Lumbar problem

[Tonka329]

I have been cruising the stickys and I didn't find any info on the power lumbar drivers seat. I just bought a '96 Z-71 yesterday and it feels like the lumbar is all the way out. I hit the button to raise it, you can hear the motor run and hear a "hissing" also. I push the switch the other way and nothing happens. Is there anyway to fix this or will i need to search the salvage yards for another seat? Thanks in advance!

Tonka

 

[sewlow]

That lumbar support is a square plastic bag that has an intake & an exhaust valve.
That exhaust valve does 2 things. It'll hiss when deflating & when the bag reaches max. pressure it will bleed off the excess air if the pump is kept running via the switch.
The fact that it hisses when it reaches max. pressure indicates the valve is working.
Check the switch (notorious for dying,) the wiring to the pump motor & valve. IIRC, there's a relay in there somewhere.
Sometimes the wires will get abraded over the years. As the foam compresses over time, the wires may move around to just the right spot & end up rubbing & wearing against a frame rail or bracket. Or they could be pinched somewhere along the line.
Best to pull the seat & get it up on a bench to do this. Make sure that the seat is at it the front of it's travel before you disconnect the harness. That way, once it's outa the truck, it'll stand up on it's own without falling over backwards.
You'll need a 12v power source with some wire to hook it up to the seat harness once the seat is up on the bench.
You have to undo the bottom of the backrest cover. It's a zipper.
Gotta roll the cover up far enough to get at the lumbar bag & mechanisms. If you have a fold down armrest, you may have to remove it. Or you might not have to, if you can get at that stuff with the amount that the cover can be rolled up. Been a while since I had one of these seats apart. Memory has gone for a ****.

 

[Tonka329]

Thanks for the reply. Is there anyway to deflate the bag without removing the seat? I don't feel the need to have this bag aired up and punishing my kidneys every bump the truck hits.

 

[sewlow]

You could try removing the line from the pump to the bag. This way, you' can fix the prob properly when you get the inclination.
If you don't intend on ever using the lumbar again, cut that line or stab the bag.

 

[df2x4]

Throwing another question out here as I have a different lumbar problem. The lumbar in my Suburban seems to operate normally except all the air in the bag likes to escape about 30 seconds after I pump it in there. Would this more likely be a leak in the bag itself or the exhaust valve that was mentioned malfunctioning?

 

[sewlow]

Could be that the bag or the line has developed a hole. Maybe the valve or one of the line connections has failed.
Only way to find out is to start digging into the seat & testing the complete air system for that lumbar support.

 

[df2x4]

Will do, another thing added to the list for when my neglected seat finally gets some attention. Thanks for the input.

 

[Tonka329]

I guess I can just stab the bag! I'm used to doing that... I have 2 kids

 

[sewlow]

Lol!!

 

[Tonka329]

Well, the bag was not inflated. I pulled the panel away from the seat back to see it. It looks like that part of the seat is not worn out? HMMMM...