", the leaked oil will collect in there and will seep out whenever and wherever possible. It looks like it's seeping out lower down the shock body and getting smeared up and down the body as the shock and bellow is compressed and extended.

When parked, the bellows will only have about 5 psi in them. A few seconds after cranking the engine, the system will run the compressor for about 5 seconds as a self-check and to put a minimum amount of air in the bellows so they hold their shape while driving. If the vehicle is loaded down, the compressor will run to fill the bags more to lift the vehicle until the sensors indicate the vehicle is at its preset height.

Thank you so much for that explanation. Now I understand what's going on. Should I press the dealer to get these replaced, or are they really fine till they either start dripping on the floor or totally cease up? I have read on other forums that can be the lip service from service advisors when trying to get shocks replaced.

 

[Sangster]

Those 100% appear to be leaking. I would press for them to replace them.

 

[iamdub]

A leaking shock is a bad/failed shock- Period.

Because they're expensive, not pouring oil all over the ground and the air bladder (apparently) is still good, they're sure to put up a fight. Knowledge and setting the tone that you're not coming at them half-cocked are good power moves: Do you have any literature on your particular warranty? If the suspension is included and outlined in it but if it doesn't specifically say "minor weeping/leaking" from the shock, then it should be pretty cut-and-dry. You have a failed part(s), let's hope the warranty details agree with us.

 

[avalonandl]

Those shocks are $ 240 apiece on Rock Auto....thats for a 2012 Denali which I have....

 

[olyelr]

A few seconds after cranking the engine, the system will run the compressor for about 5 seconds as a self-check and to put a minimum amount of air in the bellows so they hold their shape while driving.

I have read this somewhere else before. But, my wifes denali does not do this ever. Hasnt in its first 90k miles anyway. It does, however, still air up the shocks when needed to level the vehicle off.

 

[Big Mama]

How about with remote start? What year Brandon?

 

[olyelr]

How about with remote start? What year Brandon?

My wifes denali is a ‘16.

To be honest, I have never listened for it with remote start.

 

[Big Mama]

Wonder if the K2XX have a different setup where they hold air better. Mine usually come on in the morning at start up after losing a little air overnight.

 

[BG1988]

Wonder if the K2XX have a different setup where they hold air better. Mine usually come on in the morning at start up after losing a little air overnight.

no, that is because COLD air is denser hence looking like you lost air