How do you move a bus when the brakes are locked?

[Sharkbait]

Bus starts and runs good, air bags come up, rocked back and forth a little when going from 1st to Reverse bus will not move either fwd or Reverse. The bus has been sitting for a number of years so I suspect the brake pads might be stuck to the drums. There is good air pressure. Does this sound right to you guys? I feel I'm so close I don't want to be defeated now. Ideas? Thanks, Phil

[Timkar]

Get it up to max pressure, release brakes and then push on the brake pedal as hard as you can for at least 10 seconds. Try this a few times before putting in to gear.
You may hear them release...

[Oonrahnjay]

Bus starts and runs good, air bags come up, rocked back and forth a little when going from 1st to Reverse bus will not move either fwd or Reverse. The bus has been sitting for a number of years so I suspect the brake pads might be stuck to the drums. There is good air pressure. Does this sound right to you guys? I feel I'm so close I don't want to be defeated now. Ideas? Thanks, Phil  

   Phil, I don't know specifics on your bus (like if it's spring parking/emerg brake configuration), but on many vehicles, you can check to see if the brakes release with a flashlight.  Engine doesn't have to be running, just good air pressure in the tanks.  Have someone else cycle the parking brake plunger (if they're spring brakes) and watch to see if the rods from the canister move the slack adjusters.  It's hard to see on many vehicles, but if you can get a good luck, that will tell you if the brake system is actuating the release for the parking brakes.  (For DD3 and other brake systems, you'll have to run checks suitable for those, but it may be possible to see the movement at the wheels.)  That won't tell you everything but it's a good place to start.

[gus]

As Tim says, try pushing on the brake pedal with the park brake off.

I don't know when DD3 brakes were first installed, if ever, on the 4106, but my 4107 has them.

I've never had either of my buses brakes stick, I live in the boonies and have to cross a couple of creeks with low water bridges.

[Sharkbait]

Well, I got the bus rolling. Seems like pressing on the brake for 10 seconds at full air pressure might have worked. The bus is on asphalt now. I ended up plowing through a fair amount of dirt though and the clutch was smoking pretty good. Even so, when the bus started to stall I had to push in the clutch to keep it from stalling out. It didn't seem to slip, I'll have to wait till it cools to see if I did any damage to it. Reason I ended up plowing through dirt was it looks like I lost at least 1 airbag on the passenger side rear. I need to jack and block the bus. I have 1 rear replacement airbag. My question is, where is the best place to put the jack and blocks? Is there a way to get this wrong? I was thinking of replacing all of the airbags anyway, not knowing how old these are. Fear of the unknown! Thanks guys, Phil

[digesterman]

Be careful with the clutch or you will be replacing it too, not fun

[Tony LEE]

Might be a good time to figure out how the clutch is adjusted for wear. If it is like the MC8, it is a simple procedure provided you can reach the knob.

[eagle19952]

Is there a way to get this wrong..

yes wrong enough that it can kill you...

i know you are asking...but if there is no one there to show you...well telling you may serve only to increase your risk...

be safe, Christmas is coming.

[digesterman]

Lots and lots of blocks on solid ground at the jacking points, get specs on your bus for proper jacking and blocking points, Don wasn't kidding when he said it could kill you

[Tom Y]

What model bus?

[eagle19952]

What model bus?

PD 4104 GM according to his post

[Lin]

I don't know for sure, but just guessing from your two questions you are early on the learning curve for this bus.  It would be massively useful to get the manual and dive into it.  Judging from your brake issue, it would seem that you have DD3 brakes.  DD3's do not release by merely pushing the parking brake valve-- they always require a full force foot brake application after pulling the valve.  So it is possible your brakes were not stuck at all but only acting as they should (if you really have spring brakes, forget this comment).

Your bus has very specific jacking points, and they are the only places you can lift it, although there should be other points that can be blocked once the bus is raised.  Anyway, that's the way it is on my 5a.  Aside from the manual, see if you can communicate with someone that has or has had the same model.  

Ask lots of questions and even repeat them until you are sure you have it right.  Everyone starts from zero and most of us are still learning bit by bit.

[eagle19952]

I don't know for sure, but just guessing from your two questions you are early on the learning curve for this bus.  It would be massively useful to get the manual and dive into it.  Judging from your brake issue, it would seem that you have DD3 brakes.  DD3's do not release by merely pulling the parking brake valve-- they always require a full force foot brake application after pulling the valve.  So it is possible your brakes were not stuck at all but only acting as they should (if you really have spring brakes, forget this comment).

Your bus has very specific jacking points, and they are the only places you can lift it, although there should be other points that can be blocked once the bus is raised.  Anyway, that's the way it is on my 5a.  Aside from the manual, see if you can communicate with someone that has or has had the same model. 

Ask lots of questions and even repeat them until you are sure you have it right.  Everyone starts from zero and most of us are still learning bit by bit.

actually that happens after you push the knob....usually flat, square and yellow...

[gus]

I don't know for sure, but just guessing from your two questions you are early on the learning curve for this bus.  It would be massively useful to get the manual and dive into it.  Judging from your brake issue, it would seem that you have DD3 brakes.  DD3's do not release by merely pulling the parking brake valve-- they always require a full force foot brake application after pulling the valve.  So it is possible your brakes were not stuck at all but only acting as they should (if you really have spring brakes, forget this comment).

Your bus has very specific jacking points, and they are the only places you can lift it, although there should be other points that can be blocked once the bus is raised.  Anyway, that's the way it is on my 5a.  Aside from the manual, see if you can communicate with someone that has or has had the same model.  

Ask lots of questions and even repeat them until you are sure you have it right.  Everyone starts from zero and most of us are still learning bit by bit.

My 4107 DD3 brakes are released by pushing in on the button. Pulling out sets them.

Also, 99% of the time mine releases, after a very slight pause, when the button is pushed in. Those few times it doesn't I almost never have to push the brake pedal more than a tiny bit.

However, I never push very hard setting it either unless on a very steep incline. Usually I don't push the pedal at all when setting it.

My button is round and black:)

Axles are the only really safe jacking points. If you must jack the body try to do it at a suspension point on the body. If that isn't possible jack at a body bulkhead point and then don't get under it until the axle or suspension point is supported. These old Al bodies suffer internal corrosion so are unpredictable. When new they are strong, but old age often takes that away.

When replacing air bags you have to somehow lift the body from the axle but be sure to block between the axle and body when you do.

[luvrbus]

I use a 8 ft piece of 4in I beam with jacks on each end to raise the body then block between the axle and body for safety  JMW