ARB On-Board High Performance 12 Volt Twin Air Compressor (CKMTA12) install

[Bat21]

After much deliberation and decision making I decided to fit an on board air system to the 80, airing the tyres down/up makes for huge gains when driving in soft sand we so often encounter while in Morocco.

I looked at many options but in the end decided to go for ARB's CKMTA12 twin pump system.

I picked the pump up a few weeks ago from ARB in the midlands along with a rear air locker. Finding a decent location for the pump was proving a challenge. I didn't want it under the bonnet or anywhere it was going to struggle with sand/mud/water, so the obvious place was inside the truck.

While reading Caron's "The Story of Snow White - LC80 Build Thread" I spotted the ideal site to locate it. I had de plumbed the rear heater from my 80 quite some time ago so it was a simple enough task to remove.

Photo of Caron's rear heater as I forgot to take one of mine:-

With the heater removed it was time to check if the compressor would indeed fit in the location:-

A few minor adjustments were made to the rear of the space with a tapping stick, this was to provide enough clearance for the 2 x air intake filters. A piece of fuel hose was also cut along its length and inserted around the hole where the water inlet/outlet used to come in/out. This hole is going to be used to bring the heavy duty cables into the truck that feed the pumps:-

With adjustment made the twin pumps fit nicely in the newly vacated space:-

Placed the seat back on to check the clearance and all is fine, it's not clear in the photo but there is a 25mm gap between that 90 elbow and the bottom of the seat:-

The small manifold tank that you can see is so that the rear locker (and maybe front locker eventually) can be plumbed in off this tank via the two 1/8th ports. The main air line for tyres etc will then come off the 1/4 port on the right.

Over the next few days (weeks knowing me ) I will keep this thread updated with the progress on the install

 

[warrenpfo]

Very nice. I'm waiting for a good deal to come up on that exact compressor and then i will nab one. keep up the pictures.

My only concern with it being in the car is the noise when running but i have never heard one so maybe its not to loud.

 

[Chris]

Warren, nab two if it gets a better deal. Paul and I have been chatting about this unit and I think it's a neat solution. On my next truck I am not looking to run air tools like a do now. But this pump should do it anyway. I'd stick a 2 gallon tank under the floor as well. That does make sense. I have a twin pump set up now, it is noisy, but I have never been in the truck when I run it - why would I be? The tyres are outside. With a tank, you'd run lockers off stored air.

Chris

 

[warrenpfo]

Chris im thinking with kids in the car and they might be sleeping or if im with passengers its crappy weather outside and they get stuck inside the car whist i air up etc.

Its a small detail but when traveling with kids i think everything you can do to ensure they don't wake if asleep is a good thing.

Im thinking of trying to get one from the USA as they seem to be a good £120 cheaper.

 

[Chris]

Hmm, yeah, OK but I think you are on the fringes of the argument there. Airing tyres with kids asleep? And I will win the Lotto tonight too.

I know what you mean, though, only pulling your leg, but what are the alternatives? Under the bonnet is the only place you can stick one if you want it quiet. Or in a soundproofed box with forced air. You could end up over thinking and over-engineering it. Deff interested in one.

Charger arrived today thanks.

C

 

[warrenpfo]

Good to hear.

 

[stumog]

Just a thought but do these compressors not get hot and in contact with the carpet do these atb ones not get that hot then?. just a thought as i am not sure where i am going to put my compressor. mine is normally found underneath a bus so i was thinking of under the bonnet. mine is alot taller then these so i have to do something else.

 

[clivehorridge]

I have a single ARB compressor mounted under the bonnet. I use the rear heater a lot in the winter so wouldn't want to lose it. There's also plenty of room under the bonnet for me not having the turbo. I drive a lot on the mountain here and the soil is very sandy and dusty in the summer when it's very dry. I've never had a problem with getting sand in anything, but conditions are probably very diffferent for me, compared with running in the desert.


I don't use air lockers so the pump is only actuated for pumping tyres and other inflatable objects... er... paddling pool, bike tyres and such (if you were thinking on other lines!).

The pump is noisy. No point in pretending it's not. It's noisy under the bonnet. It will be noisy under the seat. It doesn't follow that the kids will wake, noises are the least thing (in my experience) that wakes kids. They build most noises into their dreams as we do, but if it's sudden and loud, then maybe...

I'm now considering making a receiver because I've plenty of room for it.

Anyway, my conclusion is that it's noisy. I don't think it matters where you put it, it will be noisy wherever it is. Good thing is it won't take long to air your tyres, so the noise will be short lived. The kids will soon go back to sleep if they're tired!

My tip is to make the plug-in air hose connector as convenient as you can. I would advise running a pipe to a fixed external point with a well fitting dust cap. Running an air line from under the bonnet isn't ideal, and I want to change my connection point location. When its windy and raining for me, it's inconvenient.

Likewise for you, you won't want to be airing up with the door or window open running an air line to a connection point under the seat, especially in the desert if it's windy or a sandstorm. The extra cost of installing a permanent line will soon be compensated for by the added convenience. Also make a good stowing place for the airline and gauge, to protect it and save it becoming tangled.


I advise to mount the connection on the front or rear bumper with a permanant line running from the pump to the fixed air-line connection point.

 

[Geert]

I'm also looking to install a compressor. If I'm right, this twin compressor is heavy enough to pump up a tire without an extra tank?
Good idea to intstall a permanent external air point.

 

[nivapilot]

Always nice to ahve an external air tank, mounted under the rear, with air line fittings.

