PacBrake Instalation

[TBusclas]

I am installing my brake today and need some advice if anyone can help. My truck already has air on board, my understanding from the company I purchased it from was that I would not have to hook this up through the fifty pin connector. The instructions from PacBrake say specifically "vehicles not using ecm bypass/vehicle has an existing air source" yet the diagram that goes with this page shows the white wire from the shifter switch going in on pin 39 and the black wire to the relay going out on pin 42. My question, can I just hook my switch straight to a fused power source or do I need to follow PacBrakes diagram and if so what is the purpose of running through the fifty pin connector. Thanks

 

[Prairie Dog]

It needs to have something to tell it when to engage, that's what the fifty pin connection does. Basically it's a "low" or negative signal to a relay on the PB that comes on any time the throttle has been at zero for 2 seconds (to keep the brake coming on every time you shift). It then allows air to flow to the solenoid on the brake. It's really a slick system and can even throw a code if the PB relay sticks on.

It's really not hard at all. Just make sure you have both batteries disconnected.



There's also a micro switch you can buy to cob onto the throttle but it won't have the 2 second delay that you need.

 

[TBusclas]

I see, just wasn't getting through my thick head what was happening. When switch is "on" on the shifter the system is activated and engages automatically when throttle is reduced for two seconds or more. Now going back and doing some more reading I might need the clutch deactivation switch also. Thanks

 

[Motorhead]

I don't have the clutch deactivation switch on my '07, 5. 9 6 speed. Just the RED push-pull switch. works PERFECTLY. I couldn't be happier with my Pacbrake!

 

[jelag]

After selling and installing many of these over the years I suggest you connect to the ECM and try it that way... . the computer will turn on the brake to warm the engine on a cold day... will turn on the brake with the cruise control running when you go down hill and of course will cycle as needed as you go down hill.....

The switch, will allow you to turn off the automatic function if you wish... I never turn mine off... ...

As you push the connectors into the ECM... . first pull the connector off the ECM and make sure that the supplied wires... snap into place... its the most common problem with the brake not working... these connections didn't snap into place...

Take the inner fender off the passenger side of the truck... . 6 or 8 screws... you don't need to remove the wheel...

Once the brake is installed... run the brake a hundred miles and re-tighten the clamps on the brake. . this will be the only time you need to do it... .

 

[Prairie Dog]

You don't need a switch for the clutch - that's what the two second delay is for.

 

[Shadrach]

I installed mine myself on my 03 without any glitches and love it. David

 

[Prairie Dog]

I don't have the clutch deactivation switch on my '07, 5. 9 6 speed. Just the RED push-pull switch. works PERFECTLY. I couldn't be happier with my Pacbrake!

Where do you get one of those switches?

Thanks,
Scott

 

[jelag]

Your pacbrake distributor should have in stock a shifter switch... . its mounts to the gear shift lever and is easy to trip with a finger... . Mine are on the right and I trip them with my little pinky.....

 

[Motorhead]

Here is one on fleabay: http://www.ebay.com/itm/GM-2-SPEED-...Parts_Accessories&hash=item19de6fa8e5&vxp=mtr

 

[Prairie Dog]

Thanks MH.

 

[MAshley]

Without the clutch sensor the brake can be engaged while the clutch is in, I don't have one but you need to be aware of it so your not causing undue strain on the clutch between shifts, slight press on the skinny pedal eliminates any unwanted braking and or you can flip the switch.



Also that wire in the ECM is GROUND not power, at least in my setup. Maybe it doesn't matter but that is what I recall from 5+ years ago. I have a ground running to my switch to the ECM and then out of the ECM to a relay to control the switch on the air valve. In any case you will love the EB





One last thing when the truck is warming up with the EB on once warm it will kick off the EB. Oo.

 

[TBusclas]

Thanks for all the responses, everything installed and works well, I went ahead and ordered the clutch switch, I do have one problem, I already had on board air. The compressor comes on at 175 and kicks off at 200. My solenoid valve works fine till about 185, after that it hangs and you have to get out and tap it for it to release, below 180 it works flawlessly. I am going to town and get some cleaner and try flushing it out backwards with some compressed air while actuating it. If this doesn't help guess I will contact Pacbrake Monday and see what they say. Hoping to hear from someone that is running this kind of air pressure though. Thanks to all

 

[jwduke]

Not to hijack this thread, but will the PacBrake work on a '04. 5 with a automatic? I understand the "brain" isn't big enough to run a engine brake.

 

[TBusclas]

Just to report back, the Pacbrake supplied solenoid will not release above 180 psi. Any thing below that and it worked flawlessly. The reason my pressures are so high is I had already installed on board air and used a system from Viar, one of their bigger compressors and a 2. 5 gal. tank. It cycled on and off at 175/200 psi. I installed a miniature regulator between my supply and the solenoid and set it at 130 and now no problems at all.