Spring Brakes with ICC Brake Valve?

[gus]

Rick,

As Brian has said, DD3 is just another type of spring parking brake, but more troublesome than regular spring brakes. I have them on my 4107 and, believe me, regular spring brakes are far better and I haven't even had to repair them yet!!

Spring parking brakes are spring brakes because they are operated by powerful springs, not air, and are held open by air pressure.

The old ICC is a completely different type of brake, not a parking brake bu an emergency brake only. It will work as a parking brake as long as you have air pressure, but, no pressure, no brake - not good!!

Almost any type of valve can be used with spring brakes as long as it serves the functions of releasing air from the spring brake canister. I've seen the old toggle type that was used long ago to release front brakes only when that was the current thinking.

[Rick59-4104]

 Thanks Gus,
That was the reason for my confusion, I thought the DD3's were a single canister (non spring) brake original to the 4104 and 4103 bus, I knew I had spring brakes on the 04, just did not realize that DD3's are also spring brakes, so we were talking in the previous posts about 3 different brake systems and I thought we were discussing 2 systems.

My mistake and sorry to all for all the confusion in my previous post's.

Rick

[rampeyboy]

If I wasn't confused before, I sure am now! At this point as much as I hate to do it, I will be taking the Scenic to someone more qualified than me for brake repairs! Normally I aint scared of much, but I just aint willing to play with brakes that I dont know enough about!
Boyce

[Rick59-4104]

 Boyce,
Probably the most practical sensible post on this entire thread.


  Take it to someone who will let you watch and if you have to pay them extra to explain everything brake related do so.


Rick

[RJ]

Rick -

To add to the confusion:

The simple way to tell what type of brake chambers you have on the rear drive axle is to determine how many air lines are attached:

One air line = old, original single canister.  No parking brake circuit of any type.  OEM  on your 4104.  ICC valve was for emergency braking only, once air in system bleeds off, brakes WILL release.

Two air lines = Current-style spring brakes.  Used for both parking brake and emergency brake.  Will automatically set if vehicle air pressure drops below about 60 psi.  Most common parking/emergency brake cans used today, along with the yellow push/pull valve.  Simply pushing valve down when coach low air warning buzzer shuts off will frequently release the brakes.

Three air lines = DD3 brake chambers.  Used for both parking brake and emergency brake.  Like spring brakes, will automatically set if vehicle air pressure drops below about 60 psi.  Due to design, requires a full service brake application for 3 - 5 seconds with coach air built up to 100+ psi before they will release.  No longer in production, rebuild kits available. 


IMHO, if your coach, in fact, does have spring brakes, I'd suggest you figure out how to remove the ICC valve and properly plumb in one of the common yellow valves.  Think of this modification as a safety issue - if somebody unfamiliar had to move your coach (such as a tow rig) - they'd easily recognize the yellow parking brake button, whereas the old ICC valve would probably make them go "huh?"

FWIW & HTH. . .

[buswarrior]

A warning to busnuts:

It would be best to be very cautious in choosing someone to work on the brakes of your coach if re-design or re-engineering of the system is required.

Sad to say, that mechanic may be more stunned about the situation than you are.

But he will take your money and pretend really convincingly.

There is nothing in a traditional mechanic's training that equips one to build a brake system.

Maintain a stock one? yes.

Design or re-design? a very loud NO!

be careful.

happy coaching!
buswarrior

[thomasinnv]

Someone please correct me if I am wrong, but I do believe that DD3 ARE NOT spring brakes. The two types of systems operate on completely different principles.

[buswarrior]

Correct. DD3 chambers are not spring brake chambers.

I think the various posts are playing fast and loose with a variety of terms.

Both DD3 and spring brake chambers have combined service and parking features.

The parking feature is also employed in some fashion as an emergency brake in both systems.

Spring brake chambers for parking use have widely taken over as the only solution for activating drum brakes on today's heavy vehicles. DD3 stopped being manufactured by Bendix at the end of 2008.

DD3 came into use before spring brakes, use air from an isolated tank to activate the parking portion, as well as there being locking rollers to prevent release when the air pressure leaks away, and air from another tank for the service portion. This redundancy was unheard of at the time of their invention, everyone was parking with handbrakes and air applied parking circuits in single circuit air systems. Wheel chocks ruled the day in the heavy vehicles.

happy coaching!
buswarrior

[Rick59-4104]

 Thanks to everyone who posted, I for one feel better educated about not only the brake system on the 4104 but the other types of brakes as well. If this information keeps anyone out of trouble it was worth it.....I will be checking into replacing the ICC value with the one I should have.

Rick

[Len Silva]

Print out the Air brake Handbook and study it thoroughly.  Just about everything you need to know is there.  Every bus nut should have this available.

http://www.wsafc.org/WSFMA/Shared%20Documents1/Bendix%20Air%20Brake%20Handbook.pdf

[artvonne]

  So looking at my MC5, single line fronts, triple line rears, I have DD3 on rears, and old single cannisters on the fronts? I have noticed I have to apply the brakes pretty good to unlock them.

  RJ says to update the old spring brakes, BW says to maintain stock. I'm guessing I could install a yellow air valve in place of the stock black knob so it would appear current to anyone, leave the rest of the system alone and just bring it all up to kosher??
 

[challenger440]

Paul, on my mc7 the fronts and the tags are single line brake chambers.  Only the drive axle brakes are the three air line system.  That's the parking brake.  John M.

[RJ]

RJ says to update the old spring brakes, BW says to maintain stock. I'm guessing I could install a yellow air valve in place of the stock black knob so it would appear current to anyone, leave the rest of the system alone and just bring it all up to kosher??

Paul -

You've misunderstood my comment to Rick.  I was suggesting he replace the old ICC valve with the current yellow push/pull, since his coach now has spring brakes.

For your coach, it ain't broke - don't fix it!

FWIW & HTH. . .

[artvonne]

For your coach, it ain't broke - don't fix it!

  Is there any physical or mechanical difference between the old style black knob brake valve I have, and the newer style yellow knob brake valve? I thought both were simple dump valves to blow the air. 

[gus]

Paul,

To repeat other posts, if it works don't mess with it. I spent untold frustrating hours trying to eliminate the ICC valve and gave up. It works and works well.

4103s and 4104s came with only the mechanical drum parking brake. The result is that it is very tight fit to install spring brake chambers, but it is well worth the trouble. I don't think I could ever trust those drum parking brakes.

I may have given you the impression that DD3s are spring brakes but they aren't. I sometimes get confused on that myself because they work pretty much the same from the driver's seat. Mine will hold without being set by foot first but I usually do it anyway. However, as already posted, they usually must be released by foot after pushing in the knob. However, again, mine release automatically about 90% of the time if I haven't pushed the pedal in real hard to set.

That really clears it up!!!

Springs are better.