Thumper Twin Air Compressor install

[Chris Burke]

I would be worried with water ingress ruining it if mounted under the car. I have one of those compressors and it is no where near the most sealed of units, especially around the casing that the internal wiring and motor sits behind.

 

[Silveredition]

I would be worried with water ingress ruining it if mounted under the car. I have one of those compressors and it is no where near the most sealed of units, especially around the casing that the internal wiring and motor sits behind.

Yep - it very well might be buggered very soon, but I am committed to give it a crack!

I stripped it again, and separated the circuit board to mount this in the engine bay, and removed (cut out) the aluminium housing. I still need to cut off the carry handle. I flipped the motor so the drain hole and wiring enter on the underside instead of both being on the top. I think I will seal everything up with some sort of automotive / marine sealant...
One thing I have noticed is that the compressor is trying to suck all of its air in through the interference-fit chrome plastic filter caps. I don’t think this would help its performance... also, where the air enters is right on the join between a felt ‘washer’ and the foam filter - not such a great design....
No warranty now!!

 

[Pubski]

if you use an inflater on the end of the hose that has a trigger it will read accuratly when you let go of the trigger.
and then you should be able to rely on the pressure switch built into the compressor

somthing like this should do the job then you can leave the compressor on the whole time you are inflating your tyres

View attachment 52664

This is all conditional on the hose being strong enough to manage the pressure that the compressor gets up to prior to its cutout switch activating.

This is what I've been using on mine works well. Only issues iv'e had with mine mounted under seat is the speedflow 90 fitting coming loose on a track. And the self reseting circuit breaker tripping. Only trips when pumping up tyres though thinking of just pissing it off completely.

 

[Chris Burke]

I have thought a few times about mounting mine but it really isn't a hassle for me keeping it in the bag, throwing it in the ute when going out on a trip and getting it out and connecting it to the battery when filling tyres. The ute is stationary anyways and would have to get the hose and stuff out anyways if it was mounted.
Little different if you were using it to fill a reservoir and run air lockers and such.

 

[Pubski]

I have limited room in the discovery theyre not big cars so freeing up draw space was the main reason just so happened days after i installed i broke my. Rear diff so fitted locker and changed it to suit

 

[Batts88]

I have limited room in the discovery theyre not big cars so freeing up draw space was the main reason just so happened days after i installed i broke my. Rear diff so fitted locker and changed it to suit

When I had a TD5 I fitted the compressor in the left hand rear box they aren't much good for anything else except for storing towels or rags.

 

[Pubski]

When I had a TD5 I fitted the compressor in the left hand rear box they aren't much good for anything else except for storing towels or rags.

Mines a D1 tdi so theres even less room i have custom draws in the back. I have a sub down one side and spare parts and oil down the other,You gotta fill every crevice in a Discovery

 

[Silveredition]

Well, I nearly stuffed it!! I tried to encase the circuit board in 2 pack resin, but something went wrong - either too much hardener (but I doubt it) or the resin reacted with the CRC soft seal that I coated on the circuit board first. It got too hot to touch, and then the resin started cracking as it was going off... to my surprise, I managed to remove the circuit board from the resin (it was already set hard, but could be cracked and torn off). I wrecked 2 wires, but can easily re-solder these... this is what is left of the resin..

I temporarily re-wired the compressor to the circuit board and it still works - phew!!
I am thinking if I have any issues with the circuit board I will get rid of it and use a single relay. I am unsure of why it has such involved wiring???... also, it seems to be switched through the -ve as the +ve runs straight to the battery and the only wire going into or out of the circuit board is the -ve... is this normal?

 

[CruisingSned]

Hope you get compressor sorted. My thumper max arrived today and thinking of doing something similar.
Automotive I've found tends to be a bit all over the place. I'm from an industrial/automation background and it is generally the positive that is switched.
I think the twin relays are there to handle the current. If the supply is in series it will half the load between the 2 relays, effectively giving you 180A switching. I can't tell from looking at your photo and hope i haven't confused you.

 

[Marck]

That resin is fairly thick it would generate plenty of heat setting. Maybe try a specific potting compound if that’s not what you have tried already. Something like this

https://au.rs-online.com/web/p/potting-compounds/1991474/

 

[Silveredition]

It was West Systems epoxy. I have used it plenty of times before without it generating such heat... I have now made a marine ply tray and will use Sikaflex automotive adhesive / sealant to waterproof and stick it to the ply....
Will get there one day!!

