Inoperative Quad Airbag system

[kenneth doyle]

My 1975 GMC has a quadbag system installed by Jim Bounds many years ago. It
has never given me any problems except for some leakage, generally taking a
couple of days or longer to leak down.

I had some engine and other miscellaneous work performed this past week.
Improvements included wiring the radio to the ignition switch, which had
previously been wired to the house battery. The horn relay was also
replaced and a new horn was installed. Also some carburetor work. But no
work was performed on the airbag system. It was working normally.

I drove it home with the bags inflated, but the next morning the bags were
deflated on both sides. When activated, the system would not raise the
coach. or inflate the bags. The air compressor operates to fill the air
tank. I tried to inflate the bags, on both sides, at the air value next to
the system shutoff valves (at the wheels). Neither side would inflate. The
end shut-off valve was closed, the two valves leading to the bags were
open. The airbag air gauges on both sides of the coach would register 75lbs
of pressure, and hold that pressure, unless the end shut-off valve was
opened.

What would cause the system to totally fail in this manner? Could one of
more sensors be out, or was electrical power severed to the system that
during the horn and radio rewiring? Suggestions welcome.

Thanks,

Ken Doyle
1975 Glenbrook
SE Kansas

 

[jim kanomata1]

Don't blame the bag system.
There is a great chance the solenoid valves might have a piece of rust from
the air tank .

On Sat, Dec 19, 2020 at 10:14 AM Kenneth Doyle via Gmclist <

> My 1975 GMC has a quadbag system installed by Jim Bounds many years ago. It
> has never given me any problems except for some leakage, generally taking a
> couple of days or longer to leak down.
>
> I had some engine and other miscellaneous work performed this past week.
> Improvements included wiring the radio to the ignition switch, which had
> previously been wired to the house battery. The horn relay was also
> replaced and a new horn was installed. Also some carburetor work. But no
> work was performed on the airbag system. It was working normally.
>
> I drove it home with the bags inflated, but the next morning the bags were
> deflated on both sides. When activated, the system would not raise the
> coach. or inflate the bags. The air compressor operates to fill the air
> tank. I tried to inflate the bags, on both sides, at the air value next to
> the system shutoff valves (at the wheels). Neither side would inflate. The
> end shut-off valve was closed, the two valves leading to the bags were
> open. The airbag air gauges on both sides of the coach would register 75lbs
> of pressure, and hold that pressure, unless the end shut-off valve was
> opened.
>
> What would cause the system to totally fail in this manner? Could one of
> more sensors be out, or was electrical power severed to the system that
> during the horn and radio rewiring? Suggestions welcome.
>
> Thanks,
>
> Ken Doyle
> 1975 Glenbrook
> SE Kansas
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[kenneth doyle]

Jim,

I'm a big fan of the airbags themselves.

I'm assuming there are two solenoid valves, one for each side. It is
certainly possible that the airtank has released rust, etc., through the
system. The tank is old and doesn't hold pressure as well as it used to. In
fact, I'm not sure it's even pumping up more than 80psi at the moment. It
may need to be replaced too. Is there a way to clean the solenoid valves,
or do they need to be replaced?

Thanks,

Ken

On Sat, Dec 19, 2020 at 12:24 PM Jim Kanomata via Gmclist <

> Don't blame the bag system.
> There is a great chance the solenoid valves might have a piece of rust from
> the air tank .
>
> On Sat, Dec 19, 2020 at 10:14 AM Kenneth Doyle via Gmclist <

>
> > My 1975 GMC has a quadbag system installed by Jim Bounds many years ago.
> It
> > has never given me any problems except for some leakage, generally
> taking a
> > couple of days or longer to leak down.
> >
> > I had some engine and other miscellaneous work performed this past week.
> > Improvements included wiring the radio to the ignition switch, which had
> > previously been wired to the house battery. The horn relay was also
> > replaced and a new horn was installed. Also some carburetor work. But no
> > work was performed on the airbag system. It was working normally.
> >
> > I drove it home with the bags inflated, but the next morning the bags
> were
> > deflated on both sides. When activated, the system would not raise the
> > coach. or inflate the bags. The air compressor operates to fill the air
> > tank. I tried to inflate the bags, on both sides, at the air value next
> to
> > the system shutoff valves (at the wheels). Neither side would inflate.
> The
> > end shut-off valve was closed, the two valves leading to the bags were
> > open. The airbag air gauges on both sides of the coach would register
> 75lbs
> > of pressure, and hold that pressure, unless the end shut-off valve was
> > opened.
> >
> > What would cause the system to totally fail in this manner? Could one of
> > more sensors be out, or was electrical power severed to the system that
> > during the horn and radio rewiring? Suggestions welcome.
> >
> > Thanks,
> >
> > Ken Doyle
> > 1975 Glenbrook
> > SE Kansas
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.gmcrvparts.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Matt Colie]

> Jim,
>
> I'm a big fan of the airbags themselves.
>
> I'm assuming there are two solenoid valves, one for each side. It is certainly possible that the airtank has released rust, etc., through the
> system. The tank is old and doesn't hold pressure as well as it used to. In fact, I'm not sure it's even pumping up more than 80psi at the moment.
> It may need to be replaced too. Is there a way to clean the solenoid valves,or do they need to be replaced?
>
> Thanks,
>
> Ken

Ken,

The system is well described in the X7725 manual.

