Pac Brake ID, schematic, component locations and diagnosis

[J Alan]

5.9 DP Spartan Chassis

anyone here familiar?

I think the brand is BD Engine Brake

[Vycan]

I have some paperwork on this braking system in my coach. Will look at it this weekend.

[J Alan]

Originally Posted by Vycan

I have some paperwork on this braking system in my coach. Will look at it this weekend.

Any luck? I'd like to see what is located where or at least what the assemblies should look like that aren't completely obvious or even color coded.

I'm thinking it shouldn't be too terrible to diagnose.

[Tuco]

More than likely you have a bad vacuum cylinder. The o-rings in the original cylinder have probably rotted and is allowing vacuum to bypass the piston. This is what fixed my Pac Brake. If you give them a call they can help you get the new cylinder and instillation is easy. Make sure and get their high temp lube oil to keep it running smoothly. Hope this helps.

[J Alan]

The actuator cylinder may be tired and even looks serviceable. My initial assessment is there is an electrical control problem over the vacuum or high-pressure air that actuates it.

I'll call them although I'm doubtful they'll have specifics of where what is located on this particular rig.

[Tuco]

The system is not complicated. 12v is supplied to the master on/off switch. It then goes to the throttle switch (mounted above the gas peddle) and then heads to the solenoid on top of the engine. To test the solenoid remove the two hoses that go to the cylinder. then start the engine and find the port that has vacuum. Have someone engage the switch and if the vacuum switches ports the electrical system is fine. To find the solenoid trace the vacuum lines from the cylinder backwards (should be mounted on top of the engine).

gl

[Vycan]

Sorry, forgot. Out camping, will look through paperwork during the trip.

[J Alan]

I don't see any such solenoid on top of the engine but I'll take another stab at tracing what is there with your verbal description in mind.

I'd post pix, but, for whatever reason in Firefox, this forum appears only to accept web-hosted images although it does appear to allow browsing my pc for videos. Weird and I haven't tried uploading a video here yet.

Seems like I uploaded a picture somewhere here via the same browser and without running every single script this forum wants to run as I am doing now.

[J Alan]

Well let's see if the pix appear! Fired right up at 26 degrees this am with no block heater plugged in keeping it warm. That's good and I expected that with less than 70K miles on the rig.

[J Alan]

The pac brake actuator.

[J Alan]

Not sure what this is but, I'd fire everyone that went out of their way to prevent any reasonable man from glancing and seeing some form of color coding or at least something to make determination. It appears great pains were made to entangle and convolute things to that end.

[Tuco]

So this is a BD Power exhaust brake and not a Pac Brake. Here is what I found that might help. I found an installation pdf for BD exhaust brakes and their phone number. If you contact them and send your pictures a rep might be able to help diagnose things. (The last picture you posted appears to be the solenoid valve)

1-800-887-5030

http://www.catalograck.com/ImgVD/BDD...haustBrake.pdf

I hope this helps.

[J Alan]

Originally Posted by Tuco

So this is a BD Power exhaust brake and not a Pac Brake. Here is what I found that might help. I found an installation pdf for BD exhaust brakes and their phone number. If you contact them and send your pictures a rep might be able to help diagnose things. (The last picture you posted appears to be the solenoid valve)

1-800-887-5030

http://www.catalograck.com/ImgVD/BDD...haustBrake.pdf

I hope this helps.

Still digging and I'll study up on the Power Exhaust v Pac brake thing. This one appears to operate off high pressure air, is my guess.

After reading the destructions, it does confirm air and not vacuum.

I found another solenoid behind the P-pump. I'll attach pix of it and a better shot of the plate with its parts and pieces. I found no throttle switch and suspect the electronic 6 speed may have been programmed per the instructions.


Thanks for your patience and assistance.

I also found this which now has me hunting for the BD compressor and with an even better set of ideas regarding what else I should be hunting.

My assumption would have been that it used air from the two tanks onboard and not actually be free standing with regards to high-pressure control air.

http://pacbrake.com/wp-content/uploads/L5913.pdf

Digging further into the Spartan Chassis manual, it does indicate the system uses the chassis air supply and doesn't come with the BD compressor unit.

Just filling in the blanks for the future reference of others that may run across this.