 

[CruisingSned]

Just a random thought silver edition. Would it be worth having a metal IP66 enclosure mounted underneath with compressor and running a vent tube with filter inside the cabin?
At least the metal enclosure would allow some heat dissipation.
Most nylon glands are IP66 and not overly expensive. Should be able to get glands to fit hose as well as cable

 

[Silveredition]

Test fit of mounting cradle...

 

[Silveredition]

FINALLY finished!! I did what turned out to be a ‘test’ mount as I then had to cut off and move one of the mounting positions, and add more bracing. I ran air hose with a Nitto fitting to the rear of the car, and worked out the wiring of the additional rear demister switch. Now I turn the compressor ‘on’ with the dash switch. The compressor will run for about 3 seconds until the pressure in the hose reaches 120psi, then the compressor will stop. When going between tyres the compressor isn’t running - hopefully this will help slightly with cooling - and the quietness it certainly nice!!! Now to try it out for a while and see how long it lasts!!

 

[Marck]

That looks tidy well done. Have told thought of putting a mesh screen around it to try keep it a bit cleaner ?

 

[Silveredition]

A couple of days back I had the opportunity to try out the compressor in the situation that I went to all the effort for... Down the bottom of Exmouth Gulf - car tyres and boat trailer tyres getting pumped up as quick as possible in temps over 40 degrees... I found out a couple of things...
1 - it is quick!
2 - it doesn’t like getting to the 120psi cut out.. each time it cut out (after the first 2 tyres) I would have to turn the dash switch off and on again for the compressor to re-start... If I left the air flowing through the hose and the compressor continuously running it was fine..
3 - once I was finished all tyres I unplugged the hose from the rear bar and the Narva 120amp circuit breaker tripped... a few minutes later it re-set and all was good... Once again as it hit the 120psi cut out...

I have my Thomas Bluetongue with me and will continue to do so until I have some confidence in the Thumper... (this may be never!!)

 

[CruisingSned]

Silver edition
I think the 120 psi cutout is protection for the compressor. It' only there to stop the compressor component from self destructing.
The electric motor has a maximum draw of 90A. By tripping the 120A breaker twice in quick succession (I read post correctly?) You have electrically run the motor to its limits. The other issue is the electric motor Will have residual heat from first trip and as such Will draw more current and trip. It would require a cooling period to prevent damage
I think you need a control system and a small receiver tank
The idea would be to switch motor off at 80 (at a guess) and back on 70psi. This would keep motor and compressor away from operating limits
The other way could be to extend the on/off switch on a lead attached to your hose and switch it on when required..
Hope this helps and doesn't sound condescending
I used my thumper max to air up 31's from 20 to 35psi by turning on/off and had no problem.
Any question PM.

 

[CruisingSned]

I've got no affiliation with 4x4 supercentre..

 

[Silveredition]

Silver edition
I think the 120 psi cutout is protection for the compressor. It' only there to stop the compressor component from self destructing.
The electric motor has a maximum draw of 90A. By tripping the 120A breaker twice in quick succession (I read post correctly?) You have electrically run the motor to its limits. The other issue is the electric motor Will have residual heat from first trip and as such Will draw more current and trip. It would require a cooling period to prevent damage
I think you need a control system and a small receiver tank
The idea would be to switch motor off at 80 (at a guess) and back on 70psi. This would keep motor and compressor away from operating limits
The other way could be to extend the on/off switch on a lead attached to your hose and switch it on when required..
Hope this helps and doesn't sound condescending
I used my thumper max to air up 31's from 20 to 35psi by turning on/off and had no problem.
Any question PM.

Thanks mate,
The 120A circuit breaker only tripped once (which is once too many...). The other times it was just the dash switch that needed to be turned off and back on after the compressor reached the 120psi cut out to get it to re-start.... I am unsure of why this occurred...
I might look at the 80psi pressure switch (or lower) - or just change the hose fittings so air is always free-flowing through the hose...

 

[CruisingSned]

Awesome.
Nice 60 series by the way!