M923A1 air buzzer problem

[Jericho]

hey 74 no Biggie , was looking in deuce side then spotted a problem, Ill help out I thought , gave half a Tech manual of info , next day realized it was in the hum vee forum, used to break a lot of em, didnt fix many , SoThanks for jumping in with us, its all valuable info and it all comes out in the wash ( I never looked in the beginning to notice it was an A! I have an A2 , a little different ) I get more gee whiz your right info here than reading the T.O. anyway All stand up fellas!

 

[Randyw]

Thanks again 98, I will replace the low air sensors and also the PPV. I did just go outside and bleed the air and I had no moisture or water in the system.

 

[Jericho]

So does the A1 only have two or is it the same as the A2 , three. primary secondary and spring brake

 

[98G]

Thanks again 98, I will replace the low air sensors and also the PPV. I did just go outside and bleed the air and I had no moisture or water in the system.

Moisture is there, just not at the purge valves.

Be sure and post the eventual outcome - it's entirely possible I'm wrong, and if so I want to learn from it.

 

[Randyw]

Moisture is there, just not at the purge valves.

Be sure and post the eventual outcome - it's entirely possible I'm wrong, and if so I want to learn from it.

Is there another way to bleed the moisture off besides using the purge valves? Thanks for all your help and I will for sure post the outcome hopefully I find this problem soon.

 

[Randyw]

So does the A1 only have two or is it the same as the A2 , three. primary secondary and spring brake

Jericho, I just looked a little bit ago and there seem to be three. Primary, Secondary, and spring break. Are all these sensors the same part number?

 

[98G]

So does the A1 only have two or is it the same as the A2 , three. primary secondary and spring brake

3 total. Same on A0 A1 and A2.

 

[74M35A2]

 

[Jericho]

I quite agree. Read them all the time. Never really paid attention to the A1section. But thought configuration of brakes was the same except for ABS mod. Curious now will have to look when I get time. About 2057

 

[Jericho]

Yes they are all the same I think Swamp has the most experience with them and has the scoop on silencing the dam buzzer Check the internet. Look hard prices vary Widely. From $42 to 300 per switch

 

[Jericho]

Air dryer is about the lowest point in system. I opened all the tank drains and pressure fed a little air system lube from Napa into my tanks. Just a misted spray with an air chuck chuck my truck had low miles lots of at ease time and no one rvet drained the tanks. Don't remember the name of the stuff but it was made for spray misting air systems and sold at Napa. Did. Solve two sticky valve problems in about a week

 

[Randyw]

Air dryer is about the lowest point in system. I opened all the tank drains and pressure fed a little air system lube from Napa into my tanks. Just a misted spray with an air chuck chuck my truck had low miles lots of at ease time and no one rvet drained the tanks. Don't remember the name of the stuff but it was made for spray misting air systems and sold at Napa. Did. Solve two sticky valve problems in about a week

Thanks Jericho!

 

[Randyw]

Update on alarm problem:

So I drained all the air out of the system and changed all the low pressure air switches. I also changed the PPV as well. When I drained the air out of the system there was no moisture or water.

I fired the truck up with no air pressure in the system and had the emergency break off. When the truck started the buzzer and low air pressure light was on. When the air pressure reached 85-90 on the gauge both the light and alarm went off. So the truck idled for approximately 50 min and then the buzzer alarm came on. The only consistent thing in this whole deal is the buzzer alarm comes on every time the engine reaches 140 degrees on the gauge. I can wake up the next day with a cold truck and start it with no alarm at all once the air pressure builds up to 90 psi. But every time the truck hits 140 degrees on the temp gauge its like clock work, the buzzer comes on.

I have checked all the grounds I could find but still no change. Does anyone have any suggestions? I have not changed the alarm box itself but I have looked at it and it looks like it was replaced not to long ago. I am out of ideas on this one!

 

[Jericho]

I don't know of any tie into the temp sensor in the engine and the low air pressure system , Let me think on it for a couple of days , BUT , have you looked at the micro switch in the actual emergency brake handle, Its under the three way air switch and inside the mechanism of the brake handle . Its a spring steel arch spring with a set of contacts set in a rubber membrane , Two wires go thru the penertration where the brake handle goes thru the floor , one goes to ground the other to a tie in under the floor. If you were to leave the handle UP (sic applied) the buzzer sounding and apply force to the side of the handle , pushing it toward the passenger seat. does the buzzer go off or become intermmitant

 

[sandcobra164]

I've got a similar problem. Mine flashes "Air Low" and "Parking Brake On" and buzzes. When I first got the truck, never had those issues. When it first happened, I remembered a thread on SS to check the wires going to the parking brake switch next to the handle. Tugged the wires slightly and problem solved for that trip. Did it a few times after as well and same solution. Now it doesn't matter how I bump or tug the wires, lights flash and buzzer sounds. I know the problem is likely a chaffed wire touching ground but I did the unthinkable. I've got a trip coming up soon so I removed the bulbs and taped the little hole on the buzzer. To be clear about my intentions, I broke my foot two weeks ago and cannot chase down a chaffed wire at the moment. That would be the smart thing to do. I drive the truck with a keen eye on the gauges to ensure I have air pressure. I know my truck cannot drive through the spring brakes as verified through routine maintenance checks. My backyard troubleshooting has led me to rebuild the top hat of the compressor, replace and adjust the governor, upgrade to the newer style air dryer Suprman sells, and finally replace the PPV valve. I'm confident in my trucks compressed air system being ready to supply air for my brakes. I'm also confident that if I have no air, the truck won't roll. I've also been through the axles and brakes. Only make an informed decision and if you decide to do as I did, know that you best stay on top of your gauges and feel confident that you know the rest of the braking system is up to standard. I'll fix the wires on mine when my foot heals!

 

[Randyw]

I don't know of any tie into the temp sensor in the engine and the low air pressure system , Let me think on it for a couple of days , BUT , have you looked at the micro switch in the actual emergency brake handle, Its under the three way air switch and inside the mechanism of the brake handle . Its a spring steel arch spring with a set of contacts set in a rubber membrane , Two wires go thru the penertration where the brake handle goes thru the floor , one goes to ground the other to a tie in under the floor. If you were to leave the handle UP (sic applied) the buzzer sounding and apply force to the side of the handle , pushing it toward the passenger seat. does the buzzer go off or become intermmitant

I have checked the switch in the emergency brake handle and the wires. All seems well but I have not pull the brake and applied pressure to the side of the handle. I will try this tomorrow and let you know. Thanks!

 

[Jericho]

the ground wire is connected to the floor of the cab directly under the handle , you need to crawl under to trace it back.