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Zondo956 · 03-05-2020, **(Subject: Suspension dump )**

I’ve had suspension stay down on tractor when I start truck a couple times before. I just flip the suspension dump switch and airs up normally.
Today I started noticing a loud air leak when driving. Only happens when compressor fills air tanks to maximum(@130). Stops leaking when I press brake pedal.
Turns out it’s the solenoid that leaks.
Could it be that it’s just faulty or should I be worried it’s an electrical problem?
Also plan on changing out the leveling valve due to it leaking in cold weather. Could that cause the solenoid to act up?
Has anyone experienced similar situation

Brock · 03-05-2020, **(Subject: Suspension dump )**

Swap it to verify, the others should be the same part number.

KWt680 · 04-14-2020, **(Subject: Suspension dump )**

Was there any conclusion to this, I have a 2014 T680 and replaced all the solenoids, leveling valve and the line that goes to the leveling valve still has air coming out no matter if the suspension dump switch is on or off. The suspension dump is the only one that has a twin set of solenoides. So does one solenoid go to the on off switch and the other controlled by the computer?

Zondo956 · 04-14-2020, **(Subject: Suspension dump )**

I installed a new dump solenoid which is the twin set of solenoids you mentioned and that solved my issue.
Do the dump solenoids leak air while the air comes out the leveling valve? Mine did. If solenoids aren’t leaking air I’d say you can rule them out.
You mentioned that you swapped all solenoids. Could it be that you put plugs on wrong solenoids? Bad switch?

KWt680 · 04-15-2020, **(Subject: Suspension dump )**

I replaced all solenoids, fith wheeel, differiential lock and the double solenoid for the suspension dump. It all started when I left the truck overnight with the dump switch in the dump position. As far as wires are concerned they are labled and the way the wires are you would have to go out of your way to mix them up. Everything the other solenoids operate work as they should. My question's 1. Why are there 2 solenoids for the suspension. 2. Is one solenoid controlled by the switch on the dash and the other solenoid controlled by the computer to dump suspension??

Paccardude · 08-29-2021, **(Subject: Suspension dump )**

Hi,

This may be a dumb question, but here it goes. I was about to pull out of the yard today, when a gentleman asked how to free the fifth wheel he got stuck behind the king pin on the trailer. I told him all he needs to do is dump the suspension and crank the legs down to get the trailer to sit higher. I saw him 5 minutes later and was still having a time with the issue. I looked inside the 2020 kenworth and there is NO DUMP SUSPENSION BUTTON. How do you let the air out of the bags on a 2020 KW??
(The issue was resolved, he just had to keep cranking the landing gear, but damn why no suspension dump?)

Rawze · 08-29-2021, **(Subject: Suspension dump )**

(08-29-2021 )Paccardude Wrote: Hi,

This may be a dumb question, but here it goes. I was about to pull out of the yard today, when a gentleman asked how to free the fifth wheel he got stuck behind the king pin on the trailer. I told him all he needs to do is dump the suspension and crank the legs down to get the trailer to sit higher. I saw him 5 minutes later and was still having a time with the issue. I looked inside the 2020 kenworth and there is NO DUMP SUSPENSION BUTTON. How do you let the air out of the bags on a 2020 KW??
(The issue was resolved, he just had to keep cranking the landing gear, but damn why no suspension dump?)

my prostar does not have a suspension dump.. I have never really needed it, even when making this same mistake and trailer fully loaded.

Paccardude · 08-29-2021, **(Subject: Suspension dump )**

hmmmmm, So do you have to open up the air tanks to empty the air bags? I figured it was normal to have suspension dump. I use it all the time when i disengage from the trailer king pin, I ease up a foot and engage the suspension dump when dropping trailers.

Rawze · 08-29-2021, **(Subject: Suspension dump )**

(08-29-2021 )Paccardude Wrote: hmmmmm, So do you have to open up the air tanks to empty the air bags? I figured it was normal to have suspension dump. I use it all the time when i disengage from the trailer king pin, I ease up a foot and engage the suspension dump when dropping trailers.

just jack the trailer up on the legs a bit, tilt the 5th wheel forward, and pull forward, is all I ever do if I jump over the king pin.