As mentioned previously, I recently adjusted my brakes, but I'm thinking that they should be tighter than I made them. Should the engine be able to overcome the DD3 brakes when they are engaged? It seems that it can do that now at about 1200 rpm. I had backed off 1/2 turn from tight. Maybe I should go down to 1/4.
Standard is 1/4 turn back, but what is very importand is the 90 degree angle of the slack adjuster arm to the push rod at full application.. Not under 90 or over 90. >>>Dan (sometimes the clevis at the push rod needs to be adjusted to achieve this)
standard is to measure the brake stroke, not to back off some arbitrary amount from tight. If you are going to adjust your own brakes, at least learn how before you do it.
Do you know how to perform the DOT mandated test for brake stroke? At what pressure do you measure it, how do you measure it, and what is the correct range for the brakes on your bus?
It's not brain surgery Lin your uneven ware is probably part of the problems like the pins and spring are wore out.
You know when a shop hires a new guy after he graduates from sweeping floors his next stop is installing brakes.
Check the limit on your DD3 they have a limit gauge on the push rod if you can see the limit marker you need to figure out why
Lin, hi!
heres a straight up procedure I was taught a few years ago; have a full supply of air in the system, block all the other wheels, release the park brake and confirming no vehicle movement then jack the wheel off the ground you are adjusting.
dot best spec is 1/2"-3/4" rod movement, this also should be correct rod angle if any major replacement was done as the angle should have been set proper by the wrench doing it.
or that's what I was tested on.
When adjusted to a full loc or applied, I was taught its best to first check that no drag at 1/4 if so 1/2 that's the reason for jacking and I'm sure a lesson for myself, it was a good one. If there was a drag a wise choice to take a better look and usually remove the cover for a look see.
If you happen to be close to a truck shop at the parts counter they probably have a stack of card board or even plastic angle measure "templates" given to them by the brake mfg's. they pass them on to the techs and customers.
any more questions feel free to ask
have a good day
Floyd
to answer the question. no, the bus should not move thru the brakes at 1200 rpm.
with the brakes applied (park and foot), one should be able to stall the bus.