pulltilbroke

OK, So the dually had an exhaust brake on it when I got it but the brake valve was stuck and hadn't worked in some time And I pulled everything off when I did the front clip and the DE 4" . Anywho I think were gonna put it back on now so last night i got the valve freed up and its been soaking in oil over night.

Just kinda wondering is there a special lube that needs to be applied to the valve itself or if I just gotta use it to keep it freed up?

jimbo486

I say just use it often so that carbon doesn't have much of a chance to build up on it and cause it to seize again.

Alec

In the old days, they used to recommend lubricating the bushings with penetrating oil at every oil change . . . but ideally you would be able to get some sort of graphite or molybdenum to penetrate into the bushing, as any oil is going to burn away.

j_martin

PacBrake has a special lube they sell for it. They also recommend operating it occasionally to keep it free.

It's called:

PACBAKE
EXHAUST BRAKE
Maintenance
Synthetic Lubricant

The lube goes everywhere......on the shaft, and in the cylinder.

You can order it directly from them.

d22019

The Pacbrake stuff works great. Using the brake frequently helps keep it from sticking too.

pulltilbroke

I know if its on the truck it will get used all the time.

jbawden

Speaking of maintenance, is there anything to the pump that needs to be lubed or adjusted? I have a Pacbrake on my '93 and the pump runs for about a second, then cycles on-off-on-off and eventually closes the brake. Works great once closed but I'm assuming the pump is supposed to run until closed, then cycle to maintain pressure? I jumpered the switch (looks like an oil pressure sending unit) and the pump ran continuously once activated and quickly closed the valve. I assume that is a pressure switch? Anyone have any details on getting a new one or what the specs are?

j_martin

That's not the standard brake on that truck, so get your label data before you call.

They're very helpful at the 800 number. They'll try to get you to go to a dealer to get parts, but usually it's easier to just insist on paying full retail and get it shipped right out.

http://www.pacbrake.com/index.php?page=customer-support

jbawden

Not sure how you gathered that from what I told you, but I will give them a call. The part I think is bad is pictured below, red wire coming out. PO (father in law) said it used to run, then cycle once closed.

crazy clem

dont the original pac brakes work off the vacum pump?

j_martin

Yep. I'm sure mine was installed soon after the truck was bought. It's a throttle (closed) switch, a solenoid valve, and a vacuum operated brake valve.

I'm sure the air version works fine also, but just be sure you tell them which one it is.

On my to do list is a small circuit board with logic to sense the state of OD, and turn it off if it's on when you throw the toggle switch for the exhaust brake, and also turn it on if it's off when you turn off the exhaust brake. Best guess is it's a one chip deal.

jbawden

Thanks for the info. As reported, PacBrake customer service is the best. The CSR Chris troubleshot...troubleshooted :-) over the phone and turns out the pressure switch was bad. I guess my brake is a 94+ that has been retrofit onto my truck, it works amazing. Also, for anyone the comes across this thread, there is nothing in the pump that needs maintenance, just the "super lube" on the valve and related actuating hardware.