Medium and Heavy Trucks

Have Truck Repair Questions? Ask an Expert

Ask an Expert,
Get an Answer ASAP!

Medium and Heavy Trucks
This answer was rated:

Air dryer started purging every minute and a half or so. No…

Air dryer started purging...

Air dryer started purging every minute and a half or so. No loss in pressure. Swapped the air dryer and new governor. Started doing that I’m very cold weather. Still doing the same thing after new parts. Next morning pressure gauges were reading MAX air pressure. Stopped and drained the tanks. Added anti freeze to the lines and built pressure back up again. Now it’s pirgkng every 3 minutes or so. Pressure saying around 130.

Mechanic's Assistant: What is the complete model and serial number of your machine?

Hmm not sure. Truck is freight liner cascadia with Detroit series 60

Mechanic's Assistant: Anything else you want the equipment mechanic to know before I connect you?

The old and new air dryer make “rattle snake” noise before it purges. This new one does it for about 10 seconds or so

Show More
Show Less
Ask Your Own Medium and Heavy Trucks Question
Answered in 31 minutes by:
1/19/2018
Don
Don, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 1,700
Experience: journeyman mechanic over 40 years experience
Verified

hi there my name is don i will try to help you on this

did you have a look at the old dryer to see if there was a lot of oil build up on the purge valve

did you get a lot of moisture out of the tank ?

purging at 130 is normal how about the exhaust ports on the quick release valve and the ABS valve ? what year is your freightliner ? did you put air brake antifreeze from the compressor

is your model dryer a adip model

during the question period you will not be charged anything until i press the answer on my end and you see the rate me pop up at your end

don

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
Didn’t get a chance to look at the old air dryer. It’s a 2009 cascadia. It was -4 or so when this started happening. Hard to say if a lot of moisture came out due to weather. From what I read on few sites it could be the unloaded valve. Or anything else that I could look at before that?

hi there thanks for that information

if your talking about the compressor unloader valve it is working normal from what your saying

the purge valve on the dryer could be sticking but its new correct and you plugged in the heater right ?

but you changed the whole dryer right or just the canister ?

don

Ask Your Own Medium and Heavy Trucks Question

do your brakes hang up a bit or release normally ?

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
Yeah it’s a brand new air dryer and new governor. Seems like the compressor is just always working. Pressure stays put at 130. And about every 3 minutes i hear the rattle snake noise from the dryer and then the “sneeze”. Breaks seem to release normally.

hi there thanks for that great information

have you tried a leak down test yet to see if you have an air leak

is the truck empty of air when you pick it up or shut it off for awhile ?

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
Usually empty overnight.

hmm thanks for that information

have you tried a leak down test ?

build pressure up to 100 lbs release the brakes make a brake application shut the truck off and maintain brake application for three minutes and see if the pressure drops more that 10 lbs

can you do that and let me know

how long does it take the compressor to build air between 50 and 90 lbs should be under 2 minutes

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
Not able to do it right now. Is it possible to continue in the morning ? I’ll do the leak down text first thing

hi there sure thing

however i live in western canada so i am on mountain time

right now its 10:16 pm

i do have an appointment at 1:00 pm tomorrow afternoon till about 3 pm

so in the morning untill 12:00 noon or after 3 pm mountain time what ever works good for you

by the way i am a red seal Canadian government licenced mechanic and air systems are one on my specialties

Don

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
Sounds good thank you!

Have a great night

Don

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
Good morning. Ok so while holding the breaks down it lost about 25lbs in the 3 minutes and took about 2:15 mins to build it up from 50-90psi

hi there thanks for that great information

compressor build time is a little long ( thats at 1200 rpm correct ?)

