Air ride ODD ISSUE

[702852]

ot my hands on a 98 Town Car with only 73000 miles.... Really nice condition, but of late I've noticed that the right rear (RR) side is sagging....

Well I went to a parking lot and measured from the top of the bumper to the ground and compared the left and right side. Sure enough there was a difference.

So I got my hands on a diagram of the suspension system and found the "brain" for the suspension....Jumped some wires and was able to lower the LR and RR side individually. Then I jumped the compressor and was able to inflate both the LR and RR separately as well.

So I let the car go back to normal ride height.

Today I hooked up my DMM (digital multi meter) to the valve wire at the suspension module to "see" if the module was putting out 12 volts by itself for the airbag on the RR to raise up.

I got into the car with the DMM on my seat
Turned on the IGN
While standing outside I saw and heard the LR going up and there was voltage on the DMM 13.5 volts so I knew the RR side was getting voltage....

So WHY the heck is the RR side not inflating on its own??? When it inflates fine by me jumping the circuit???? GRRR


Yes I could wire up switches and do it manually, but that's not the point.

 

[slowmkviii]

Try changing the solenoids side to side.

 

[no0c]

ot my hands on a 98 Town Car with only 73000 miles.... Really nice condition, but of late I've noticed that the right rear (RR) side is sagging....

Hi 702852,

Mileage is really not an issue, but time is and if they are the OE springs, they are living on borrowed time. I would bet the expiration date on their birth certificates is approaching fast. You can't expect much more than 15 years.

Ever give any thought to perhaps your RR spring is leaking?

Well I went to a parking lot and measured from the top of the bumper to the ground and compared the left and right side. Sure enough there was a difference.

I would be checking from the wheel opening to ground through the axle centerline.

So I got my hands on a diagram of the suspension system and found the "brain" for the suspension....Jumped some wires and was able to lower the LR and RR side individually. Then I jumped the compressor and was able to inflate both the LR and RR separately as well.

Good troubleshooting techniques !

So I let the car go back to normal ride height.

Today I hooked up my DMM (digital multi meter) to the valve wire at the suspension module to "see" if the module was putting out 12 volts by itself for the airbag on the RR to raise up.

I hope you mean the air spring rather than air bag

I got into the car with the DMM on my seat
Turned on the IGN
While standing outside I saw and heard the LR going up and there was voltage on the DMM 13.5 volts so I knew the RR side was getting voltage....

All you know is that there is 13.5 VDC at pin 25 of the RAS module. Until you check the voltage (with a test light) at the RR spring solenoid (T/W wire), you don't know that it's getting full voltage, nor do you know the integrity of the grounding of that solenoid.

So WHY the heck is the RR side not inflating on its own??? When it inflates fine by me jumping the circuit???? GRRR

1. Bad or intermittent wiring to and away (ground) from the solenoid
2. Leaky air spring via cracks that are exposed when the spring is inflated and seal when it deflates a bit.
3. Flaky, intermittent solenoid operation

I'm betting on #2, because you said when you let it settle back to ride height the sag was there. Turn the RAS switch off. Jack up the right side at the frame so the axle is in 'hang mode' and check the integrity of the air spring bladder when it is unfolded with some soapy water. I would bet the farm the bladder is cracked and leaking and the left spring is not far behind. If that's so, get them replaced A.S.A.P. to avoid undue running and wear on the compressor and the repair gets more expensive when the compressor has assumed room temperature.

Yes I could wire up switches and do it manually, but that's not the point.

Yeah, that's not quite how things are supposed to work.

GL.

Regards,