Two things: John Deere chassis div was bought by Oshkosh and now belongs to Freightliner so you can call them for help; also try
contacting Alice McGrath at John Deere: 319-292-8703 or McGrathAliceR@johndeere.com. Nice lady, very helpful and knowledgeable. She will need your VIN number. She was able to send me a complete set of photocopies of the chassis manuals for my last MH. FWIW, a diesel was available as an option on the JD chassis, and the brakes used a HydroMax booster (sounds like yours isn't working properly)
