P38A EAS dropping at rear

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The plus 1.5" may well be due to weight transfer as the front left dropped a lot.
This morning the Front Left was significantly lower than all the others, so leak has moved from back to front !! Using my manual control box, I re-inflated FL again, and the RR dropped back to where it was last night. So rear leaks improved, but not perfect yet.

Much soapier water, and finally found a slow leak bubble on front left outlet on valve block. Air-bag connectors have no leaks at all. Manged to re-seat the line, and no bubbles so far, but I suspect that vibration while driving wont help.

As all the airlines have nicks & scratches from years in the collets, I'm gonna do them in stages. First step will be replace the last few inches at the valve block & join them using compression fittings rather than push fit. If this works then no need to replace the entire airline, plus I then have easy disconnect joints near the valve block.
 
This morning the Front Left was significantly lower than all the others, so leak has moved from back to front !! Using my manual control box, I re-inflated FL again, and the RR dropped back to where it was last night. So rear leaks improved, but not perfect yet.

Much soapier water, and finally found a slow leak bubble on front left outlet on valve block. Air-bag connectors have no leaks at all. Manged to re-seat the line, and no bubbles so far, but I suspect that vibration while driving wont help.

As all the airlines have nicks & scratches from years in the collets, I'm gonna do them in stages. First step will be replace the last few inches at the valve block & join them using compression fittings rather than push fit. If this works then no need to replace the entire airline, plus I then have easy disconnect joints near the valve block.
Are the compression fittings made for plastic pipe? The plastic push fit work well in my experience with commercial air powered systems.
 
Are the compression fittings made for plastic pipe? The plastic push fit work well in my experience with commercial air powered systems.
Yes plus I’ve ordered the 4mm sleeves to go inside the pipe. Same as compressor fittings.

Push fit are great for commercial systems with continuous air supply but not for holding pressure when car is parked. Not paying silly money for high-end push fit when compression works well.

Pete.
 
I think the car somehow knows I've ordered airline fittings, etc. Last night it has risen 1/2 inch at rear, and front is still at normal height !!

Strange.
 
As said many times, the only things about a solenoid valve that can cause a corner to drop is a leak on the small O'ring under the valve seat or the solenoid end seal. Every other O'ring on a solenoid valve can only leak when the corner being filled with air.
 
As said many times, the only things about a solenoid valve that can cause a corner to drop is a leak on the small O'ring under the valve seat or the solenoid end seal. Every other O'ring on a solenoid valve can only leak when the corner being filled with air.

Agreed, which is why I bench tested the valve block fully. Doesn't explain the rear rising overnight though.
 
Inlet valve possibly leaking pressurising gallery and overcoming weak or damaged rear solenoid valves.
That's what I was looking for on the bench test. With 100psi at tank connection, and 60psi on corner outlet, the gauge didn't move at all. But then on the car the tank is 30psi higher, and the 1/2 inch rise was overnight.

For now I'm focussing on sorting the airlines where they enter the block, and not worried about 1/2" over 12 hours !!
 
That's what I was looking for on the bench test. With 100psi at tank connection, and 60psi on corner outlet, the gauge didn't move at all. But then on the car the tank is 30psi higher, and the 1/2 inch rise was overnight.

For now I'm focussing on sorting the airlines where they enter the block, and not worried about 1/2" over 12 hours !!

Yep not worth bothering about.
 
While I'm waiting for the compression fittings, today I re-checked the output on both my pumps. They seem to achieve >150 psi with gauge directly on the pump, but on the car I can only get the tank to 125psi because the pressure switch stops the pump. :eek: Same thing happens on my spare valve block on the bench. Tried two pressure gauges but result is same within a few psi.

So it seems I have two duff pressure switches, that both close at 120-125 psi. Surely it should be >140 psi according to RAVE ? Do these things change with age.
 
While I'm waiting for the compression fittings, today I re-checked the output on both my pumps. They seem to achieve >150 psi with gauge directly on the pump, but on the car I can only get the tank to 125psi because the pressure switch stops the pump. :eek: Same thing happens on my spare valve block on the bench. Tried two pressure gauges but result is same within a few psi.

So it seems I have two duff pressure switches, that both close at 120-125 psi. Surely it should be >140 psi according to RAVE ? Do these things change with age.

I seem to recall anywhere between 120 and 140 is OK? Mine's 140psi but I am sure my original was 130psi.
 
The problem is it opens again just under 120 so pump kicks in again. There’s supposed to be the 120-140 difference so small adjustments in height that only use a little air don’t cause the pump to continuously stop & start.
 
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