the pressure drop of 25 lbs means that there is a leak somewhere in the system could be the reason that the compressor is working to keep up pressure

did you check the the hose off the discharge of the compressor and the fitting in that is goes to for carbon build up sometimes the carbon build up on the compressor head holds the valve open

take the fitting of the compressor when the hose goes from the compressor to the air dryer and have a look at the fitting see if there is a lot of carbon build up and also look at the hose to see if it has lots of carbon

my feeling is this that you still have moisture in the system and it might be freezing up one of the Valves

or on the tank its self you have a 90 lb protection valve on the tank and small plastic lines coming off it

if you do not have a air system alcohol (air brake antifreeze ) injector i would put one in the cost is $ 90.00 and an easy install you fill it with air brake antifreeze and it injects it into the air system just after the air-dryer . so the line that comes off the air dryer going to the primary tank goes to the injector then the line comes out the other side of the injector to the air system

this keeps the system clean and keeps ice from forming . i put them on all our trucks because they see such a drastic change in temperature hauling freight

as for your air leak make sure the air is up to max make sure you block the wheels

shut the truck off and see if you can hear an air leak if not it may be in the brake application system

release the brakes ,either have some one push on the brake peddle and hold it or pull the spike down

make a spray bottle with soap and water mix of if it cold fill with windshield washer fluid

spray all the air line connections on the valves and air tanks also spray around the clamps of the brake pots if there is a leak it will indeed bubble up if nothing from the cab back then open the hood and do the same there the leak will show

make sure you maintain over 100 lbs or air pressure in the system this may require starting the truck a couple of times if it is a good leak

it will take about 1/2 hour to check all the lines ,

to install the injector is about the same amount of time

that is what the injector looks like

https://www.haldex.com/en/na/air-dryerair-line/alcohol-evaporator-/

https://www.haldex.com/en/na/air-dryerair-line/alcohol-evaporator-/a72420/

this will give you an idea of the price

https://www.ebay.com/i/302606397389?rt=nc

installation instructions

http://tycrop.com/wp-content/uploads/2015/07/alcohol_evaporator.pdf

if you have a problem installing let me know

have a great day

Don

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
I’m in warmer climate now. I’ll check the discharge valves tomorrow and replace them. I did read a post earlier that recommended to replace the unloaded valve. I did that this morning it def purges less often. But not the issue. Thanks

sounds good

Ask Your Own Medium and Heavy Trucks Question

Rate my service by using the stars at the top of the page.

Just Answer can only compensate me for my time and resources after feedback rating thus rating is required Many thanks

Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 1 month ago
I have another question. So only leak I found was at the fittings to the air tanks. My pressure gauges show 140 psi. Never had it this high. Still purging every 3 mins or so while driving. Could those leaking fittings be the culprit of this unusual behavior
Customer reply replied 1 month ago
Also building up pressure at 1200 rpms from 50-90 took only 1-minuet

Hi there thanks for that great information

the normal pressure is between 135 and 145 so your good there at 140 the only way you can adjust the pressure is at the governor you unscrew the little black cap and you will see a stud and nut in there you would have to adjust it there .

build time is perfect nothing wrong with the compressor

the leaks depending how bad they are it will definitely effect the cycle of the compressor

did you repair them ?

Don and as far as the pressure and purging all is good there not to worry about that

also remember that if the trailer your pulling has leaks and so on that also will effect the compressor cut in and out

Don
Don, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 1,700
Experience: journeyman mechanic over 40 years experience
Verified
Don and 87 other Medium and Heavy Trucks Specialists are ready to help you
Ask your own question now
Was this answer helpful?
Ask Don Your Own Question
Don
Don
Don, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 1,700
1,700 Satisfied Customers
Experience: journeyman mechanic over 40 years experience

Don is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Daniel Wilson

Daniel Wilson

2,322 satisfied customers

Owner at DJ Wilson

Cat Man

Cat Man

Cat Engine Expert

4,247 satisfied customers

I am ASE Master Truck Certified.

Wayne

Wayne

Journeyman

2,640 satisfied customers

worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling

Jeremy

Jeremy

Certified Truck/Bus Technician

2,019 satisfied customers

ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician

cumminsdr

cumminsdr

Mechanic

1,225 satisfied customers

All types of Cummins applications

Curtis B.

Curtis B.

Technician

813 satisfied customers

Technician turned service manager on multiple lines of trucks and engines, used in industry.

dieseldan55

dieseldan55

Contractor

74 satisfied customers

Road Service mechanic for Volvo Construction.

