Brake Issue

[Seabass69]

2004 HR scepter, the front brakes like to lock up hard if you have to use ter brakes very hard. dry ground or wet they will lock and slide quickly.... any ideas on what to look at first? Maybe just as simple as new pads on rotors on the front?

Thanks

[Ray_IN]

Seabass69 wrote:

Ray,IN wrote:
Check for water in tanks, if water is allowed to remain in tanks it can get into the braking system, which gets expensive to repair.
When was the air dryer filter last replaced?

I bought it 2021 and replaced it then, may need to again.. thanks

For trucks with air brakes the dryer filter must be replaced annually, but for our infrequent MH use every 5 years is adequate.

[Seabass69]

oldave wrote:
Many/most brake systems have a proportioning valve that regulates the pressure front to back. I can't say for sure you have one but you probably do.
Your symptom sounds like the rear brakes are not getting their share of air pressure IMHO.
Google & see what they look like.

thanks

[Seabass69]

Stim wrote:
Could be a defective relay valve not releasing or operating slowly. ??
Maybe a kinked air hose. ??
With MH stopped, press hard on brake peddle then release and listen for the air to exhaust. Is it instant or time release?
I've worked on hundreds of air brakes on semi's but got out of it before disc came out so I'm guessing a lot.
It should have standard generic air brake parts available at large truck parts stores.

it sounds normal to me but I will look into that, thanks

[Seabass69]

Ray,IN wrote:
Check for water in tanks, if water is allowed to remain in tanks it can get into the braking system, which gets expensive to repair.
When was the air dryer filter last replaced?

I bought it 2021 and replaced it then, may need to again.. thanks

[oldave]

Many/most brake systems have a proportioning valve that regulates the pressure front to back. I can't say for sure you have one but you probably do.
Your symptom sounds like the rear brakes are not getting their share of air pressure IMHO.
Google & see what they look like.

[Ray_IN]

Check for water in tanks, if water is allowed to remain in tanks it can get into the braking system, which gets expensive to repair.
When was the air dryer filter last replaced?

[Stim]

Could be a defective relay valve not releasing or operating slowly. ??
Maybe a kinked air hose. ??
With MH stopped, press hard on brake peddle then release and listen for the air to exhaust. Is it instant or time release?
I've worked on hundreds of air brakes on semi's but got out of it before disc came out so I'm guessing a lot.
It should have standard generic air brake parts available at large truck parts stores.

[Seabass69]

oldave wrote:
Are you sure it's disc? My 03 Monaco has drum brakes all around & yours is a Monaco too.

it is disk, air pod on the caliper itself

[Seabass69]

enblethen wrote:
Need make sure that the air gets drained from tank. Caliper pistons could be rusted.
How long has it been sitting?

it doesnt sit much, just a little over the winter but this problem was there last year

[oldave]

Are you sure it's disc? My 03 Monaco has drum brakes all around & yours is a Monaco too.

[enblethen]

Need make sure that the air gets drained from tank. Caliper pistons could be rusted.
How long has it been sitting?

[wolfe10]

And, if floating caliper disk brakes, check that the pins (that the caliper floats on) are clean and lubed.

Pretty easy for dirt, rust, etc to not allow the "lazy pad" to pull away from the disk.


Since it is "air brakes for sure", no worries about changing brake fluid.

[enblethen]

I would check with your local NAPA

[Seabass69]

Roadmaster I believe