Air leak ??

[Dtwallace]

Originally Posted by joeplazek

I had dryer purge valve problems and the recommendations I got was change the dryer. I did and have never regretted it. I wont lie to you that I know much about these units.


Joe

Yep, we are saying the same thing, just the phraseology is different.

So once the OP comes back to us with the verdict, we'll know for sure, and I'm betting on the air dryer.

DTW

[1doodadd]

Originally Posted by guardrail53

Those only leak when the brakes are applied, foot on the pedal!
Stuck open air drier, be my guess?

Rail!

When you set the parking brakes via Yellow valve on dash, All brake cans apply, even the T20 cans. Yes even with out the Foot Pedal, you have enough air pressure in the air tanks, and that air will be used to activate All brake cans. That is why we have Maxi cans, or spring brakes on the Drivers, don't need air to be applied. T20's on the tag. If you have ever goon through a CHP truck scale inspection you are told to kill the engine and release the brakes, and Yes he will chock the tires. That is so the inspector can inspect all your brakes and see if you have any out of adjustment. And Yes if one is out, you will be sited, and it must be adjusted before it can go back in service.

So back to why I made My statement. Until the air is exhausted from sitting or a small air leak. That brake can is being used as an active brake.

[Dtwallace]

Originally Posted by 1doodadd

When you set the parking brakes via Yellow valve on dash, All brake cans apply, even the T20 cans. Yes even with out the Foot Pedal, you have enough air pressure in the air tanks, and that air will be used to activate All brake cans. That is why we have Maxi cans, or spring brakes on the Drivers, don't need air to be applied. T20's on the tag. If you have ever goon through a CHP truck scale inspection you are told to kill the engine and release the brakes, and Yes he will chock the tires. That is so the inspector can inspect all your brakes and see if you have any out of adjustment. And Yes if one is out, you will be sited, and it must be adjusted before it can go back in service.

So back to why I made My statement. Until the air is exhausted from sitting or a small air leak. That brake can is being used as an active brake.

Sir,
I have to respectfully disagree with that statement.

For the parking brake, there's a disc or drum brake arrangement which is designed to be held in the 'applied' position by spring pressure.

Air pressure must be produced to release these "spring brake" parking brakes.

Spring brakes were designed so there would always be a fail-safe method of stopping an air brake vehicle, if for some reason, all air supply pressure were suddenly lost while the vehicle is in motion.


For the service brakes (the ones used while driving for slowing or stopping) to be applied, the brake pedal is pushed, routing the air under pressure (approx 100–120*psi or 690–830*kPa or 6.89-8.27 bar) to the brake chamber, causing the brake to be engaged.

What we sometimes call the pancake brake chamber is completely out of the picture when the parking brake is applied.

Now, I'd like to bring up a little history of the air brake system. There was once a trailer system in the old days designated the 747 air brake system.

This was prior to the spring brake or compound air chamber as it's called. The 747 parking brake system required air to keep trailers in place because it was only pancake brake chambers on these trailers.

There were a lot of incidents of trailers rolling away when air pressure was lost if not chocked during the times these systems were in use.

Today, it is against safety regulations to incorporate that type system on any automotive air brake equipped vehicle. This is now a world standard.

[guardrail53]

Originally Posted by Dtwallace

Sir,
I have to respectfully disagree with that statement.

For the parking brake, there's a disc or drum brake arrangement which is designed to be held in the 'applied' position by spring pressure.

Air pressure must be produced to release these "spring brake" parking brakes.

Spring brakes were designed so there would always be a fail-safe method of stopping an air brake vehicle, if for some reason, all air supply pressure were suddenly lost while the vehicle is in motion.


For the service brakes (the ones used while driving for slowing or stopping) to be applied, the brake pedal is pushed, routing the air under pressure (approx 100–120*psi or 690–830*kPa or 6.89-8.27 bar) to the brake chamber, causing the brake to be engaged.

What we sometimes call the pancake brake chamber is completely out of the picture when the parking brake is applied.

Now, I'd like to bring up a little history of the air brake system. There was once a trailer system in the old days designated the 747 air brake system.

This was prior to the spring brake or compound air chamber as it's called. The 747 parking brake system required air to keep trailers in place because it was only pancake brake chambers on these trailers.

There were a lot of incidents of trailers rolling away when air pressure was lost if not chocked during the times these systems were in use.

Today, it is against safety regulations to incorporate that type system on any automotive air brake equipped vehicle. This is now a world standard.

Thanks DT, you answered this very well, and did so before I got to it! Rail!

[joeplazek]

Originally Posted by Dtwallace

Yep, we are saying the same thing, just the phraseology is different.



So once the OP comes back to us with the verdict, we'll know for sure, and I'm betting on the air dryer.



DTW

I have a friend that owns a huge truck fleet. His mind set is Dryers are consumables. Just change them after a certain length of time. Probably does not pertain to motorhomes but mine is a 1996 and road salts and such do great things.


Joe

[palehorse89]

The air dryer filter/cartridge should be changed every 3-5 years depending on your location and humidity where you use it..........it is the first line of defense to having dry tanks and air lines................
Are you saying yours has never been changed/serviced? since 1996?

[joeplazek]

Originally Posted by palehorse89

The air dryer filter/cartridge should be changed every 3-5 years depending on your location and humidity where you use it..........it is the first line of defense to having dry tanks and air lines................
Are you saying yours has never been changed/serviced? since 1996?

My dad has owned this coach since new. I don't think he ever serviced it and I know I had not.

[Dtwallace]

Originally Posted by joeplazek

I have a friend that owns a huge truck fleet. His mind set is Dryers are consumables. Just change them after a certain length of time. Probably does not pertain to motorhomes but mine is a 1996 and road salts and such do great things.


Joe

Yea, the fleet maintenance way of thinking is a little different than how we care for our investments.

In a fleet of trucks, replacing the air dryer assembly on just one of 20 trucks (if) it needs it, out weighs spending $50 bucks a year on 20 trucks each to service the air dryer, Its all about bottom line.

For us, it's a sense of pride, safety, and value that we have for our equipment. it's not a money maker, it's part of our lives. Same with all of our personal vehicles, don't you agree??

DTW

[Dtwallace]

Originally Posted by joeplazek

My dad has owned this coach since new. I don't think he ever serviced it and I know I had not.

Joe,

If you want to enjoy that coach as long as your Dad did, maybe a little (TLC) is in the future.

DTW

[joeplazek]

Originally Posted by Dtwallace

Yea, the fleet maintenance way of thinking is a little different than how we care for our investments.



In a fleet of trucks, replacing the air dryer assembly on just one of 20 trucks (if) it needs it, out weighs spending $50 bucks a year on 20 trucks each to service the air dryer, Its all about bottom line.



For us, it's a sense of pride, safety, and value that we have for our equipment. it's not a money maker, it's part of our lives. Same with all of our personal vehicles, don't you agree??



DTW

I do agree. I tell everyone the coach is my hot rod or race car now. I work on it all the time and keep it in top shape. I kills my pride when I have a problem on the road.


Joe