01-29-2021, 06:50 PM
I finally got the ISRI Air Seat repaired. Looking back had I purchased all the supplies I needed before I started it would have gone much faster. I think someone had modified the seat in the past as there was a 3/16 OD line along with others that were 4mm. Walt Preston had mentioned that his seat had 4mm lines and given that these are German seats the metric seems more logical. When we got the coach the air line to the seat and one under the seat cushion itself had just been crimped off to stop the leaks in addition to an attempt to glue one of the tees which had failed.
As a result of the differing air line sizes it was necessary to obtain fittings and adapters to accommodate both sizes. Fortunately McMaster-Carr www.mcmaster.com had all the parts needed. The parts are listed in the attached photos. It's important to know both the OD and ID measurements because at least in my case the least misfit allowed air leakage. As it turns out 4mm ODx2.4mmID will tightly fit a 3/32" fitting which was what I ultimately used for the connections.
Prior to starting work on the seat I shut off the 120V compressors by removing their fuse on the fuse panel in the electric bay. Then I removed the crimped 1/4" air line tubing and spliced in a 1/4" brass valve so I could isolate the chair for work now and in the future. I remember reading about the surprise one of our members had when his seat airline blew while he was on the road necessitating a change of underwear.
The actual process:
1. Remove the seat cushion held by spring clips and lift off.
2. Remove seat pan secured by 2 hex head bolts which allow the seat to move forward and aft. Once those 2 bolts are removed the seat pan slides forward off white nylon guides on the sides and clear 2 round head retainers on the front.
3. Identify where the leaks are
4. Disconnect, unbolt, and move electric motors if necessary
5. Measure for lengths of tubing needed
6. Create clean 90 degree ends on the air hoses
7. Insert proper fittings and connect air line tubing
8. Test for leaks
9. Rebolt and connect motors if necessary
10. Replace the seat pan, most easily done if the front of the seat is tilted up and the seat is full forward. This allows the pan to clear the support frame below it and will allow an average size hand up into the mechanism to place the fore and aft drive mechanism in position where the bolts on top of the pan can reach the threads of the mechanism to secure it. If for some reason you can't get a hand in there a long piece of dental floss threaded thru the front hole of the mechanism and up thru the pan can pull the mechanism close enough to get the rear bolt started. That will hold the mechanism close enough to get the front bolt started once the floss is removed. Always good to floss anyway.
9. Replace the seat cushion and you're done.
You'll see one quick connect fitting in the repair photos. I could not get a barbed connector to seal while the quick connect did. I was surprised.
Time to complete the job, if all the parts are available 1-2 hours. Degree of difficulty-novice
Thanks to Walt for supplying the seat diagram and alternate source for the 4mm tubing if needed
As a result of the differing air line sizes it was necessary to obtain fittings and adapters to accommodate both sizes. Fortunately McMaster-Carr www.mcmaster.com had all the parts needed. The parts are listed in the attached photos. It's important to know both the OD and ID measurements because at least in my case the least misfit allowed air leakage. As it turns out 4mm ODx2.4mmID will tightly fit a 3/32" fitting which was what I ultimately used for the connections.
Prior to starting work on the seat I shut off the 120V compressors by removing their fuse on the fuse panel in the electric bay. Then I removed the crimped 1/4" air line tubing and spliced in a 1/4" brass valve so I could isolate the chair for work now and in the future. I remember reading about the surprise one of our members had when his seat airline blew while he was on the road necessitating a change of underwear.
The actual process:
1. Remove the seat cushion held by spring clips and lift off.
2. Remove seat pan secured by 2 hex head bolts which allow the seat to move forward and aft. Once those 2 bolts are removed the seat pan slides forward off white nylon guides on the sides and clear 2 round head retainers on the front.
3. Identify where the leaks are
4. Disconnect, unbolt, and move electric motors if necessary
5. Measure for lengths of tubing needed
6. Create clean 90 degree ends on the air hoses
7. Insert proper fittings and connect air line tubing
8. Test for leaks
9. Rebolt and connect motors if necessary
10. Replace the seat pan, most easily done if the front of the seat is tilted up and the seat is full forward. This allows the pan to clear the support frame below it and will allow an average size hand up into the mechanism to place the fore and aft drive mechanism in position where the bolts on top of the pan can reach the threads of the mechanism to secure it. If for some reason you can't get a hand in there a long piece of dental floss threaded thru the front hole of the mechanism and up thru the pan can pull the mechanism close enough to get the rear bolt started. That will hold the mechanism close enough to get the front bolt started once the floss is removed. Always good to floss anyway.
9. Replace the seat cushion and you're done.
You'll see one quick connect fitting in the repair photos. I could not get a barbed connector to seal while the quick connect did. I was surprised.
Time to complete the job, if all the parts are available 1-2 hours. Degree of difficulty-novice
Thanks to Walt for supplying the seat diagram and alternate source for the 4mm tubing if needed
Sandy and Bob McBratney
Previous owners of 2007 Newell #1202 "Boomer"