Noise when depressing brake pedal.

[Irishman1]

2005 monarch 30ppd with the ford f53 chassis. Want to know if this is normal. When the mh is running and in park there is a loud buzzing noise when you push the brake pedal. Maybe a warning buzzer? Goes away when you move the gear select out of park or take you foot off pedal. I’ll look for a speaker or buzzer under the dash later

[tmw188]

You should probably go over to the Ford Chassis group on IRv2 they would probably be able to help you.

[Tom Cherry]

There were some “unusual” circuits around that time.  A Workhorse model would “think” that the parking brake was on, when you hit a bump and “jiggled” the seemingly rigid switch mount of the plunger….disconcerting to say the least…hit another bump….go off.

I would try to find a Ford HD truck shop.  They have the prints.  The brake pedal circuit thinks something is WRONG.  For example, is there a fluid level switch in the master cylinder?  WH had an air over hydraulic system and if the level in the HD brake reservoir got low….it warned you….check the fluid level.  If full, is there a sensor or switch on it?  But, without the chassis print….it is a crap shoot…..

OF COURSE….if you ask Google….nicely and with the right phrasing…..

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28819357/print/true.cfm#:~:text=If the engine isn't,F-53 chassis do it.

May be your issue.  NOW….is the “buzzing” you hear NORMAL….only a Ford HD Tech can tell you….one would NOT want a motor to fail that is critical to the brakes….

Let us know…..

[dl_racing427]

Is this a hydroboost brake system?
I've driven a few trucks with those, that could make a buzzing sound if a little air got into the power steering/brake boost system.

Does it do it if you push the brakes with the ignition switch in the run position, but the engine not running?

[Irishman1]

On 10/20/2023 at 7:19 PM, dl_racing427 said:

Is this a hydroboost brake system?
I've driven a few trucks with those, that could make a buzzing sound if a little air got into the power steering/brake boost system.

Does it do it if you push the brakes with the ignition switch in the run position, but the engine not running?

I’ll check, it definitely sounds like a warning buzzer that goes away as soon as the pedal is released or you put the gear selector out of park. I haven’t checked it it does it with just the key in and not running tho

Just now, Irishman1 said:

I’ll check, it definitely sounds like a warning buzzer that goes away as soon as the pedal is released or you put the gear selector out of park. I haven’t checked it it does it with just the key in and not running tho

 

On 10/19/2023 at 1:33 PM, Tom Cherry said:

There were some “unusual” circuits around that time.  A Workhorse model would “think” that the parking brake was on, when you hit a bump and “jiggled” the seemingly rigid switch mount of the plunger….disconcerting to say the least…hit another bump….go off.

I would try to find a Ford HD truck shop.  They have the prints.  The brake pedal circuit thinks something is WRONG.  For example, is there a fluid level switch in the master cylinder?  WH had an air over hydraulic system and if the level in the HD brake reservoir got low….it warned you….check the fluid level.  If full, is there a sensor or switch on it?  But, without the chassis print….it is a crap shoot…..

OF COURSE….if you ask Google….nicely and with the right phrasing…..

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28819357/print/true.cfm#:~:text=If the engine isn't,F-53 chassis do it.

May be your issue.  NOW….is the “buzzing” you hear NORMAL….only a Ford HD Tech can tell you….one would NOT want a motor to fail that is critical to the brakes….

Let us know…..

That sounds like what’s going on with mine, an electric buzzer when the keys is turned on and the brake pedal is pushed until it’s started, then it hoes off. Thanks