We sprung a fuel leak in Albany, Oregon last week and while looking for the source of the leak one of the tow truck drivers pointed out that there were bubbles coming from around the seal of the "thing" pictured below. He thought it was a fuel regulator and the source of the fuel leak.

The guy at the garage called it an "air regulator" and said that there was no way this "thing" could be the source of the fuel leak. As it turns out, the cause of the fuel leak was a faulty fuel filter. (We had a new one installed 180 miles earlier and the mechanic forgot to put the water sensor back on the bottom of the filter. Without the sensor the "o" ring on the bottom could not take the pressure and blew out.) I asked him to check this "thing" for leaks anyway and to replace the gasket as I knew it was leaking around the gasket because of the bubbles coming from around the seal.

He could not find either a gasket or a replacement for this "thing". It appears to be made of aluminum.

Does anyone know what this "thing" is?



Thank you.

Carl Feren

I have the same rig you have.
9209-3832-30BS-11B
I WISH I COULD HELP ,I'VE ONLY HAD THIS RIG 10 MONTHS.

Easy to make a gasket but be careful when you take it apart. It could spring at you or is sprung together.You can buy gasket paper in almost any auto store
lenny

What we are looking at, is the bottom of the air dryer. The item circled is "Tee'd" off of the main air feed line.

This item is a low psi cutoff that is found on air circuits to keep you from loosing all air psi at once in the event of a line blowout.

These valves are called "Pressure Protection Valves" I am still at WDC. When I get back I will attempt to find the part number for you.

What you are looking at is Haldex-Midland Pressure Protection Valve. Because you're not using the other 2 ports (B&C) the probable part number is a KN31001 or a KN31011. These are both considered "the norm" when it comes to PSI readings.

You can buy this at NAPA.
Their part# MBI KN31001 or MBI KN31011

Look at this chart to help you figure out which one it is. Look at your valve and see what the last 2 letters are stamped in the part number says. DB or DG

I have stopped a few leaks on diaphragm thingies by disassembling and applying a little Titeseal to the mating surfaces. This also allows you to inspect the diaphragm to evaluate the need for replacement or not.

quote:

Originally posted by wrongturn2:
I have the same rig you have.
9209-3832-30BS-11B
I WISH I COULD HELP ,I'VE ONLY HAD THIS RIG 10 MONTHS.

Thanks for checking out my post; Enjoy your new toy.

Carl Feren

quote:

Originally posted by lenny and judy:
Easy to make a gasket but be careful when you take it apart. It could spring at you or is sprung together.You can buy gasket paper in almost any auto store
lenny

Thanks for jumping in ...

I actually have some gasket material with me but am waiting to change it until I have a spare unit on-hand. More than once I have had to replace a part after dismantling it to replace a gasket. If we weren’t traveling I wouldn’t hesitate to change the gasket. Have you dismantled this part and had it “spring” at you?

Carl Feren

quote:

Originally posted by Bill N.Y.:
What you are looking at is Haldex-Midland Pressure Protection Valve.

.

This is REALLY helpful, Bill. along with all the other advice I got I feel confident about fixing this.

I spoke with SPARTAN this morning about which valve to use based on our VIN#. The correct part is N15759 DD (OEM part #). The OPENING / CLOSING air pressure ratings for our system is 102/88 which falls right in the range for this VALVE. Spartan's price is $42 but he suggested that I get a MERITOR at a local truck shop. He also did not recommend splitting the unit and replacing just the gasket. Apparently this is a factory sealed unit.

Thanks for pointing me in the right direction.

Carl

Carl