Need exhaust brake help.

[Coalsmoke]

I have an older PacBrake and the throttle off switch that attaches to a plate on the timing case (I think) had to be replaced as it was worn out. It is situated so that when the throttle is off, the linkage is full forward and it hits this switch, which allows the ex. brake to be activated. This makes sure that the ex. brake is never left on while accelerating. As mentioned above, I had to replace this switch, and the new switch is somewhat stiffer than the old worn-out one, so that the brake will not engage until the RPM's drop to around 1000rpms. So, I thought that I could maybe add a second spring helping the throttle arm and linkage go forward with more force (when you let your foot off the throttle) and trigger the switch. Would there be any ill effects of adding this spring? I don't want to break anything out of ignorance.



many TIA,

Stephan

 

[Joe G.]

You have the old style switch. Get hold of Pacbrake and get the newer style that mounts in the cab under the throttle pedal. I don't know if they still stock them as a kit so the conversion from the old style to the new is easier. The old style micro switch is too stiff. It will eventually creep and quit working so you have to readjust. The old style also requires a helper spring for the throttle spring. That just makes your foot more tired. With the new style you don't need the helper spring. It's been a few years since I changed mine over, but I think the kit was available for no charge when I did mine.



If you have the new switch and it is stiff then it is mounted wrong (don't ask me how I know). It should have a long spring type lever on it that goes under the throttle pedal linkage. It takes very little pressure on the side of the spring lever to work the switch.

 

[Coalsmoke]

Yup, they still have the new style, but I thought I would save 30 bucks and go with the old style does this conversion kit have the new wiring as well, or am I putting that together myself?

 

[Joe G.]

The old style is a PITA because the mounting screws keep slipping. Then the brake does not work until you adjust the switch again.



The kit has the necessary wires to make the switch from the old to the new.

 

[Coalsmoke]

OK, thanks for the advice. I'll go pick one up asap

 

[Desperado]

I hooked a second switch up so that when I push the clutch in it cuts the brake out works great at stop lights, never have to shut off the master switch.

 

[Coalsmoke]

Yeah, I was wonderng about that. That way when its time to go, both hands can stay on the wheel. That's a good idea.

 

[Coalsmoke]

Alright, replaced the switch with the newer style as suggested, (PacBrake people were very helpful) and now it actually works above 1100RPM Oo. I'm going to go find a big hill and give it a worthy test, but it looks like this was deffinately the right way to go.



Thanks guys

 

[Joe G.]

If you find that it does not work above some RPM then adjust the switch a little. Mine would not work above 2000 for a while, then I discovered that if I adjusted the switch so it was not quite so close to off on the pedal then it would work above 2000. I think the governor affects the linkage a little bit at high RPM so it's the same as if the pedal was pressed a little bit.