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supertech52
supertech52, Heavy Duty Truck Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 73
Experience:  ASE Certified Technician 32 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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1996 western star ,fitted with black brake spring push pull

Customer Question

1996 western star ,fitted with black brake spring push pull valve ,red trailer supply valve , when you release park brakes , air starts releasing from back of park brake valve at dash , have replaced park brake {black} valve at dash ,have replaced double check valve at chassis rail closest to r14 valve drivers side chassis rail ,and replaced r14 valve on passengers side chassis rail .air still leaks from behind black park brake valve , only when brakes are released
Submitted: 8 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 8 months ago.

Hi David, My name is***** will try to help. Check for a leaking brake chamber or a faulty brake valve above the rear axles bypassing internally. Let me know

Customer: replied 8 months ago.
have checked all brake chambers for any possible leaks .or any form of back flow of air ,none found ,after replaciong double check valve drivers side chassis rail , i noticd fine leak at r14 valve in passengers side chassis rail, replaced it , only air leak in braking system comes from park brake release valve , only when you release park brake
Expert:  Daniel Wilson replied 8 months ago.

Thanks for the update. The dash valve that is leaking is also new?

Customer: replied 8 months ago.
all replaced parts are brand new
Expert:  Daniel Wilson replied 8 months ago.

Does it leak when you press the foot brake with the park brake released?

Expert:  Daniel Wilson replied 8 months ago.

Sounds like you might have gotten a faulty valve right out of the box

Customer: replied 8 months ago.
have you any more advice as to what the cause of air leak could be
Expert:  Daniel Wilson replied 8 months ago.

I would need to access the air schematic for your VIN. I am out of ideas but possibly another expert might have a diagram for your air system. What is the last 8 of your VIN?

Expert:  Daniel Wilson replied 8 months ago.

I am going to opt out to open this up for other experts to see if they can offer any schematics or further suggestions.

Expert:  Jeremy replied 8 months ago.

My name is ***** ***** I will assist you with your question today.

I'm an independent contractor and I don't get paid until a rating has been made. No rate, site gets it all.

We can go back and forth as needed to help resolve the issue you are having. Follow ups are free after ratings, so rate in confidence!

Did it leak like this before you changed the valve? Did you check the treadle (foot) valve?

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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 8 months ago.
asked for the VIN No. 2WLPDCXH8TK943902 , The advice he has given has been of no help , the parts out of box being faulty is not justified ,due to air leak has not varied from previous installed vehicle parts ,to new brand new parts installed . he has opt out of further advice , so im to assume that you will be attending to this air leak advising Jeremy , the treadle foot valve is operating correctly .the air back feed is coming from the back of spring park brake push pull valve ,
Expert:  Jeremy replied 8 months ago.

Which line is it leaking out of? You are getting a back feed to the valve and it needs to be determined if it is from the primary or secondary system. If you can, cap on line at a time as well as the fitting until you can push the button in and the air stops. I would start with the trailer valve first. This will rule out the trailer circuit backfeeding from the hand valve as well as the trailer valve itself. Let me know the result. It will just be a process of elimination at this point.

Customer: replied 8 months ago.
The air starts leaking once you release the black spring brake push pull valve which makes the air leak associated to the primary air supply.
Expert:  Jeremy replied 8 months ago.

CLICK HERE go to this manual and refer to section 42.

You are getting a back feed from another valve. It can be the spring valve in the back or a relay valve. You will have to go line by line on the vales to see which is back feeding. If the yellow and red valves are not feeding back, then it has to be coming from another location in the system. It will require hands on where the internet won't be much help in this one.

Customer: replied 8 months ago.
are you a able to get the air brake system schematics and email them through for 1996 western star , the VIN No.has been supplied to you if that is of a help to yourself to get the information , as you need to be aware this brake system on vehicle is a, BLACK spring brake push pull valve , only consisting with a RED trailer supply push pull valve .
Expert:  Jeremy replied 8 months ago.

I did that already and see it didn't attach right. I will try again.

CLICK HERE Go to section 42. That has your diagram.

Expert:  Jeremy replied 7 months ago.

I see you viewed this and this is still showing as a open question due to no positive (3 stars or more) rating.

Did you still need assistance with this?

Customer: replied 7 months ago.
Good day Jeremy , the file you tried to send has failed , so im unable to download it from mediafire,air leak is still same, hopefully with air brake schematics to VIN CHASSIS No is able to be forwarded from yourself , a better diagnosis maybe obtained , thank you
Expert:  Jeremy replied 7 months ago.

That is because 10 days have gone by and the file deletes after 7. Why didn;t you download it the last 2 times I posted it up? I am charged $5 per pull. I have to pass the cost on to you. I will try and get a Premium Service offer added for this.

In order to send again, I will be charged so I have to pass that on since I have not gotten a rating yet from the previous times I sent it.

Expert:  Jeremy replied 7 months ago.

It's not letting me so I have asked for assistance in this matter with the tech team...

Expert:  supertech52 replied 7 months ago.

When does the air leak exactly, when you push in or when you pull out. Many people get this confused, I really need to know when push it in or when you pull the valve out, when does it leak, thanks.

Customer: replied 7 months ago.
Goodday , supertech52 sorry about lateness of reply but have other committments that take me away and unable to relpy promptly sometimes , im not aware if you are able to sight previous conversations regarding air leak at black spring brake push pull valve , air leak only starts after you release spring brake push pull valve , black spring brake valve has been replaced , double check valve has been replaced and R14 valve been replaced ,no air leaks from any 30/30 springbrake chambers nor any back feeding
Expert:  supertech52 replied 7 months ago.

No problem, I too have been busy. I am able to read through the previous conversations.

  1. That tells me- that ( leaking) is when you push the button in?
  2. Just to clarify one more time, the valve that leaks, is the valve that releases the brakes?
  3. How many lines are on the valve? You have a supply and a delivery, and then an exhaust port.
  4. And does the air leak out the exhaust port?

Sincerely,

supertech52

John Vieira

Customer: replied 7 months ago.
good day John , the air leak only starts after you pull black valve to release the brakes , and will cease any leaking when brakes are applied . the are leak is at black push pull valve , which has been replaced with new valve , as thinking was originally the push pull (black) was faulty , but no problem is else where , if your unable to assist ,ive requested a refund from justanswer to seek resolution from another source . but if you knowledge to my resolution is available ,it to would be appreciated ,