air pressure on 1972 silver eagle

ronnie32567 · December 02, 2011, 04:50:49 PM

I just bought a 72 silver eagle conversion bus, it has been sitting for several yrs and I thought the brake shoes were stuck to the drum. But I think the parking brake won't release, the brake light on the dash is still on when I try to release brake. Air gauge reads about 67 psi, is this normal? the parking brake button says to release brake at 100 psi, there is no air leaks that I can hear. Anybody have any ideas? Thanks for reading this HELP!!

robertglines1 · December 02, 2011, 05:03:34 PM

air should go to aprox 120 max before stopping.

ronnie32567 · December 02, 2011, 05:06:27 PM

air goes to the 67 mark pretty quick and just stops no matter how long you run the engine, but I don't hear any air leaks. Is there an adjustment to the air pump or is it bad?

robertglines1 · December 02, 2011, 05:21:56 PM

Things could just be stuck (if your lucky ) from sitting. Make sure all tank drain valves are closed. Ck supply side to your air compressor for blockage(not very likely) Broken lines---leaking fittings---brake diaphragms..combinations of all or compressor. If you ave a portable compressor see if your system will hold air otherwise. sitting is often worse enemy. Bob

robertglines1 · December 02, 2011, 05:27:01 PM

add stuck Governor to that. maybe a slight tap with hammer would loosen it up.

robertglines1 · December 02, 2011, 05:34:33 PM

Ronnie: up top search line put in not building air pressure and hit search. Mike refers to governer also. Bob

luvrbus · December 02, 2011, 05:37:17 PM

Stuck governor on the compressor or the AD2 air dryer on the drivers side in the engine compartment needs servicing disconnect the 1/4 inch tubing on the bottom of the dryer it should start pumping.

That model of Eagle has DD3 brakes it will take over a 100 lbs to release the parking brakes if you are lucky, you may have a job on your hands lol

good luck

robertglines1 · December 02, 2011, 05:46:01 PM

Hope it ends up simple. Happy bussin! Clifford(luvrbus) is the Eagle guy!

ronnie32567 · December 02, 2011, 05:52:10 PM

thanks for the advice, I'll try everything tommorrow

buswarrior · December 02, 2011, 06:12:16 PM

You are leaking air.

Period.

There are all sorts of valves in the system to explain why you get to 67 lbs and can't find the leak when you shut off the engine. That comes later.

You will need a set of maintenance manuals for the coach, start looking online now.

You will benefit from a decent oil-filled compressor as an accessory for the coach, get it now to help you find leaks without the roar of the engine drowning them out.

Get a spray bottle and some dish soap and make up some soapy water to spray around. When you find the leaks, you will need to replace the offending components.

Check the exhausts on all valves that have them. Check the lines and hoses.

Once you can get it to go to 120 lbs or so, and stop there and sit for awhile, then we can move on to the next challenge.

happy coaching!
buswarrior

Bill 340 · December 02, 2011, 06:54:28 PM

our old eagle did that occasionally, then when least needed a problem, it would not build over 70 lb. turned out to be the govenor, $22.00 for a new one, that anyone can replace and it was fine to go.

Flatspot · December 02, 2011, 06:55:16 PM

I agree that if the compressor is pumping, you have an air leak. Clifford's advice will verify that. I also agree a good a good shop air compressor along with manuals specific to your coach should go in your tool box.
That said, in addition to other suggestions, something to look at is the discharge line and fittings on the bus air compressor to the drier and the wet tank. If you have an air leak between the compressor discharge and check valve you won't find it building air pressure in your system with an external air source. This can be done with the engine running. Spray soapy water on the discharge line to make sure it isn't leaking through the jacket.
Make sure the windshield wipers aren't turned on too.
Keep in mind it is a process and it may be more than one leak and just because you found one doesn't mean that there aren't more.
Clifford means that you need to make a 100+ psig brake application with the foot valve, after you push in the dash valve, to release the parking brakes on a DD3 system which is what your coach is equipped with.
Good luck and have fun.

Larry

ronnie32567 · December 02, 2011, 07:00:30 PM

I have a big compressor I can plug into the generator, can I plug into the air port behind the front bumper. I have'nt looked at the port yey, does it have a quick connect or do you have to use bushings to get the right connection. Can I run the portable compressor on the front port at the same time the engine is running the coach pump to hopefully make enough air to get the coach home, have about 10 miles to get home.

robertglines1 · December 02, 2011, 07:04:40 PM

Where you at??? could be a busnut close by to help. Bob

luvrbus · December 02, 2011, 07:13:35 PM

Could have a quick connect but most have a plug from the factory where you can screw a quick coupling into and you can run the portable with the engine running won't hurt a thing

Check the pressure with the portable without the engine running if it airs it up to 120 lbs you have minor problems and not many leaks

good luck