Air Purge Every 30 Seconds

[96 Wideglide]

Dennis, ,where did you get the diagram you included? I'd like to see the diagram in section 6 they refer to. I have the Meritor system saver 1200 dryer.

[barmcd]

Originally Posted by 96 Wideglide

Dennis, ,where did you get the diagram you included? I'd like to see the diagram in section 6 they refer to. I have the Meritor system saver 1200 dryer.

Its here.

http://www.meritorwabco.com/MeritorW...ument/mm34.pdf

[96 Wideglide]

Thanks!

[barmcd]

Originally Posted by 96 Wideglide

Thanks!

You're welcome.

[barmcd]

On another note. I wanted to make sure the air dryer was working so I opened the drains for all three tanks to see if I had any water in them and they were dry. A puff of Desiccant shot out of each one. I shut the valves fairly quickly, should I expel it from the tanks?

[CountryB]

What are seeing that you are describing as a "puff of desiccant". The desiccant is a granular substance and is supposed to be contained in the drier cartridge.

It can't get into the tanks unless something is wrong (like the desiccant cartridge broke internally). Maybe that is what happened with the "old" cartridge. In that case you should open the tank drains and get all that desiccant out.

If you continue to see desiccant granules at the tank drains you should go back and inspect the Dryer Cartridge for damage.

[barmcd]

Originally Posted by CountryB

What are seeing that you are describing as a "puff of desiccant". The desiccant is a granular substance and is supposed to be contained in the drier cartridge.

It can't get into the tanks unless something is wrong (like the desiccant cartridge broke internally). Maybe that is what happened with the "old" cartridge. In that case you should open the tank drains and get all that desiccant out.

If you continue to see desiccant granules at the tank drains you should go back and inspect the Dryer Cartridge for damage.

It's a puff of dust. No granules.

I dropped the pressure to about 30 lbs and opened the drain cock and immediately a puff of dust shot out. It stops almost immediately, but you can close the valve and open it again and you get another puff.

[barmcd]

Originally Posted by 96 Wideglide

Dennis, ,where did you get the diagram you included? I'd like to see the diagram in section 6 they refer to. I have the Meritor system saver 1200 dryer.

Ben, the Wabco SS1200 installation manual says you need a pressure controlled check valve somewhere in the system between the dryer and one of the tanks. The SS1200 regenerates the desiccant in the dryer by taking air from the system. The valve make sure the SS1200 can't suck all the air back out of the system if it malfunctions.

The placement is determined by the total volume of the tanks and can be before the wet tank or one of the two dry tanks. Do you know where your pressure controlled check valve is located in your system?

Thanks

[CountryB]

Originally Posted by barmcd

It's a puff of dust. No granules.

I dropped the pressure to about 30 lbs and opened the drain cock and immediately a puff of dust shot out. It stops almost immediately, but you can close the valve and open it again and you get another puff.

See if you can catch some (maybe hold a cloth under the drain as opening). You may just be seeing a vapor mist and not desiccant.
Does not sound like you have a problem.

[96 Wideglide]

Originally Posted by barmcd

The placement is determined by the total volume of the tanks and can be before the wet tank or one of the two dry tanks. Do you know where your pressure controlled check valve is located in your system?

Thanks

I haven't located it yet, but when the weather improves I'll start searching around the tanks.
Since I'm getting random air releases from the purge valve, hours after compressor shut down, high possibility it could be this valve.

[Jon_C]

Barmcd idont know if you resolved this but if not i have a thread where i removed the extra stuff on outside of my dryer and it solved the problem.

http://www.irv2.com/forums/f115/air-...ght=15+seconds

[barmcd]

I had to use the lower unit rebuild kit--a rubber piece disintegrated inside the dryer.

[Jon_C]

While installing the lower kit i found the same rubber inside my purge valve and thought for sure that was the problem but also had to remove the extras to get it to stop.

[96 Wideglide]

Originally Posted by barmcd

Ben, the Wabco SS1200 installation manual says you need a pressure controlled check valve, somewhere in the system between the dryer and one of the tanks. The SS1200 regenerates the desiccant in the dryer by taking air from the system. The valve make sure the SS1200 can't suck all the air back out of the system if it malfunctions.

The placement is determined by the total volume of the tanks and can be before the wet tank or one of the two dry tanks. Do you know where your pressure controlled check valve is located in your system?

Thanks

Well, finally solved this issue!
Narrowed it down to either the pressure controlled check valve, mentioned above by Dennis,(which is on the inlet to the secondary tank), or, an issue with the regeneration valve in the air dryer. Mine was releasing some air thru the purge valve, a second, or third time between compressor load cycles ( even with the engine shut off).
Found a brand new dryer, that came supplied with said pressure protection valve, as a kit. Dryer is easy to get to on my Scepter, so I decided to change that first.
Lucky for me, that fixed the issue . After purge, the dryer releases air for 15-20 seconds ( this is the regeneration valve drying out the desicant filter for the next load cycle), and that's it! No more air release till the air pressure has depleted to load cycle !
I'll dig into the old dryer when I'm retired and have nothing but time. I suspect I'll find an issue with the regeneration valve.