Sport Seat Repairs and Upgrade

[ZR1Vette]

My ZR came with the typical lumbar air pump failure...specifically the Jasco air pump membrane was shot...either the electric motor was not turning due to plunger jammed against pump housing or the motor was spinning due to plunger being torn from pump membrane thus nothing was happening..
This is the Jasco pump (BTW..appears that they no longer are in business...number listed for them is now reassigned to another company)


and pump end plate removed showing the plunger (P>) torn from membrane (<M) and jammed to one side.


Now to the repairs and upgrades... actually was easier than it expected...AFTER I figured out a few tips to ease process of removing the lumbar pumps. First you remove (do not need to totally remove and can move to one side or other) the seat cushion..
Pop this clip back (use a short screw driver and place between retainer and seat bottom and just push down and back) to release the seat cushion... marked with red <--

The white > marks the three 8 mm bolts holding the lumbar motor in place..these are a PIA to get to due to tight spaces, but I have a little trick to make things easier...

Once seat cushion is released and moved out of the way this is what you see:


Few comments:
-All of the air lines connectors (red >) were broken and separated...the connector material appears to harden over time and becomes brittle so if you see little chunks of a whitish plastic type material under your seats..well that is the connectors falling apart.
-The seat trapeze (wide straps for supporting the foam of the seat cushion) only has two straps yet there are connector sites for four straps..not sure why only two straps are there??
-The Jasco air pump is at the top right of the picture (passenger side) and would be on the bottom right if the drivers seat

Now to pump removal... here are two tips.. move the seat into the highest upward position and move a foward position (using the seat controls on the dash ('90)...
and
remove the two bolts shown (marked <B) and this will allow you to raise the seat pan up about 1" (place a socket between seat rail and pan to keep it in the raised position) and this will greatly ease access to those little 8 mm bolts


Next remove Jasco pump and replace (what I did) or try and repair pump (plunger and membrane) as some have done..there are two electrical connectors to pump (is obvious which two connectors) to unplug to remove pump. Reinstall new (or repaired pump)...now to another tip...if you get a new pump the air line connector is included...in this pic you can see (marked <new connector) BUT if you are repairing pump and/or have the connector failure (crumbly connectors noted earlier) a very easy fix is to connect the various air line nibs with 1/4" tubing..you can see this in this pic..just above the word 'connector'



Once pump is reinstalled and all air line connectors are reattached couple other things you can do while seat cushion is up... clean up and lube (I highly recommend Wurth HHS 2000 spray lube) the screw drive for the seat back adjustment and acquire and install a additional seat trapeze straps ('new support' in picture) in the middle position and place the one that was in that position to a outer position thus you are adding an additional strap and using the tighter newer one in the middle for more support.
Remove the socket used to separate seat pan from rail assembly and reintall the two seat pan to seat rail assembly bolts.
Reinstall the seat cushion (slide rear in first and just prior to setting in place take a peak at wiring and tubing to make sure no kinks etc exist... then make sure front clip (the thing you first moved to release seat cushion) is in slot and reclip.
Your done... lumbar now functions and your seat bottom is more supportive

Michael

[key_on]

Great write up. Thanks for sharing. I recently had to repair broken air line connectors on mine, but fortunately, the pump still worked fine. I also notice the missing support straps, but figured it was just an oversight when it went down the line. I think I'll add one just as you suggested.

Pat

[Aurora40]

I wondered why the seats had room for four straps but only used two as well. I bought the MAM replacement straps as mine were pretty iffy. I thought about putting the originals in the outer positions as you did, but decided not to. They seem to do fine with just two straps.

[DaveK]

Nicely done. Great to see more of these write ups coming along. Thanks to everyone.

Michael, it's just as easy to remove the whole seat to get to those 3 bolts. And what you will also typically find is that the plastic on the pump mount is broken after being overtightened from the factory.

Good write up.

[Polo-1]

Originally Posted by Jeffvette

Michael, it's just as easy to remove the whole seat to get to those 3 bolts.

Good write up.

Unless it's a 94 Admiral Blue car. Then NEVER try and remove the seats.
8 studs to holds 2 seats, my luck 4 broken studs

Originally Posted by Polo-1

Unless it's a 94 Admiral Blue car. Then NEVER try and remove the seats.
8 studs to holds 2 seats, my luck 4 broken studs

I said remove the seats, not the seat track.

[ZR1Vette]

Originally Posted by Jeffvette

Michael, it's just as easy to remove the whole seat to get to those 3 bolts. And what you will also typically find is that the plastic on the pump mount is broken after being overtightened from the factory.

Good write up.

Good option...probably would make things easier, but I was being cautious about how much I was unbolting etc..learning curve thing
Michael

[flyin ryan]

well done , great heads up for those who have never done one. it's really not that bad to do.