Thread: SLS & Onboard Air Installation Advice

Originally Posted by John_D2

A few questions got the brains trust. I've picked up a 2nd hand ARB onboard air compressor which has the original hose fitting plus 2 electric air solenoids attached. I think a previous owner used it for diff locks.

I'd like to have onboard air as well as SLS. I can pick up an air tank at a good price.

So...

1. Can I plumb the compressor up to the tank. I know this answer is yes.

2. Can I move the solenoids to the tank and use them to supply the left & right Airbags? Yes -

3. Can I use the height controllers (standard ones) to control the solenoids? Yes

4. How do I do all this plus add exhaust vents to the bags? He He - you need RAVE wiring diagram assuming the vehicle already has SLS or ACE,
You just need a supply/exhaust solenoid from the new tank to the existing solenoids.
If no SLS or ACE from factory you will benefit/need the male orange plug from an ACE/SLS vehicle to pick up the input/output wires needed from the SLABS - and your temporary electrician friend.

5. I have a friend who's an electrician, so he can help with the wiring side. He may not be your friend for long.

6. Can I wire this all up without using the BCU to control it all YES but ...the BCU does not control the SLS however does need to know (provides inputs) to the SLS if fitted.
You can set up an SLS system without the factory ECUs but no benefit is gained by attempting to exclude them when a reliable system is already in place.
The system will work best using the existing SLABS capability and IMO will be problematic and unnecessarily complicated to achieve an inferior final result if BCU and /or SLABS is attempted to be excluded.

7. Is it easier to modify the ARB compressor to run on the existing wiring & forget about onboard air?
Its dozens of hrs easier to just run a separate AOB system than attempt to integrate into a functioning SLS

Enjoy

Hi John,

Did your D2 come with SLS then have coil conversion?

A few suggestions if I may?

If you get a standard sls valve block and supply this with the onboard air supply via original wiring.
Also could use one of the arb valves in place of the "original compressor"
Then use the other arb solenoids as the exhaust?? I'm not 100% on the exact function of the exhaust valve originally but assuming it would exhaust either the left or right when required valve opens. ie: lower left - left valve and exhaust open together??

So the arb valve would need to exhaust the main line into the original valve block. Not sure if that's how the arb ones would have worked as diff/locks?

Alternatively you could just get a 12volt inline exhaust valve from an alternate supplier?
Like this one? you'd need to check the exact operation, a local supplier would be my preferred option!
未命名 1

Hope this helps!

PS My SLS reinstall is going great! Defiantly worth doing!!

Cheers Lemo

My bad, yes my D2 came with SLS. The previous owner had trouble with the compressor. So instead of replacing the bags he removed the compressor & put in coils. Everything except the bags & compressor is still in place. The SLS was turned of at the computer.

From what I'm hearing so far I could either use the ARB as an onboard air & have a seperate SLS, or use the ARB as the pump for the bags & organise another way of pumping tyres up

I'm wondering if I should just buy a 2nd hand compressor, rebuild it with bagpipingandy, & use my ARB as an onboard air system. Then the SLS stays factory.

Thoughts?

A compressor is a compressor I think you're over-thinking it. Remove springs, replace bags, mount arb compressor in place of original. Tap in a hose for your inflation line, turn SLS back on and drive away

Originally Posted by donh54

A compressor is a compressor I think you're over-thinking it. Remove springs, replace bags, mount arb compressor in place of original. Tap in a hose for your inflation line, turn SLS back on and drive away

Agreed. How do I convert wabco fittings to ARB?

Originally Posted by John_D2

Agreed. How do I convert wabco fittings to ARB?

Hi John,

If you can find a good second hand compressor I'd go this route. Easiest way I'd think!! And use the arb as intended to pump up the tyres.
Also pretty straight forward to change the settings in the SLABS unit, got a Nanocom? Or know someone who has?

The lines to the air bags are 4mm, you can buy push on fittings from any good hydraulic/truck place. They come with a 1/8 or 1/4 BSP pipe thread or if you are going to use the arb I recall them being 1/4?? So can get fitting no problem, but as said before it'd be way easier to get an original compressor!!

Cheers Lemo

I'm hunting around for a 2nd hand wabco compressor & I'll use the ARB for tyres etc. Thanks all

Update: I've got a 2nd hand Wabco and have a bagpipingandy's rebuild kit on the way. Bought 2 new conti bags for a great price.

The air lines and valve block should be ok shouldn't they, or should I redo them just in case? Same question for the filter.

There was some talk about moving the filter location, is this necessary?