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Wayne
Wayne, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 8426
Experience:  worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling
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QR-1C valve is leaking, what could be doing this?

Customer Question

QR-1C valve is leaking, what could be doing this?
Submitted: 11 months ago.
Category: Medium and Heavy Trucks
Expert:  Wayne replied 11 months ago.

Hi I'm Wayne

I will help you with this

this is normal to leak over time, the rubber diaphragm

wears out , just need to replace it

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 11 months ago.
I replaced the QR valve, tractor/trailer dash valve, foot treadle valve, brake chambers, brake service relays and they're all fine. It happens when the brakes are released and applied. I eliminated the primary air that supplies the rear brakes, and the leak still happens. So basically I'm only using the secondary air that supplies the front brakes and such to test only.
Expert:  Wayne replied 11 months ago.

Hi

Thank you for that

Did you replace the front QR valve ??

You covered most of the basics, valve replacements

click here

this shows what makes it leak

I hope this helped you

Customer: replied 11 months ago.
I replaced the front QR valve and nothing changes. I eliminated the front brakes by taking off the hose that goes from the brake valve to the front qr valve or front service brake valve. So I hit the brake pedal with no brakes obviously but there is still a small leak coming out of the rear QR valve. It may have to do something with the supply tank/secondary tank or air dryer, maybe the compressor. Would a bad check valve or safety valve on the air tanks or air dryer cause this?
Expert:  Wayne replied 11 months ago.

Hi

Thank you for that

No to Compressor, No to Drier

But yes air tank check Valve

I hope this helped you

Customer: replied 11 months ago.
Which air tank would the valve be on? The wet supply tank or secondary tank? Would it be the one going to the brake valve from the secondary tank or the supply tank going to the secondary tank?
Expert:  Wayne replied 11 months ago.

Thank you for that

it would be secondary tank

Primary would bleed back to compressor

Customer: replied 11 months ago.
the check valve would be at the secondary tanks for the line going to the brake valve? Is there another check valve on the secondary tank for the line that supplies it from the supply tank (wet tank)?
Expert:  Wayne replied 11 months ago.

Hi

The 1st check valve comes from the compressor/Drier

the 2nd check valve comes into play at the 2nd tank,

this is a silly question, but I have to ask ....

are your brakes adjusted correct, reason being

that will cause it

Customer: replied 11 months ago.
they're adjusted. With these check valves on the air tanks, they're only supposed to allow air out and not back through the tank its coming from right? Do all the hoses from and to the tank have check valves? As of now I'm only using 2 air tanks to test the leak. The supply wet tank and the secondary tank. I only see 2 red hoses on the secondary tank, the one supplying to the brake valve and the other one coming from the supply tank which supplies the air to the secondary tank.
Expert:  Wayne replied 11 months ago.

Hi

Sorry for the delay, Grand Kids Over

yes they only let air one way , not back

I will have to say this is a starnge one

does this happen only to tractor , or with the trailer hooked up

Customer: replied 11 months ago.
only to tractor. when brakes are released and i apply the brakes, air somehow backfeeds to the parking brake line back to the QR valve exhaust port. Do all of the hoses that comes from and to the secondary tank have check valves? Because one hose supplies air to the secondary from the supply wet tank and the other hose goes from the secondary to the brake valve. Might the secondary tank be bad? Does the secondary tank have an internal valve inside of it or just outside?
Expert:  Wayne replied 11 months ago.

Hi

Thank you for that

If this is the tractor only,

did this happen after you started changing valves,

r this is the reason you changed valves

Problem was always only the tractor ......Correct

Customer: replied 11 months ago.
tractor only, it happened all of a sudden before i changed valves.
Expert:  Wayne replied 11 months ago.

HI

Thank you for that

We need to move back,

I know you replaced the multi function valve

either it is faulty , or lines have mixed up ,

This is a cause

Customer: replied 11 months ago.
The service relay valve for the rear brakes?
Expert:  Wayne replied 11 months ago.

Hi

The brake valve for service, park brake

Customer: replied 11 months ago.
there's no multi function valve, theres only a service brake valve and quick release valve in the rear separately and a qr valve and 2 service valves in the front.
Expert:  Wayne replied 11 months ago.

Thank you for that

do your lines from the service brakes , and park brakes all go to same valve ??

or are there 2 different valves , 1 for park, and 1 for service brakes

Customer: replied 11 months ago.
2 different valves.
Expert:  Wayne replied 11 months ago.

Thank you for that ,

which valve did you replace

Customer: replied 11 months ago.
All of them. Does the supply wet tank and secondary air tank has a one way check valve on them,? so air doesn't reverse back where it came from?
Expert:  Wayne replied 11 months ago.