I would mount a tank under the rear floor area, with an outlet mounted to both ends of the car, maybe on top of the bumpers? and then mount my truck air horns under the bonnet, operated via a solenoid......that's it I'm off to the scrappy for a lorry air tank.

 

[Chris]

My tank is under the passenger floor area. It's a VIAIR 2.5 gallon. The 2 gallon might have just squeezed in a little easier. I have front and rear air points.

Chris

 

[clivehorridge]

My tank is under the passenger floor area. It's a VIAIR 2.5 gallon. The 2 gallon might have just squeezed in a little easier. I have front and rear air points.

Chris

I only have the single pump and to fill a 305/70/16 takes ages. If the twin pump delivers double, then it will only take half an age, which is still too long so I'd recommend a receiver tank in any event. I was considering a modded fire extinguisher, various sizes of small gas bottles and all sorts of containers. There's nothing readily on the market here, but Chris' 2.5 gallon floor tank sounds interesting. I'd go for that if I was in the UK I think.

I like the idea of air points front and rear. I've got plenty of room under the bonnet for a sizeable tank, or under the rear floor (where the spare wheel used to be). Under the bonnet is favourite, then I could pipe air straight from the pump tee'd into the tank and then tee'd again running front and rear along the chassis near to the floor.

The rear air point could go behind the swing out rear wheel carrier (ARB) and the front could go behind the grille maybe, with a descent support bracket.

 

[Chris]

I had mine originally above the spare wheel. Yes, there is actually enough room with it in place to get a tank under there. Err, above there..Well you know what I mean.

This is where it is now, tucked up and protected by the sliders.




Air points are shrouded

Can't find a pic of it in the spare wheel area.

C

 

[Jon Wildsmith]

I know Chris has a tank so he can run air tools but otherwise why bother with a tank, it's just another thing that has to be filled with air before it starts going into your tyres? I'm a fully paid up member of the 'because I can' club but a tank is just more work for the compressor to do before it does something useful like inflating a tyre ...

 

[Chris]

Because, Jon, it stores the air you make when fiddling around with valve caps, having a swallow of tea etc and walking around the car to get tot he next tyre. Actually air comes out of the chuck as soon as you start the pumps - it doesn't somehow magically fill the tank before coming out of the pipe. Also when seating a tyre back onto the rim, you get a huge dump of air that you don't get with just a pump. It's a good way to be able to include a pressure switch too so that you don't have to click your pumps on and off all of the time. Especially if you have to keep going into the cab to reach the switch.

I have not found a down side to having a tank yet. A full tank gives you best part of a tyre full before you even get out of the vehicle.

C

 

[Jon Wildsmith]

if your tank is empty, until the pressure has equalised, the air will flow out the tyre and into the tank, only flowing back into the tyre once the pressure has equalized. With a tank you need the time spent fiddling around with valve caps just to break even and you need a big tank to take a decent size tyre from say 20 psi back to 35 psi. You can still use fixed outlets and pressure switches without a tank and the compressor doesn't have to be hard mounted, just have a quick disconnect where the compressor lives to plug it into.

 

[Chris]

No, sorry Jon, it simply doesn't work like that. At no point has the pressure in my tire gone down and filled the tank. I can appreciate the theory, but in practice, I have had this set up for the best part of three years and in Lil Blue before that. My tank will fill from empty to full at 150 psi in 1 minute and 7 seconds. As I put my pumps on before the vehicle has stopped, I have a tank full of air, before you have even opened your boot. Now, if I had some poxy little pump like a Halfords special, your point may indeed be valid. But I am knocking out somewhere over 5 CFM My tank filling tubes are actually larger than my final delivery hose too. I'd make them bigger if I could, but it means that in fact I am making air slightly faster than I am using it - probably.

It works very well indeed. I think that you'll find that in my set up, I have non return valves in the delivery side, so air never leaves the tyre unless I press the deflate button.

Chris

 

[Paul]

These are the people i am looking at for a system to go in the 80.

http://www.aironboard.com.au/online/

 

[Jon Wildsmith]

I'm not going to bother arguing about it with you Chris, that's spoiling Pauls thread while you try to disprove what cleverer blokes than me figured out a long time ago. I asked the simple question why bother with a tank in most cases? I think you make my point for me, delete the tank in your install and your pumps shift so much air there wouldn't be a lot of difference in how fast you can pump the tyres up.

 

[Chris]

Jon I'd hate you to think of this as an argument it's more a healthy debate but you asked the question "why bother?" And I am giving the readers the benefit of my practical experience. If that doesn't match what se clever chap wrote in a book the I can't help that. I think far from ruining the thread it adds very important information
I wouldn't want people to think they must fit a tank so an objective voice is always important. Paul and I have been chatting for se time about my set up and he has a tank to fit. Maybe he doesn't need to bother
I think a lot of this depends on the set up and the pump characteristics or 'curve' as it were. Mine produce good air and rather than waste that potential when not extracting it I can store it and get the benefit. But I am airing 37s from 15 psi to 45 not simply topping them up for a trip to Tesco.
Ok not everyone wants or needs a tank including yourself. But there ARE benefits from having one. I could very easily put in a T bypass that I have and simply go direct to the chuck if needs be

I get you point about tyre pressure but when my tyre is at 15 psi to start with the pump is producing more than that from the off. Added to which the one way system doesn't allow the tyre to actually deflate. My experience therefore is that my tyre pressures go up immediately. So do others judging by the queue that usually forms to borrow it.

I feel there probably is an optimum tank size for each system and certainly not clever enough to have worked that out.
But I can say that once my tank is 'depleted' the tyre pressure continues to rise with the pumps running.

Hope that's helpful to anyone thinking about a tank - or not

Chris