< Previous | Next >

Related Medium and Heavy Trucks Questions
I have a 06 mitsu fusowill crank with good batteries but
i have a 06 mitsu fusowill crank with good batteries but dont start … read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
Head BoltTorque specs and sequence on Komatsu Engine Model
Head BoltTorque specs and sequence on Komatsu Engine Model S4D120 … read more
Curtis B.
Curtis B.
Technician
Associate Degree
813 satisfied customers
The truck is a Mercedes-Benz Actros 2640 (2006 model) vin
The truck is a Mercedes-Benz Actros 2640 (2006 model) vin number WDB(###) ###-#### 435863. The truck will start and run but the instrument panel does not work. The hazard lights will operate but the f… read more
Jeremy
Jeremy
Certified Truck/Bus Technician
Vocational, Technical or Trade School
2,019 satisfied customers
Have a 05 freightliner Columbia info center say no abs and
have a 05 freightliner Columbia info center say no abs and light on and cant detect with computer and switch for blink code just makes light brighter doesn't flash… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
Cat Man, I have a c-13 acert I need to change the valve stem
Cat Man, I have a c-13 acert I need to change the valve stem seals out, can you give me the caterpillar part number for the valve spring compressor for ESN LGK16143. I tried 9U-7241 from a C15 acert b… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,287 satisfied customers
I'm working on a 1995 international 4700 with a manual
I'm working on a 1995 international 4700 with a manual injection pump. Can't get it to fire, motor is a DT466. I changed the pump with the motor set at tdc . The new pump was timed. But not starting, … read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
Paccar px9 active dtc. Kenworth t300 2014 px9. Scan the
I check if a got a blow up fuse nothing but can't found the corect fuse … read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
Have a 2009 Freightliner Columbia 120 two yellow engine
Have a 2009 Freightliner Columbia 120 two yellow engine lights came on one of them is the check engine light the other a solid yellow engine light. Had a fault code that says, ecu 128 sid 146 fail 07.… read more
FIX-IT
FIX-IT
Comercial transport technician
Vocational, Technical or Trade Scho
784 satisfied customers
We have a 97 international 4700 t444e cranks /no start. Was
We have a 97 international 4700 t444e cranks /no start. Was starting fine until brake lights got worked on. Not sure if it's a coincidence or may have something to do with some safety features … read more
Alex Olsen
Alex Olsen
auto/diesel/industrial
396 satisfied customers
I am having a low oil pressure problem with MBE 4000 that
I am having a low oil pressure problem with MBE 4000 that was just overhauled. I replaced the gauge in dash. … read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
I have a mack e-7 engine crank no start no fuel going
i have a mack e-7 engine crank no start no fuel going through injection pump is there a fuel shutoff on this… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
We are trying to align the front suspension of a 2009
Hi we are trying to align the front suspension of a 2009 VanHool … read more
Eurotruck72
Eurotruck72
Garage owner
84 satisfied customers
C-7 cat low oil pressure, has 20 lbs on cold crank, 10 psi
c-7 cat low oil pressure, has 20 lbs on cold crank, 10 psi warm, new oil pump main rod barings, new injectors, new injection control pressure sensor, new bypass in filter housing, all with no change t… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
4,247 satisfied customers
2009 386 with Cummins ISX. Lose throttle and engine light
2009 386 with Cummins ISX. Lose throttle and engine light comes on. Code is throttle position. replaced 2 tps's, both the harnesses to ECM, and the ECM. Added more grounding and cleaned all connection… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
I have a 2005 freightliner m2 that a customer brought in and
hello, I have a 2005 freightliner m2 that a customer brought in and he said they hooked batteries up incorrctly and now both bulkhead module fuses continue to blow? can I confirm the module is bad?… read more
roy
roy
Associate Degree
3 satisfied customers
I have a 3406e in a 1999 kenworth w900. Did an inframe ran
I have a 3406e in a 1999 kenworth w900. Did an inframe ran fine, now today the truck will run fine have great power then it will lose power and there's a knock sounds like in the top end. It doesn't d… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
I have a 2005 international 8600 with a ism Cummins turn to
Good day I have a 2005 international 8600 with a ism Cummins turn to 410. The problem is low power it had an injector bad so replace all 6 new new turbo actuator new turbo control box new turbo speed … read more
Alex Olsen
Alex Olsen
auto/diesel/industrial
396 satisfied customers
I have a 386 peterbuilt an the cab controller primary spn
I have a 386 peterbuilt an the cab controller primary spn 3698 an 3697 code is on … read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x