Air brakes at 0 lbs in storage

Topic: Air brakes at 0 lbs in storage (Read 1690 times) previous topic - next topic

Air brakes at 0 lbs in storage

October 31, 2021, 06:20:37 pm

I have stored my coach for winter. I realize I have a leak in air tanks or something which i will deal with in the spring. My question is my brakes and emergency air brake still active? I have all wheels chocked but some reassurance that the brakes are still applied even though the pressure reads zero would be appreciated
Peter

Re: Air brakes at 0 lbs in storage

Reply #1 – October 31, 2021, 06:24:38 pm

The park brakes are spring activated and released by air pressure

This applies to the rear brakes only.................

Re: Air brakes at 0 lbs in storage

Reply #2 – October 31, 2021, 06:27:30 pm

If your air pressure gauges read "0" then your service brakes will not work. They are applied by air pressure. However, your parking (emergency) brakes on the rear axel will be set and functioning because they are applied by heavy mechanical springs. The parking brakes should activate automatically when pressure in the brake tanks gets down around 40 psi.

You will not be able to release the parking brake next spring until you build air pressure in your brake tanks above (about) 60 psi.

Re: Air brakes at 0 lbs in storage

Reply #3 – October 31, 2021, 07:44:57 pm

CORRECT.

Re: Air brakes at 0 lbs in storage

Reply #4 – November 01, 2021, 01:50:32 am

Thanks for the explanation I take it the coach will not roll at all throughout the winter. Wheels are chocked and the pad is very very level

Re: Air brakes at 0 lbs in storage

Reply #5 – November 01, 2021, 08:22:39 am

Quote from: dicksop – November 01, 2021, 01:50:32 am

Thanks for the explanation I take it the coach will not roll at all throughout the winter. Wheels are chocked and the pad is very very level

No worries. As already posted, the parking/emergency brake is RELEASED by air pressure. No air pressure= no move.

Re: Air brakes at 0 lbs in storage

Reply #6 – November 01, 2021, 08:31:48 am

Perfect! Again,thanks!

Re: Air brakes at 0 lbs in storage

Reply #7 – November 01, 2021, 12:01:36 pm

You could put blocks in place so the air bags don't compress flat. The bag failures are usually where the bags fold at the bottom. The rubber cracks and leaks right there.

With extended storage, some owners will put short blocks under the front and back, ground to suspension, just enough to take a few thousand pounds off the tires. Most tire manufactures recommend at least the max placarded pressures and even elevate pressures above that when in storage. Check with manufacturer.

Pierce

Re: Air brakes at 0 lbs in storage

Reply #8 – November 01, 2021, 12:15:45 pm

Thanks for asking the question. Probably some other folks on the forum that may need to know more about the air brake system. This link contains some good information. MotorCoach Brake Systems and Saftey Technology

Re: Air brakes at 0 lbs in storage

Reply #9 – November 02, 2021, 12:51:41 am

Pierce
I do have 10 inch safety stands (

in place for that exact purpose. After I raised the coach with the engine on I just installed stands, dumped air and turned everything off including the salesman. I am plugged into 15 amp so my inverter is keeping the house batteries charged and have a separate charger for my start bank. Going to have to get the air leaks checked out early spring to solve the 0 lbs pressure in the brakes though

Re: Air brakes at 0 lbs in storage

Reply #10 – November 02, 2021, 09:02:40 am

Quote from: dicksop – November 02, 2021, 12:51:41 am

Pierce
I do have 10 inch safety stands ( in place for that exact purpose. After I raised the coach with the engine on I just installed stands, dumped air and turned everything off including the salesman. I am plugged into 15 amp so my inverter is keeping the house batteries charged and have a separate charger for my start bank. Going to have to get the air leaks checked out early spring to solve the 0 lbs pressure in the brakes though

You might or might not have a issue. How long does it take for your brake tank go to 0 lbs?
Over a period of time mine will eventually go to 0 lbs. Air leak on your park brake side is not as
serious as a air leak on your brake side.

Re: Air brakes at 0 lbs in storage

Reply #11 – November 02, 2021, 09:49:11 am

Big al
Both of my front and rear service brake tanks leak down to 0 in about a week. As was stated I should be ok for the winter because the e brakes lock and will release when I fire up the coach. On the spring and bring the air pressure up above 60psi
Ps. Going to have someone investigate and repair in the spring

Re: Air brakes at 0 lbs in storage

Reply #12 – November 02, 2021, 10:11:46 am

I think down to zero in a week is going to be hard to beat. (sorry for the rhyme) That's as good as I've ever seen on ours.

Pierce

Re: Air brakes at 0 lbs in storage

Reply #13 – November 02, 2021, 10:15:23 am

Quote from: dicksop – November 02, 2021, 09:49:11 am

Big al
Both of my front and rear service brake tanks leak down to 0 in about a week. As was stated I should be ok for the winter because the e brakes lock and will release when I fire up the coach. On the spring and bring the air pressure up above 60psi
Ps. Going to have someone investigate and repair in the spring

Protection valves in the spring would be the first thing to replace.

Re: Air brakes at 0 lbs in storage

Reply #14 – November 02, 2021, 11:03:16 am

Quote from: craneman – November 02, 2021, 10:15:23 am

Protection valves in the spring would be the first thing to replace.

Agree...they are one of the most important safety components in the air system. Plus, replacing the protection valves first can help in chasing air leaks!

