Frozen PacBrake butterfly

[rwilliams4]

I have a PacBrake on my 97 3500. I have checked the vacuum and the cylinder and both work, but the butterfly , at the exit of the turbo, is frozen. I used Liquid Wrench and wD-40 but I can't budge it. I guess I will have to remove the casting from the turbo exit and the exhaust pipe. The exhaust pipe bolts are unbelieveably tight. I wish I could free the butterfly without removing the casting. Any suggestions? For the life of me, I can't free the flange bolts at the lower end of the casting. I may have to take it to the local mechanic to have it done. I would appreciate any comments on this.

 

[Joe G.]

You will probably have to take the whole thing apart to clean out the carbon buildup so it has to come off. If you don't use it a lot it will eventually do this. Another thing you should clean once in a while is the solenoid/vacuum valve. That's the little gadget that is attached to the back of the air horn. It has a little piston in it that carbon builds up on. It doesn't take much for the thing to stick with brake closed. This is kind of dramatic. No power, EGT gets very high, and it smokes like a forest fire.

 

[rwilliams4]

Cleaned solenoid

Joe:

I did clean the solenoid. I dropped the little bllack spacer and it was impossible to find. I called PacBrake and they sent me a little package of spare parts for the solenoid (including the elusive spacer). They sure are nice people to deal with. I have had mine on my truck for over four years now so I guess it does have a carbon buildup, as you say. It's going to be a bear to remove, though. I wonder how I can prevent this from happening again. Thanks for the response.

 

[Joe G.]

I turn mine on everytime I start the truck. It operates whenever my foot lifts so that keeps the carbon from building up. The Dodge dealer warned me about that when I bought the brake. I've had mine since '95 and the only problem was the solenoid sticking. That REALLY smogged up Broadway here in Eureka! No tailgaters when that happened. I took the solenoid off the truck to work on it so anything I dropped stayed on my work bench.

 

[Doc Tinker]

rwilliams4,



If you have a propane torch, you may be able to warm up the flange enough to break the bolts loose. I use MAP gas, which comes in a bottle, like the propane, it gets a lot hotter than propane and would work better.



Your alternative is to take it to a shop and they will heat it with an oxy/acetylene torch to remove the bolts.



You might try lugging the truck up a few hills, to get it good and hot and see if they will break loose then. Worth a try. .



Doc

 

[DRR-24V]

R Williams,

Can't you disconnect the actuator rod, flood with penetrating oil and then tap on the butterfly arm in both directions till it frees up?

I would flood pen. oil on it in any case, as it will make it easier for the dealer to fix.

 

[EMDDIESEL]

If i rember correctly, they have since upgraded the design and coated the valve to keep this from happening. Maybe you can get an upgrade kit for yours to prevent the same thing from happening.

 

[rwilliams4]

Appreciate the replies!

Great information from everyone. Thanks a lot!

 

[Archive]

EMD is correct about the new PacBrakes... they have a special coating to help prevent this. I read that from Bill K. , I believe.



I use my e brake every time I drive my truck. Not only should this prevent it from ever sticking, they are just plain nice to use!