Archived Engine REAL sluggish

[johnmoore]

Guess I screwed something up today. Just got back from a 500 mile trip the other day. Today I look under the hood and see it's all crudy from road salt. I figure since it's a nice day (50-60) out why not wash it off. So I do and after I'm done I thought it might be a good idea to start it up and let the engine heat burn off the water. While it's idleing I turned on the PacBrake. After about 15 min. I get in to shut if off, my post turbo EGT is about 375 so I flip the switch off but don't notice the usual change in exhaust sound. Keeping an eye on the guage I see that the EGT isn't dropping any. So I decide to take a trip down the road and see if that will unstick it. Lo and behold I find I can hardly drive up a little 60 foot hill! Drop down into first gear and the black smoke is just pouring out the pipe. I look at my EGT gauge and it's showing 900!! I've never seen it get above 800 before. I got turned around and back home safely but then the EGT wouldn't get below 600. After another 10 min I decided it would probably be best to shut down. Then I waited a few min. and did the key on-off-on-off-on routine and got no codes for either the PCU or ECU. I do have an EZ hooked up and disconnected it but did not notice any change. Sorry for being so long winded anyone have any ideas? The bad part is I'm supposed to leave on a 4 day trip in the morning.

 

[MCummings]

Sounds like a stuck pac-brake.



Most likely Electrical,, check your connecctions, dry 'em up, then use some electrical grease to put 'em back together.



Hopefully somebody else can chime in here and help with what conections to check.



Merrick Cummings Jr

 

[Ron Bissett]

One thing to check ,The brass filter on the switch next to the little vacuum hose it controls the air in and if plugged cause the brake to stick or could be the spool take apart and clean care must be taken with the O rings and light lube . Bet you did not cover the control switch when you used the hose on the motor . Ron in Louisville . P. S work the valve linkage by hand to clean out the water that could have gotten in to the vac line or cylinder .

 

[johnmoore]

Unfortunately I did not cover the solenoid. I have downloaded the instructions on cleaning it from the Pacbrake web page. I also downloaded a page on maintenance tips for the Pacbrake. Guess what I will be doing in the morning before my trip to Lou-a-vul? Listen Ron, if you're in the area Sunday I'm headed up to the BBC around 5.

 

[Evan A. Beck]

The solenoid is probably ok... The problem is usually the spool valve. Once it gets a little wet, it likes to stick--usually in the brake-applied position. I have taken apart many seized valves, and found the best fix is to buff the spool valve with some Scotch-Brite or real fine sandpaper. The clean everything up real good, lubricate it with some teflon-based grease, and put it back together. Should work fine now, even if it gets a little damp.

 

[johnmoore]

Just finished cleaning up the Pacbrake. I took it off and cleaned it the best I could then sprayed some silicone on all moving parts. I also did the solenoid just in case. Started the truck up and turned the brake on and off and it woked. So it looks like all is well again. Thanks to all for your help.