Sticking Air Valve

[kwood]

Hi all,

It has been awhile since I worked on my bus due to work.  I went to start and air it up today but it seems like I have a check valve sticking.  My bus airs up on the first tank but builds to 150 psi and pops off.  It does not raise the suspension or fill the brake system.  I don't have easy access to my manuals right now.  I was wondering if someone can direct me where to find the check valve after the first air tank.  It is a 1979 MCI 9.  Also, can I clean this checkvalve out or do I need to replace it?

Thanks for any advice.

Kevin

[robertglines1]

your profile doesn't say where your from. Could be ice problem:frozen moisture in line.   Bob

[bevans6]

It sounds to me like the lines to the governor are frozen, the pop off at 150 psi is where the safety valve is set.  I'd go with frozen lines.

Brian

[kwood]

It could be frozen air lines.  I am in Midland, TX.  It has been in the mid-20's at night warming up to mid-50's during the day.  Maybe it is not warming up enough during the day?  Any thoughts on the best way to handle this?

Thanks!
Kevin

[belfert]

Boy, you would think 50 degrees during the day would melt any ice.  Does your bus have an air dryer?  Has it been serviced recently?

Of course, it did take three or four days in Florida to thaw my 4 gallons of frozen washer fluid.  It was full when I bought the bus, but I didn't realize it was filled with plain water.  (I drained most of the water and put in three gallons of -40 washer fluid.)

[kwood]

It does have an air dryer that was serviced about this time last year.

[Dreamscape]

Wait until it warms up then give it another try. You should have been able to check it out yesterday, as it was around 60° here in Abilene. Most air problems seem to happen when it gets cold, real cold.

Paul

[kwood]

It gets about 60 degrees during the day but mid 20's at night.  I will give it a try again this weekend when it is supposed to be near 70.  What would I do if I really neded to move the bus?

[white-eagle]

i rented a kerosene heater from the local hardware store.  point it at the appropriate places for a few minutes, making sure not to heat anything up too much.  Took mine about a half hour, but the temp was also above freezing by then. Cost me about $15, but i needed to move quickly as we were leaving ohio heading to florida (a few years back).

[robertglines1]

Kwood If you have shop air try filling it thru fill valve in driver-side  front lower compartment.  if is just  stuck not letting the accessory side  fill this might release /free the valve.  also leave door open to warm up inside this compartment as warm air might release pressure valve.

[kwood]

I will try the shop air this weekend.  It might be a problem as a cold front is coming into the area.  I will let you know how it works.  Thanks!

[mlh1936]

My MCI 102A-3 air system froze up a couple of years ago. I aimed my kerosene torpedo heater under there for a few minutes and it did the trick.
Mal

[kwood]

Hmmm.  Mid 60's here today.  I aired up the bus from the left front corner and fired up the bus.  Still cannot get the valve to unstick after the first tank.  Can anyone recommend here the sticking valve might be?  Maybe a couple taps from a hammer will unstick it.

Kevin

[belfert]

If you do find a sticking valve I would rebuild it or replace it with a rebuilt valve.  The air system is critically important to stopping your bus.  You don't want to end up stuck somewhere because of a bad valve.

[Ed Hackenbruch]

Do you drain your air tanks each time you run the bus?  It might not be a valve but the line leaving the tank could be plugged up with crud.