AboutRobert Summers Expertise domestic auto/truck repair, auto body, painting. I currently own a large auto/truck/marine repair shop. 40 years certified 310S,310T,310B in ontario Canada
Experience 40 years certified 310S,310T,310B ontario qualified, 7 years with GM have owned my own shop now for the past 27 years.was automotive marketing director for large auto parts supplier.
Organizations CFIB (current) past member AARO and APAA.
Education/Credentials grade 12 plus 2 years college. many aftermarket training courses
Question I have a 1989 Chevy 1 ton dually that has air in front brake system. I have changed front calibers brake lines and proportioning valve and bleed lines. When I start pumping the pedal it gets firmer but when I stop for a minute it goes all the way to the floor again. I have bleed the brakes for hours and still no luck. Is there anything I could possibly be overlooking?
Answer Hi Sharon... Bleed the master cyl... you have air trapped in it. then rebleed the system after you get all the air from the master.also make sure that the centering valve is in the center while bleeding. (proportioning valve) hold the pin on the end in the center while bleeding after you get air from the master... hope this helps
