Parking brake woes !

[Jeremy Parrett]

Ok, so I drove about half a mile before I realized the parking brake was still on !
  Now; it will only hold the coach on a billiard table surface.....any slope at all and off she runs !!
I need to know how to locate the parking brake and adjust it if possible. 
Can the brake pads be replaced and where would I buy them ?
2000 Marquis Amethyst.

[Tom and Pam Brown]

Jeremy, first you may simply need an adjustment on the brakes. Even though th coaches have slack adjusters they still need to be manually adjusted from time to time.  If you are stopping when driving that means the front brakes are doing all the work.  There are pads and parts available no issue with that.

If you are not comfortable with doing the adjustment, find a heavy duty truck dealer and they can perform the task as well replace pads if need be.

[Jeremy Parrett]

Tom and Pam,
   thank you for the info.  This is an issue that must be dealt with here in Las Vegas asap.   Jeremy

[Tom and Pam Brown]

There are quite a few YouTube videos on how to adjust the slack adjuster.  All it takes is 3/8" wrench and a flat head screwdriver.  My number is in the directory if you wish to discuss the process.  It is quick and fairly self explanatory.

[Edward Buker]

Jeremy,

The slack adjusters are automatic as well as manual adjustment. Try and air up and keep the air above 90lbs reserve air in your tanks, turn off the parking brake and hold the brake pedal full on hard for a few seconds, do this several times. If they are working properly the slack adjusters should take up the slack. Then try your parking brake again and see if it is working normally. You should make this hard on brake adjustment part of a routine once a week when you are traveling and normally using the brakes.

You should still probably go in for a rear brake check to be sure that the rotors are not cracked beyond spec due to overheating issues and that there is sufficient brake pad left. If you want to check it yourself Meritor has the crack spec in the brake manual available online and a technique for measuring remaining pad by using an exposed metal shaft for measurement on the back of the caliper mount. A little 6 inch metal rule with a slide T on it is handy for measuring this arrangement. Be careful if you are going under the coach, if possible support the frame.

Later Ed

[Keith Moffett]

Jeremy
If you can get up to Eugene, Kaiser brake and alignment did a great job on ours.  We had them strip and inspect all six wheels and clean and relube the Meritor system.  They found that the front pads looked great before disassembly but were so rotted they fell apart on service.
Once the system was fully serviced, the pads disengaged from the rotors smoothly and it made a real difference.  I hadent even realized the brakes were draging.
Kaiser has all the parts for Meritor because they do them on busses and all the high end coaches.  I believe there were eight coaches in the shop with ours.
Kaiser Brake and Alignment
Eugene, Or.
541-344-5887

[Jeremy Parrett]

Ed and Keith,
   great info.  I will try the brake adjustment  routine when we air up to leave the Park.   I will get the brakes checked asap.  It wont be Eugene Oregon though.....we are planning on being up there in the summer !!
             Thanks,   Jeremy

[Jeremy Parrett]

   At P&V Diesel in Indio.California for parking brake service.
    The passenger side drive axle disc is toast....huge deep grooves.  The tech is going to replace the passenger side disc and all the  pad sets front ,rear and tag axle . These are all  air disc brakes.. 
   At the front we were going to upgrade the T20 actuators to T30's to match the rears   .
 The tech talked to the Meritor dealer here and explains this is not a good idea and here is why:
 1.  The T30 actuators are too large and will contact the wall.
 2.  The rear T30 actuators work both the drive axle and tag axle disc calipers so T30's on the front would upset the balance and cause the front brakes to overwork.
      He is going to install "helper" springs on all the calipers.
  Parts on order......I will update this when the work is done.
  There are brakes on the tag axle......who knew  !!! With only one rear drive axle  brake working it was no wonder the parking brake didn't work !!
We are asking Meritor if it is possible to cause the Midland Parking brake to actuate all the brakes and not just the drive axle .
 The tech mentioned that correct downforce on the tag axle is essential to  ensure that the tag axle brakes work with the drive axle brakes  to give even braking.
 I had the tag set too light last year  causing the tires to skid,  ruining 2 tires.
 

[Jerry Emert]

   At P&V Diesel in Indio.California for parking brake service.
    The passenger side drive axle disc is toast....huge deep grooves.  The tech is going to replace the passenger side disc and all the  pad sets front ,rear and tag axle . These are all  air disc brakes.. 
   At the front we were going to upgrade the T20 actuators to T30's to match the rears   .
 The tech talked to the Meritor dealer here and explains this is not a good idea and here is why:
 1.  The T30 actuators are too large and will contact the wall.
 2.  The rear T30 actuators work both the drive axle and tag axle disc calipers so T30's on the front would upset the balance and cause the front brakes to overwork.
      He is going to install "helper" springs on all the calipers.
  Parts on order......I will update this when the work is done.
  There are brakes on the tag axle......who knew  !!! With only one rear drive axle  brake working it was no wonder the parking brake didn't work !!
We are asking Meritor if it is possible to cause the Midland Parking brake to actuate all the brakes and not just the drive axle .
 The tech mentioned that correct downforce on the tag axle is essential to  ensure that the tag axle brakes work with the drive axle brakes  to give even braking.
 I had the tag set too light last year  causing the tires to skid,  ruining 2 tires.

Jeremy, your post brings up a question in my inexperienced mind.  Tag axle downforce.  What is enough?  Last year when I weighed my coach I discovered that my front axle was overweight.  I backed off on the force in the tag to lower the rear end a little and am now under max on the front axle.  I haven't had any problems with braking or parking brakes, so just wondering?  Thoughts?  Thanks in advance.
Jerry

[Jeremy Parrett]

Jerry,
 You must weigh the tag and front wheels to establish the correct load distribution adjusting the tag axle downforce accordingly.

[Jerry Emert]

Jerry,
 You must weigh the tag and front wheels to establish the correct load distribution adjusting the tag axle downforce accordingly.

Jeremy, exactly what I did!  Always studying and trying to learn this Baby!
Thank you.
Jerry

[Lee Welbanks]

Just wondering here, "What would be the proper load on the tag axle"? Is it written someplace? I unloaded weight from the front by dropping the tag air pressure, the tag had way to much load. Checked by reading the temps of all the tires after a couple of hundred miles in hot weather the tag tires were hotter than the drive axle, now I'm only running about 6K on the tag and about 27K on the drive, front end is still almost 14K. These coaches are way to front end heavy for my liking.
Saw a brand new Newall coach that had wide based singles on the front with a 24K axle, pretty soon they'll need a overweight permit to go down the road. I would hate to blow a front tire with that much weight.

[Jerry Emert]

When I bought the coach and had it weighed for the first time the front axle was a little over 1K overweight.  Supposed to be 12.8K front.  Folks here on the forum advised me to let some air out of the tag to shift some of the weight back towards the rear.  I set the pressure to about 24 and the next weight was about 400 Lbs under the limit.  I couldn't get a 4 (6) corner weight so I was stuck with a weight of 23,140 on the rear.  No idea how much the tag is picking up.  That's where it sits now.  Probably need to get another weight, we've added a bunch since then.  So I guess as long as the front weight is within specs I'm happy.

[Lee Welbanks]

If your ever traveling down a interstate on the weekend see if you can find a DOT highway scale that is closed, usually they leave the scale on and the read out screen up so you can just pull in there and weigh to your hearts content.

[Jeremy Parrett]

 Good thought !! I will make a mental note Lee.   Wonder if California allows this ?