Once you know the protection valves are working properly, IF the coach owner has the opportunity to watch the gradual decline in pressure on the dash gauges (like visiting the coach every day to check the gauges), then they can gain a valuable clue to the location of the major system leaks. Two possible scenarios:

1. Starting at normal max system pressure, the dash gauges show a continuous decline, with roughly the same psi loss each day until the gauges get to 60 psi (or thereabouts), and then the gauges stop falling. They should hold at around 60 psi for several days before they start to fall again, at a much slower rate. In this case, the major air leaks are somewhere downstream of the protection valves.

2. Starting at normal max system pressure, the dash gauges show a continuous decline, with roughly the same psi loss each day until the gauges hit zero. In this case, the major air leaks are somewhere upstream of the protection valves. A study of the air system schematic may help with the search. Look for any device that is fed directly from the brake tanks (IE upstream of the protection valves). Also, in this scenario, it is very important to verify that the inlet check valves on the brake tanks are working correctly. If the inlet check valves leak, then pressure in the brake tanks can flow "backwards" to the wet tank. Then, if the inlet check valves on the wet tank fail, the pressure from the brake tanks could continue to escape all the way back to the air dryer, and the D2 governor.

Anyway, my point is that the protection valves, when working properly, divide the air system into roughly two "halves". Knowing which half of the system is leaking can help narrow down the search for leaks.

If you wish to test the inlet check valves on the brake tanks, try the procedure below:

1. Run engine until air compressor cut-out pressure is achieved. Shut off engine. The entire air system is now at the same pressure.

2. Check (record) the reading on both dash air pressure gauges (or both needles, if single dash gauge).

3. Open the water drain valve on the WET tank (see air system schematic), and allow pressure to bleed off to zero.
3a. What came out of drain valve? Dry air is good. Water, or oily grey "mud", or dry white powder is not so good. Time to service dryer.

4. Check (record) the reading on both dash air pressure gauges (needles).

5. If both dash gauges read the same pressure in step #2 and step #4, then the inlet check valves on the respective tanks are good.
Clarification: With "good" inlet check valves, the "front" and "rear" air tanks should not lose pressure when you drain the wet tank.

6. If either, or both, of the dash gauges lost pressure between step #2 and step #4, the inlet check valve on the respective tank is bad, and should be rebuilt or replaced.

Re: Air brakes at 0 lbs in storage

Reply #15 – November 02, 2021, 11:22:19 am

dicksop
truck driving schools offer air brake courses. in b.c they are
mandatory for driving a vehicle with air brakes. they are
not expensive, usually five weeknights for a couple of hours.
the course won't eliminate all the mysteries of the foretravel
air system, but will certainly give you a clear understanding
of your air brakes.

Re: Air brakes at 0 lbs in storage

Reply #16 – November 02, 2021, 11:57:52 am

Airbrake course and driver licence endorsement is needed in all of Canada if you are to drive a vehicle over 26,001 gvwr. It is commonly called a Z endorsement but in BC it shows as a class 15. You may never get stopped to check but if you have an accident and police look at your licence and do not see it you insurance could be void.
JohnH

Re: Air brakes at 0 lbs in storage

Reply #17 – November 02, 2021, 01:55:23 pm

The air brakes course is called a Q rating in Alberta. I took the course last year
Peter

Re: Air brakes at 0 lbs in storage

Reply #18 – November 02, 2021, 07:15:12 pm

How do the Canadian air brake rules affect US coach drivers in Canada?

Re: Air brakes at 0 lbs in storage

Reply #19 – November 02, 2021, 07:56:57 pm

Whatever the regs in your State is allowed in other States and Providences.

Re: Air brakes at 0 lbs in storage

Reply #20 – November 02, 2021, 11:18:32 pm

Quote from: oldguy – November 02, 2021, 07:56:57 pm

Whatever the regs in your State is allowed in other States and Providences.

Thank You

Re: Air brakes at 0 lbs in storage

Reply #21 – November 06, 2021, 09:41:17 am

All air brakes leak down. In the US it is no problem. They are allowed to leak down in less than a hour and still be ok.

Parking brakes do not need air to hold. Always chock the wheels when parked. Parking brakes might not hold on steep grades.

Re: Air brakes at 0 lbs in storage

Reply #22 – August 21, 2022, 01:05:44 am

I am visiting this topic of air brake and emergency park brakes again
I am currently at a site backed in where my back of the coach is sorta level and the front of the coach and wheels are sloped down. When I auto leveled it leveled out with the rear is the coach resting on the wheels and the front of the coach air bags raised to the max. Four red lights hitch many it is level. It never indicated excessive slope. I have chocks on each wheel ( heavy rubber). Now I am asking if my air brake (pulled out and activated of course) will hold the coach. ?? My air brakes will lower frozen 120/130 to just under 60 lbs in couple of days. Will they hold and will the spring brake come on to hold it as well. Do I have any worries...I would hate to wake up with the coach rolling right in to another coach...lol
X

Re: Air brakes at 0 lbs in storage

Reply #23 – August 21, 2022, 02:41:38 am

Peter,

My understanding is that when you pull the parking brake knob, the air pressure in the brake lines is immediately released and only the springs on the rear brake cans are applying the braking power. It does not matter at that point whether the air pressure gauges go down even to zero. It is the parking brake springs that are holding the coach.

Richard

Re: Air brakes at 0 lbs in storage

Reply #24 – August 21, 2022, 03:46:13 am

Thanks for the reassurance. I hope the rear brake cans can hold the weight at a slight angle. At 32000 lbs it all makes me nervous...

Affiliate Notice