Lumbar Pump Help Needed
Thread Starter
Racer
Joined: Jun 2019
Posts: 390
Likes: 126
From: Franklin, TN
Lumbar Pump Help Needed
1993 with Sport Seats. Read some posts and watched some You Tube vids for lumbar repair. I have put new blood pressure bags in my seat backs and put a bicycle tube diaphragm in my lumbar pump. The pump runs fine but pumps no air. When I took the diaphragm sub-assembly apart and opened the tube nipple side, I found 4 cone shaped rubber boots. Three of the boots were in the 3 air tube passages and the 4th was in the air intake. I AM ASSUMING STARTING HERE! It appears that the mouth of the boots (a small slit in the end of each) open and close depending on intake or output cycle (the 3 tube boots appear to open on a pump and close on intake. It appears the air intake boot should open on intake and close on pump. However, the slit in the intake boot is much more open (slit area on tip of boot may be damaged or deteriorated) and is apparently letting pumped air back out the intake.
My question- Is that how this pump system works? AND, if so, does anyone have a fix/workaround for this problem (I am assuming I cannot purchase the rubber boot)? If it doesn't work like that, what should I check for a fix?
My question- Is that how this pump system works? AND, if so, does anyone have a fix/workaround for this problem (I am assuming I cannot purchase the rubber boot)? If it doesn't work like that, what should I check for a fix?
Thread Starter
Racer
Joined: Jun 2019
Posts: 390
Likes: 126
From: Franklin, TN
Lumbar Pump Fix
I have been talking to myself on this thread but I wanted to document my lumbar pump fix here. After installing new bags (blood pressure) and a new diaphragm (the usual failure point for the lumbar pump), I still had no air flow. I opened the hose nipple side of the diaphragm sub-assembly and found the large rubber boot on the intake opening had a gaping hole in it, preventing it from properly closing and preventing air backflow. The 4 rubber boots, 3 to air hoses and 1 at intake opening, act as a one-way check valves to get air to flow to the bags. I could not find a replacement boot, so I found several plastic one way check valves available on Amazon. I purchased the one pictured above ($5 for a bag of 5) and installed it as shown in the second picture, I removed the small metal screen over the intake opening, inserted a tight fitting tube in the opening, sealed it with some silicon adhesive and then inserted the valve into the other end of the short tube. Not sure about long term but so far it is working very well. I now have working lumbar support on the seat!!!