There are not two solenoid valves, but six and any of two per side could cause the that side to leak down. Of those I have had apart, they are
serviceable, but they required a special two pin spanner. I have no reason to suspect the GM used that same supplier for all the Electro-level
systems.

You will probably have to break up the valve cluster to get the access required.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[Matt Colie]

Ken,
Is it also a refit with Sullybags?
The Firestone airspings in the Sully set are know to sometimes block the fill ports when all the way down.

By other remarks, I am guessing that the coach is an ElectroLevel.
If that is the case, then it is highly likely that they disconnected the feed to the switch bank.

Now all you have to do is find out where they dropped it? They probably disconnected it to attach the feed for the stereo.

Speaking of, why do you want the radio off the main engine battery?

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[kenneth doyle]

Matt, I prefer the possibility that feed was dropped to the switch bank
rather than a contaminated solenoid cluster. I will pursue that first. The
panel for the airbag system says Power Level II. I will speak with the
mechanic tomorrow and perhaps I can get him to swing by to look at it.

We only listen to the coach radio when on the road. I've left it on several
times after exiting the coach for extended periods. That was the reason for
moving radio power to the ignition.

Thanks for your input.

Ken

On Sun, Dec 20, 2020, 9:23 AM Matt Colie via Gmclist <

> Ken,
> Is it also a refit with Sullybags?
> The Firestone airspings in the Sully set are know to sometimes block the
> fill ports when all the way down.
>
> By other remarks, I am guessing that the coach is an ElectroLevel.
> If that is the case, then it is highly likely that they disconnected the
> feed to the switch bank.
>
> Now all you have to do is find out where they dropped it? They probably
> disconnected it to attach the feed for the stereo.
>
> Speaking of, why do you want the radio off the main engine battery?
>
> Matt
> --
> Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> GMCES
> Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> Brakes with Applied Control Arms
> SE Michigan - Near DTW - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[jim kanomata1]

We supply a spanner socket to enable you to disassemble .
No need to purchase new solenoid valves.
It is unusual to have both sides leaking the same way.

On Sun, Dec 20, 2020 at 10:38 AM Kenneth Doyle via Gmclist <

> Matt, I prefer the possibility that feed was dropped to the switch bank
> rather than a contaminated solenoid cluster. I will pursue that first. The
> panel for the airbag system says Power Level II. I will speak with the
> mechanic tomorrow and perhaps I can get him to swing by to look at it.
>
> We only listen to the coach radio when on the road. I've left it on several
> times after exiting the coach for extended periods. That was the reason for
> moving radio power to the ignition.
>
> Thanks for your input.
>
> Ken
>
>
>
> On Sun, Dec 20, 2020, 9:23 AM Matt Colie via Gmclist <

>
> > Ken,
> > Is it also a refit with Sullybags?
> > The Firestone airspings in the Sully set are know to sometimes block the
> > fill ports when all the way down.
> >
> > By other remarks, I am guessing that the coach is an ElectroLevel.
> > If that is the case, then it is highly likely that they disconnected the
> > feed to the switch bank.
> >
> > Now all you have to do is find out where they dropped it? They probably
> > disconnected it to attach the feed for the stereo.
> >
> > Speaking of, why do you want the radio off the main engine battery?
> >
> > Matt
> > --
> > Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> > GMCES
> > Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> > Brakes with Applied Control Arms
> > SE Michigan - Near DTW - Twixt A2 and Detroit
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[kenneth doyle]

Why would the bags not inflate with air pressure being applied at the bags
themselves with the valve to the rest of the system closed, but valves to
the bags open?

Thanks, Ken

On Sun, Dec 20, 2020, 10:32 PM Jim Kanomata via Gmclist <

> We supply a spanner socket to enable you to disassemble .
> No need to purchase new solenoid valves.
> It is unusual to have both sides leaking the same way.
>
>
> On Sun, Dec 20, 2020 at 10:38 AM Kenneth Doyle via Gmclist <

>
> > Matt, I prefer the possibility that feed was dropped to the switch bank
> > rather than a contaminated solenoid cluster. I will pursue that first.
> The
> > panel for the airbag system says Power Level II. I will speak with the
> > mechanic tomorrow and perhaps I can get him to swing by to look at it.
> >
> > We only listen to the coach radio when on the road. I've left it on
> several
> > times after exiting the coach for extended periods. That was the reason
> for
> > moving radio power to the ignition.
> >
> > Thanks for your input.
> >
> > Ken
> >
> >
> >
> > On Sun, Dec 20, 2020, 9:23 AM Matt Colie via Gmclist <

> >
> > > Ken,
> > > Is it also a refit with Sullybags?
> > > The Firestone airspings in the Sully set are know to sometimes block
> the
> > > fill ports when all the way down.
> > >
> > > By other remarks, I am guessing that the coach is an ElectroLevel.
> > > If that is the case, then it is highly likely that they disconnected
> the
> > > feed to the switch bank.
> > >
> > > Now all you have to do is find out where they dropped it? They
> probably
> > > disconnected it to attach the feed for the stereo.
> > >
> > > Speaking of, why do you want the radio off the main engine battery?
> > >
> > > Matt
> > > --
> > > Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> > > GMCES
> > > Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> > > Brakes with Applied Control Arms
> > > SE Michigan - Near DTW - Twixt A2 and Detroit
> > >
> > > _______________________________________________
> > > GMCnet mailing list
> > > Unsubscribe or Change List Options:
> > > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> > >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.gmcrvparts.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>