Jump to content

Air Dryer replaced, no air pressure since


Recommended Posts

2001 40' Monaco Diplomat 330 Cummins Roadmaster Chassis

Had a mechanic replace a 10 year old air Dryer.

Driving home every time I braked air pressure would go lower but never would build higher.

Any ideas?

2001 40' Monaco Diplomat 330 Cummins

Mitchell of Florida

Link to comment
Share on other sites

1 minute ago, mitchellg2241 said:

2001 40' Monaco Diplomat 330 Cummins Roadmaster Chassis

Had a mechanic replace a 10 year old air Dryer.

Driving home every time I braked air pressure would go lower but never would build higher.

Any ideas?

2001 40' Monaco Diplomat 330 Cummins

Mitchell of Florida

Did the mechanic replace the whole dryer unit ?

Or just the dryer filter ??

 

Big difference 

Link to comment
Share on other sites

How short of a ride home was this?

Wouldn't take too many stops before your tank pressure would get low enough to put on your emergency / parking brake, if no air was getting from your compressor to your tanks.

Link to comment
Share on other sites

Hmmm.

So you left the shop with full air tanks. He would have likely drained all three tanks before changing the filter. That air got into the tanks after he put the new filter on somehow.

This one is a headscratcher. 

 

Link to comment
Share on other sites

25 minutes ago, mitchellg2241 said:

Just the filter.

I had all filters changed, fuel, oil and air dryer.

Very  few traffic lights or stops to home, but just made it.

Your relief valve may be bad.

You can buy a re build kit.

Not very expensive. 

The mechanics should have caught this issue with a test drive.

 

Link to comment
Share on other sites

17 minutes ago, mitchellg2241 said:

I will be speaking to them and I believe they will come out. He mentioned we maybe got a faulty air dryer.

Anything I can check?

Would I hear air leaking or any other simple checks?

Have them come out

They sent you off with possibly 🤔

A faulty air system. 

Not good at all.

 

Link to comment
Share on other sites

Legit just went through this if it's the old Haldex 33100 I received a faulty dryer as  Well…

 

To start take the control line or unloader line off your air dryer to see if there is coming out of it that will give you almost a clear indication as to why you are not building or pressure.

 

Simple push fitting use a open ended wrench to push in and pull the small airline out.. Just guessing but with the motor running you probly will have air coming out of that control line.. I'm just finishing up replacing my entire air dryer governor and compressor head. .

 The defective unit I received add a badd Turbo valve internally.

Link to comment
Share on other sites

32 minutes ago, 96 EVO said:

Hmmm.

So you left the shop with full air tanks. He would have likely drained all three tanks before changing the filter. That air got into the tanks after he put the new filter on somehow.

This one is a headscratcher. 

 

I was in the RV as it was changed. If they fully drained the tanks I would of heard the low pressure alarms when I started the engine.

Do the tanks ALWAYS get drained when changing the air dryer filter

Link to comment
Share on other sites

Posted (edited)
10 minutes ago, mitchellg2241 said:

 

Do the tanks ALWAYS get drained when changing the air dryer filter

I guess not.

He's relying on the tank check valves. 

I drain my tanks before removing the old filter. The Meritor Wabco dryer uses supply and secondary dry tank pressure to regenerate the desicant filter. Remove one while you still have air in your tanks, you risk the thing blasting out of your hands when you get to the last thread!

*edit* Now I think of it, the air would start releasing as soon as the seal left the housing. Long before you got to the last thread.

Edited by 96 EVO
  • Like 1
Link to comment
Share on other sites

When I was changing my air dryer out I took the drain plug off to see if it was dirty and just for kicks..  Mind you the air dryer was off the truck and all the tanks were drained before removing and that plug shot out of the drain like a rocket.  So that drain area must hold at least some air pressure even after draining the tanks.

Link to comment
Share on other sites

This thread reminded me that I had not changed the filter on mine. So I changed it today. I am wandering if he missed the internal o'ring on the filter. Drain your tanks and remove the filter and make sure o'ring is in place and the big seal is there and neither are crimped.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...