How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jeremy Your Own Question
Jeremy
Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 2781
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
9290743
Type Your Medium and Heavy Trucks Question Here...
Jeremy is online now
A new question is answered every 9 seconds

I have a 2000 Volvo VNL 660 and the trailer control valve in

Customer Question

I have a 2000 Volvo VNL 660 and the trailer control valve in the dash board is leaking, ita has never been changed.I bought a new valve which was updated and has the exhaust connection in the valve at 1/4" instead of the 3/8".I've got an adaptor for it but I can't figure out how to install it.
Submitted: 10 months ago.
Category: Medium and Heavy Trucks
Expert:  Wayne replied 10 months ago.

Hi I'm Wayne

I will help you with this

is it a screw in adapter or push in , let me know

Customer: replied 10 months ago.
Push in Part# ***** says in the bulletin that 1/4" tubing and the adaptor\must be used on the exhaust line into the pneumatic harness.
Customer: replied 10 months ago.
it looks like push in on one side and the other is like a screw in.
Expert:  Wayne replied 10 months ago.

Thank you for that

what seems to be the issue, wont go in

is there a plastic ring around the top of the fitting,

if yes you push down on that

Customer: replied 10 months ago.
Push in is for the 1/4" tube and screw in suppose to go to a 3/8" tube I guess
Expert:  Wayne replied 10 months ago.

Hi

So you can not push it in ??

Customer: replied 10 months ago.
I can push in on one side of the adaptor that has a quick connector but not on the other side.
Expert:  Wayne replied 10 months ago.

Hi

The other side is a screw in , you mentioned

Customer: replied 10 months ago.
I looked again the other side is like a plastic tube but I'm not sure if it would fit in a 3/8" air tube.
Expert:  Wayne replied 10 months ago.

Hi

So you have a plastic tube sticking out the valve

and you need to install it to a 3/8 plastic line

that should be the exhaust port with the tube

Customer: replied 10 months ago.
I will explain more.The old Trailer Valve had a 3/8" tube out of exhaust that was connected to the 3/8" connector of the Parking Valve exhaust.The new Trailer valve has 1/4" tube sticking out of exhaust and should be connected to the pneumatic harness which I presume is the exhaust from the Parking Brake Valve in the dash.
Expert:  Wayne replied 10 months ago.

Thank you for that

Ok, I knew it was the exhaust with the plastic tube

what you need is a air line coupler (union)

1/4 to 3/8, to join them

I hope this helped you

Hi if this helped you

Please rate my answer 3 or more stars

If you need more info, use request button

Not Poor/Bad service

Wayne

Customer: replied 10 months ago.
That's what the adaptor supposed to be.I thought that you might have changed an updated trailer valve and knew exactly what I was talking about.Your answer doesn't help me.Sorry.
Expert:  Wayne replied 10 months ago.

Hi

No I have not done the up date

Sorry I could not help you

I will opt out of this and send to another expert

Don't reply or rate me as it locks question back to me

Wayne

Expert:  Jeremy replied 10 months ago.

My name is ***** ***** I will assist you.

Do you have a picture of the whole back of the valve? I think the 1/4" you are referring to just goes to a hose you make and you stick it out of the firewall on the truck to exhaust out the air when you set the brakes so the valve can move. The newer valves exhaust out of the valve into the air and not into the old lines as before. You still have your air inlet in, the line to the tractor, the line to the trailer, but an additional exhaust port for the valve itself. I think that might be the valve that you have.

__________________________________________________________________________________________________________________________
You want a 5 star service and I want to provide a 5 star service. Please consider that I don't know your skill level as well as I can't see,
touch, smell, hear the vehicle/machine in question. Please provide as much detail as possible and I will provide as much back.

Once an answer is provided, you should see a rating screen. Please rate my personal service to you. The ratings are my personal feedback,
they are not the site feedback.

Thank you for allowing me to assist you through Just Answer!

Jeremy

Customer: replied 10 months ago.
Ok it makes sense because there is no way to stick a hose into one end of the adaptor but the problem is what do I do with the black exhaust hose from the parking brake that supposed to go into the trailer valve.
Customer: replied 10 months ago.
I replaced the parking brake valve also because I thought I was loosing air there but actually I am loosing air at the trailer valve.
Expert:  Jeremy replied 10 months ago.

Those valves were updated on the new trucks and instead of the places making the old valve, they are forcing the older trucks that replae them to use the newer ones. They flow a bit different and that is why they added that exhaust valve on it. When I have to replace them on older rucks, they confuse me as well and I'll fight for hours until I remember that it just exhaust ports the valve itself and not the system like the older valve did.

If you get a hold of 1800airbrake and tell them what the valve is, they will tell you exactly what line to put where or send a diagram to you. I use them quite a bit. The service is 100% free to use and they know their air lines on every single truck on the road.

Customer: replied 10 months ago.
I have called Bendix as you suggested and they told me about the truck dash valve which I installed correctly but they didn't tell me about the trailer valve which is a Volvo part.I found a schematic from Volvo on how the tubes go between the truck and trailer valve and it shows that the supply line from the truck valve will have a T connector and a tube from the T will go to the supply at the trailer valve but now I don't know what am I going to to with the old supply line that was going to the trailer valve separately from the truck valve.
Customer: replied 10 months ago.
I have added the picture I found at Volvo for the valves.