Air Brakes

[RufusEarl]

My second post on this problem, hopefully I can explain my problem better this time. The coach is a 95 Country Couch Intrigue, with a 300 Cummings. 18 months ago I replaced the air compressor air dryer, with a kit. I also replaced the governor..

I cannot get the air pressure to rise as it should, it will get to about 90 Pounds and stop. I can idle the engine up using the cruise control, but it still want get past 100 to 110 pounds, not enough for the dryer to purge.

Even at 110 pounds of pressure I cannot get the accelerator to go down, it will go into gear and move but will not accelerate. Also, on the dash I have three red lights. One is the parking brake above that are two red lights one above the other reading Front and Rear. I know this has to do with the air brakes, but cannot understand why the bus will go into gear, with these light on.

I’m sure I’m leaving out information that would be helpful for someone to give their opinion, If you have question please ask and I’ll try to answer the best I can, thanks in advance for all or any help………*

[BFlinn181]

Sounds like your change of the dryer and governor didn't go as planned. Have you checked for any leaks around either component? I'm sure you had higher pressures before the servicing. Not sure why the accelerator isn't operative, 90-110 psi should be enough to operate that. Since you've mentioned air pressures, it sounds like you have gauges, not sure what the red lights indicate.

I know my system, (air over hydraulic) but I don't know yours. I'd take it to a truck shop and have them check it out, perhaps they can explain the 3 lights and why the accelerator isn't working. Air brakes aren't something to not understand or ignore, I'd want it repaired and checked out.

[slickest1]

It sounds like you have a major air leak and the compressor can't keep up with it. the red lights would indicate that there is not enough air built up to make them go off.

I don't quite understand the accelerator problem as it should not relate to the air system. The parking brake would be engaged if there is not enough air in the system. The coach won't want to move when you push on the accelerator if the brakes are on.

[going_postal]

Just for a baseline, why did you kit the air dryer and replace the gov.

[JFXG]

You've now had a chronic compressed air problem for 18 months that is affecting brakes, suspension, and apparently throttle control.
Just out of curiosity, exactly what kind of disaster are you waiting for before you take it to professionals and have them fix it? Enquiring minds.......


John & Diane, fulltiming since '12 02 DS40, FL, Cat, '04 Element NHSO RVM103

[guardrail53]

I strongly suggest you call a "Mobile truck mech." and have him come fix the things you clearly did not have any business messing with! Sorry, but some thing's need to be done by people that understand how the systems work! The new governor is pre-set from the factory, to kick your compressor on at 90 lbs. or so, and kick it off at 120 lbs. or so! From what is sounds to me like you did not fix the air dryer right, and it is leaking air so much, that your compressor is not keeping up! You could bypass the air dryer with a fitting hooking the two lines together, and see if your system works like it should! If it does, then, take the dryer off, and take it to a shop that knows how to rebuild it, or if your MH is building air, and the lights are all off, brakes releasing as they should, then you could drive it to the shop, and have the air dryer rebuilt! As you have found out, sometimes it is best to leave important things like your braking system to the Pro's!
Also, you did not say why you attempted to do this yourself? 18 month's ago? Really??
Rail!

[twinboat]

The compressor pumps air down a line, past a one way check valve and into a tank, when the engine is running.
Because of the check valve, once you shut off the engine, the air will stay in the tank and the line will have no pressure in it.

If the line from the compressor to the tank, including the air dryer, is leaking, it will only leak while the engine is running.

The noise of the engine, makes it very difficult to hear a leak.

You need to closely examine that line for chaffing, behind the hold down clamps and anywhere it may have rubbed, and all of the connections.

When you do build up 110 PSI will it hold that pressure with the engine off ?

If you push the park brake button in, with more than 70 PSI, does it stay in ?

Was this low air problem the reason you rebuilt the air dryer and replaced the governor ?

You say your throttle doesn't work but the cruise control increses the engine RPM. You may have a separate electrical problem there.

If you are not understanding this, you will want to hire someone with air brake experince to get things right. Let him explain what he is doing, to gain some knowledge.

[mpierce]

Originally Posted by JFXG

You've now had a chronic compressed air problem for 18 months that is affecting brakes, suspension, and apparently throttle control.
Just out of curiosity, exactly what kind of disaster are you waiting for before you take it to professionals and have them fix it? Enquiring minds.......


John & Diane, fulltiming since '12 02 DS40, FL, Cat, '04 Element NHSO RVM103

Go to a Professional. Please.

[TR4]

RufusEarl,
You posted this same question in the Country Coach section. Members posted questions for you to help diagnose your problem. You didn't reply back and now your starting a new thread. We can't help you if you don't reply back to our questions.

[deandec]

Originally Posted by slickest1

I don't quite understand the accelerator problem as it should not relate to the air system. .

He likely has an "air throttle valve" behind the accelerator pedal as I do in the same vintage Country Coach.

It needs air pressure to respond although 90 psi should work for the throttle.

[TQ60]

Air leaks can be simple to fix but it takes some skill to do so.

The kit could have been done wrong or something is broken.

We changed our dryer with factory rebuilt as first the cost was about 1/2 and the kit was not complete ( sent it back to gillig).

The simple and safe process here is to locate the hose connection at the compressor and connect it to a stand alone air compressor so the system can be pressurized without engine running.

Soapy water and young ears to hear the hissing and the location of the leak should be essy.

Repair maybe not.

The systems are very simple collection of many pipes and hoses connected to simple but critical valves and other devices that combined can be a complicated system.

Experts know where to look based on experience and Diy do not have that advantage.

If this is not understood get a certified tech yo fix it.

[BFlinn181]

RufusEarl, looking at threads you've posted to, you mention changing out the dryer kit not 18 months ago, but 3 years, 7 months in the past!! (43 months)

Post #9

Has the RV not been driven for over 3 and a half years??

[twinboat]

Originally Posted by deandec

He likely has an "air throttle valve" behind the accelerator pedal as I do in the same vintage Country Coach.

It needs air pressure to respond although 90 psi should work for the throttle.

I agree it may have an air throttle, but would the cruise control be mechanical ?

I would think the the cruise control would still uses the air actuated control on the engine. He says it works to increse the engine speed.

Maybe not, does your have a separate cable and actuator for the cruise ?

[BFlinn181]

The cruise control could be a cable pull on the same lever pulled by the air throttle. I've seen that set up on diesels before.