Hi

yes it has a check valve from compressor to wet tank

then another from wet tank to dry tank

Customer: replied 11 months ago.
it has a check valve from compressor to wet tank- the valve from the compressor to the wet tank, there's a hose coming from the compressor to the air dryer then out to the wet tank....-where exactly is the valve, on the compressor or wet tank?then another from wet tank to dry tank....- the valve from the wet tank to dry tank, is it on the wet tank or on the dry tank? And which dry tank, the primary or secondary air tanks?
Expert:  Wayne replied 11 months ago.

Hi

It is on the front of the wet tank

the line that goes to drier to tank

it is on the tank

Customer: replied 11 months ago.
I tried to find a check valve on the wet tank and I couldn't find one, neither on the secondary tank. I can't find a one way check valve.
Expert:  Wayne replied 11 months ago.

Thank you for that

I never did ask you what are we working on ??

Customer: replied 11 months ago.
a leak on the exhaust port of rear QR valve. I tried checking and replacing almost everything you can think of.
Expert:  Wayne replied 11 months ago.

HI

No I meant, Year ,make model

Customer: replied 11 months ago.
2004, volvo vnl 670. isx cummins
Customer: replied 11 months ago.
Do you have like a air system diagram of the volvo?
Expert:  Wayne replied 11 months ago.

Morning

I have 3 other experts helping me on this one,

we are at a loss ,with everything already being replaced

does it do it w/o a trailer

also do you have the trailer hand brake

Customer: replied 11 months ago.
it does it without a trailer and with a trailer. i dont have a trailer hand brake
Expert:  Wayne replied 11 months ago.

Thank you

OK as I mentioned , I have 3 other experts working on this also with me

we are to a dead end, except look for a double check valve the fppt brake,

or in that line

Customer: replied 11 months ago.
Any hope?
Expert:  Wayne replied 11 months ago.

Hi

I am so sorry , we are at dead end, nobody can get volvo diagrams

they just don't share

Just had to share this from another expert

call 1 800 Air Brak

We are all at a loss

Customer: replied 11 months ago.
it'd be pointless asking another expert? I just want to know I tried it with just the secondary air system and it leaks, then i tried it with just the primary air system and it leaks, and obviously it leaks when both are operating. And it even leaks with the secondary system, except I disable the secondary brakes, which is the front and it still leaks. I've never had this happened before. I was thinking it was something with the supply wet tank and I don't see anything. I don't even see a one way check valve on the supply or secondary tanks. I can't find any other valve
Expert:  Wayne replied 11 months ago.

Hi

Yes as mentioned 3 other experts helping on this issue

I have said , and mentioned . might have received the wrong QR valve, or it is defective,

you replaced almost everything in the system

we spent 3 days and lot of hours on this,

I am trying to help, I really am, but I am not getting any pay for all the time spent

I am not being sarcastic, by any means , but we hit a dead end here

and there is a 1 way check valve on every air tank

I explained where it was 2x . they have to have it

can you send me a Pic of air tanks

Customer: replied 11 months ago.
I'll send the pics tomorrow when I get back to the truck. I only saw one check valve on the primary tank, which connects to a hose coming from the supply wet tank, I guess that's to prevent air going back to the supply tank. On the secondary tank, there's a hose coming from supply tank, theres no check valve on that hose going to the supply tank, it just looks like a fitting. And on the supply tank, there is no check valve on there, I just see fittings. I see only a safety valve on the supply tank.
Expert:  Wayne replied 11 months ago.

Hi Thank you for that

Did you replace that check valve as I mentioned 2-3 times ???

Yes Pic would be good

Wayne

Customer: replied 11 months ago.
The double check valve on the foot brake?
Expert:  Wayne replied 11 months ago.

Hi

Yes the air tank, and Yes the foot valve

did you or not replace them ,

Customer: replied 11 months ago.
replaced the foot valve.
Expert:  Wayne replied 11 months ago.

HI

Yes I know That

what about the check Valve ????

what about the air tank check valve ???????

Customer: replied 11 months ago.
I changed the only one I see on the primary tank which goes to the supply tank and it still leaks. I already told you.
Expert:  Wayne replied 11 months ago.

Thank you for that

I need pic of your system

something is not adding up to this

as I mentioned , Volvo DOES NOT GIVE OUT INFO ON THERE TRUCKS

DIAGRAMS, NOT ANY THING

you need a title to get a key made

Customer: replied 11 months ago.
Ok relax, I had already told you I'm going to get the pics of the tanks tomorrow. We're starting the new year, no need to get like that.
Expert:  Wayne replied 11 months ago.

Morning

Sorry , did not mean to come off that way

it is just that Volvo, will never help you

they want it in there shop

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