1991 Midliner CS300 Air Leak

[MTMACK50]

Hi Folks - 1991 Mack Midliner CS300

First the PARK BRAKE indicator light on the dash stays on even when the air builds up and releases the parking brake.

I replaced a crusty old valve near the air tank with this SEE ATTACHED PICTURE 1

This new valve didnt fix the dash light stay on problem.

Also I get a air leaking sound from the (2) identical WABCO valve type parts located under the hood on the firewall.

When I tap the valve housing lightly with a hammer, the leak stops. SEE ATTACHED PICTURE 2

The only writing on these 2 identical valves is the word WABCO .

Was thinking I could rebuild these valves with a kit but no part #'s found.

Any help you folks could give on either of my two issues posted here would be greatly appreciated.

Other than these 2 issues, this Mack Midliner has treated me very well since 2002 when I got it.

Thanks

[Redneck trucker]

On 7/21/2015 at 4:06 PM, MTMACK50 said:

Hi Folks - 1991 Mack Midliner CS300

First the PARK BRAKE indicator light on the dash stays on even when the air builds up and releases the parking brake.

I replaced a crusty old valve near the air tank with this SEE ATTACHED PICTURE 1

This new valve didnt fix the dash light stay on problem.

Also I get a air leaking sound from the (2) identical WABCO valve type parts located under the hood on the firewall.

When I tap the valve housing lightly with a hammer, the leak stops. SEE ATTACHED PICTURE 2

The only writing on these 2 identical valves is the word WABCO .

Was thinking I could rebuild these valves with a kit but no part #'s found.

Any help you folks could give on either of my two issues posted here would be greatly appreciated.

Other than these 2 issues, this Mack Midliner has treated me very well since 2002 when I got it.

Thanks

If u take off the in line an squirter something like wd40 in it just 3 or 3 quick squirts and put line back on an air it up,do both valves at same time,oring inside is dry,

 

On 7/21/2015 at 4:06 PM, MTMACK50 said:

Hi Folks - 1991 Mack Midliner CS300

First the PARK BRAKE indicator light on the dash stays on even when the air builds up and releases the parking brake.

I replaced a crusty old valve near the air tank with this SEE ATTACHED PICTURE 1

This new valve didnt fix the dash light stay on problem.

Also I get a air leaking sound from the (2) identical WABCO valve type parts located under the hood on the firewall.

When I tap the valve housing lightly with a hammer, the leak stops. SEE ATTACHED PICTURE 2

The only writing on these 2 identical valves is the word WABCO .

Was thinking I could rebuild these valves with a kit but no part #'s found.

Any help you folks could give on either of my two issues posted here would be greatly appreciated.

Other than these 2 issues, this Mack Midliner has treated me very well since 2002 when I got it.

Thanks

If drain air pressure off an take the in line off an put a couple of squirts of something like wd40 in it an replace air line,do both valves at same time,an then build up air ,there's an oring inside valve, if truck sit a long time they get dry an want fully seal,,I have also taken the out side air hose off the air compressor an put a whole bottle of rubbing alcohol in the line an reconnected it an built up air pressure to push it though complete brake systems to help clean an dry out any moisture in lines,tanks,brake chambers,etc, 

[Joey Mack]

it is good of you to offer some help, but that post is 7 years old..     Welcome to the Dog Pound....   jojo