Archived Pac Brake Problems

[skillsaw]

My Pac Brake seems to be running itself lately. It will not engage sometimes, & worse off... . It wil stay engaged at times bad enough that I have to pull over & force the piston back into the cannister. Any ideas from anyone?

-I have about 100k on this brake & it has been used a tun. 2 days ago, I removed the exhaust elbow with the unit on it & cleaned it very well, I also followed the solenoid cleaning procedures.

To no avail... ... Last night in the blazing New York snow storm, it got stuck on again forcing me to pull over, pop the hood & force the piston back down, in turn taking away prescious time that I could have been doing doughnuts.



Well, anyone have anything like this... any input

Thanks in advance



Erik

 

[Diesel Gunner]

I have a sneaking suspicion that your control solenoid may have some frozen moisture in it. I would suggest that you try just tapping the solenoid the next time that the brake acts up. Although there ain't much snow around here, I occasionally have mine stick after I wash down the engine. This is almost guaranteed to happen if I don't blow it out with compressed air and then drive the tuck a bit to dry it out.



Good Luck!

 

[Larry Willard]

I have had the same problem twice, the only thing that fixed it was to replace the vacuum cylinder. Before doing that I would clean the vacuum switch, and if your lucky that will fix it.

Larry

 

[skillsaw]

Larry,

The vacuum cylinder being the cylinder on the actual brake with the piston?

& The switch would be the solenoid with the 3 hoses & 1 breather right?



Thanks for the replies Gunner & Larry

 

[Stranger]

Had the same problem, fixed it.

Called Pac-Brake, the tech asked if the ambient air temp was cold outside. Yes, not as cold as NY though. He said a seal was compromised and the only way to fix was to buy a new cylinder.



Called Collins Fuel Injection, sometimes they have re-manufactured cylinders. After talking further I found that they re-man their by cleaning them. Also, I think it was Joe from Eureka on the TDR, who suggested I take the electric solenoid into my shop and take it "completely apart". Pac-Brake also told me how to test the solenoid without having to be in the seat. More on this later.



First thing, take the solenoid off and take it all apart. There's some REAL small parts in there so be careful. Squirt some Carb or Brake Cleaner in all the little passages and put it back together.



Next, what I did anyway, after it worked for a day, take off the elbow with the butterfly and take off both hoses, squirt alot of cleaner in both holes and work it back and forth, repeat twice, re-install. It's been working for a month w/no problems.



Here's a picture of how to test the solenoid. E-brake switch can be on or off. Engine has to be running. Use a small screwdriver or other pointy thing. If the brake doesn't go on, try cleaning the cylinder. Good Luck.

 

[TPCDrafting]

My valve was sticky for a long time, then one day it stuck on when approaching a stop light. Sure did get hot and smoky getting through the intersection so I could pull over. I only had a pocket knife on me so I had to cut hoses to get it off, I couldn't push open the cylinder. Once home I took apart the valve and found the solenoid was working fine, but the valve had some gunk in it. After flushing out with carb cleaner, it's worked flawlessly ever since. That was in November.

 

[Parks]

I think Pac Brake offers a cylinder rebuild kit.

 

[Larry Willard]

skilsaw

yes you have my references correct. When I took mine apart there was nothing dirty at all, so I just wiped all the parts with a clean rag and reassembled the valve, hence the cylinder replacement. Actually I have had to replace mine twice since 2000,seems to me there must be some manufacturing problems as many as I know have been replaced. Had no problems in the years I had one on my '96.

Larry

 

[jelag]

Several points you problem is one of these things or a combo of them... .



1 - the vacuum cylinder is a sealed unit... and is usually serviced by replacement... dirt can be cleaned out sometimes. . however a scored cylinder will always act up... . 100K miles... its paid for you might think about replacement... .



2 - the elbow can be cleaned and serviced... . heat, cold, rust all will take its toll... Pac Brake now offers a lube for the shaft and bushings... . its on the shelf at most distributors. . and is about 7-10 bucks. . don't remember off hand... but a few drops every 10-20K goes a long way to keeping this guy working...



3 - the solenoid can be serviced. . its got springs and small parts that can get out of your hand when you take it apart so be careful. . A small amout of silicon lube or vaseline will go a long way to keep this guy working... . wipe all parts first and apply only a drop or small dab of lube... We usually clean them once. . the second time we replace them... . Cheeper for the customer...



If you still have problems... were on the west coast and might be the oldest pac brake distributor in the country... . 7:30-5 PST Jim or Mark at 800-445-4696



Hope we've been of some help.....



Jim

 

[skillsaw]

Thanks to all!!



Jim - You're 100% right... . This brake has more than paid for itself!! It has saved me & my load through many pickles. It has paid for itself in brake service as well!! From placing the order, to installing the unit myself, this company has been nothing short of top notch!!



I (stupidly enough, & this is probably the reason for my problems here) have not touched this unit in any way for 100k - no clean, no lube, no service & until now, not 1 single problem... . That's incredible!!



Well, all replies have helped..... I think it might be the vacuum cylinder, but I'm going to try some better lube than the WD-40 I used on the little pin in the solenoid. It's worth one more try.



I'm new to TDR-

It's amazing that technology has caught up to us enough to be able to get help like this from complete strangers all over the country. (don't forget I'm from NY) It makes me feel good to know that there's still people like me who will pull over to help a vehicle in need!! It's been getting worse & worse in tha past years seeing all these cars go by me while I'm dead on the side of the road with another dead lift pump.



THANKS TO ALL!!!!



I'll let you all know how this goes!!