Hi All
First thanks to Rob and David for responding.
First to David's comments/questions:
I don't think there is any significant differences in the pairs of backing plates. But David your comment made me check the position of all eight of the lower/major adjusters. The 4 rear ones were dots pointing toward each other. While the 4 front ones are at the 2 and 10 o:clock positions.
Second Rob's comments- "I would suggest you try a major adjustment again" Well I did a careful major adjustment per the manual:
10. Was getting a stead 30 lbs. pressure on the peddle.
Getting just 30lbs peddle pressure is a touchy thing, wish the manual explained the logic. You can see from the photo how this was done with a 30lbs with hanging pulley so as to put just that pressure on the peddle. This pressure seems to just take up the play in the wheel cylinders, without applying the brakes to drag. If you push down on the peddle just a little more and release the brakes apply and the wheels don't turn. So I went with just 30 lbs pressure.
11. With a short (3")wrench turned the two lower pins on each wheel just the smallest amount to just cause brake drag/sound. Repeated this on all the wheels carefully re-tightening the locking nuts. When the pressure was removed the wheels turned smoothly with no drag.
Robs last point is well taken "If the shoes are correct, and you are still finding the need to pump the pedal, then perhaps a good bleeding is in order. Fresh fluid in the system is a good thing, and a preventative maintenance item that is often overlooked." Because all CMPs have single brake systems I take preventative maintenance seriously. Any sign of leakage means full brake job. No leakage every 9-10 years replace all the rubber parts in the brake system, cups, boots, lines and of course flush the brake system. Last done on this truck 2015.
Ok after very carefully doing the FULL brake adjustment procedures tool the truck out for test drive, following observations:
1. Peddle right at the top of the stroke
2. Brakes apply very briskly
3. Did several full hard stops from 30-40 MPH nice and straight with good braking. Could not lock the wheels but, but close. Now stops nicely on 9% down grade, which was one of my prior concerns, it just didn't feel like it wanted to, now it stops nicely.
4. After 6-10 hard stops checked the brake drum temperatures LF 136, RF 122, LR 130, RR 129 Degrees Fahrenheit with IR Gun.
Only time will tell if the Right Rear goes out of adjustment, but I have added witness lines to all of upper adjustment so will be able to tell if its shoe wear or the adjuster moving.
Cheers Phil