broken air suspension, outback australia.....HELP!!!!

[hardro33]

my family and I (wife three year old and myself)are currently travelling outback north western Australia. our air suspension on the P93 TD has broken and i need a replacement asap. The compressor was overworked, (we think) and the overheat sensor never worked ( we think) so the compressor got very hot and melted the plastic unit that attatches to it and lost pressure through the hole. the compressor still works but the piston gets very hot very quick under load?? is this normal or the start of the fault?? I have managed to pump the rear up again by cutting an old innertube up and using the valve, jubilee clipped to some pipe, fixed on to the air suspension hoses. I have pumped it up to 125 psi with my tyre compressor(thats the max it will inflate to) and its holding.....just!. We are heading slowly for Darwin (still over 1000kms away). our internet is very limited. we hope to source a replacement part asap and get it shipped to Darwin. The unit is a Wabco and it has a hand written code of 884 009 0520 (probably pinzgauer code). I write this message before searching internet myself for part, as we have such limited signal its hit and miss if we get online. Any help for sourcing this part (basically all in the black box in passenger footwell) would be greatly appreciated. also any information on how the system works would be helpfull. thanks to all the enthusiasts out there and by the way its our first serious problem in over 15,000 miles here!!
Regards
the Hardings

[Profpinz]

G'Day Mate,
Well with your vehicle that makes two TD's in Oz, and as one is a 718, spares for a 716 are vitually non existant here.
You could probably utilise a compressor from a P38 Range Rover (or equivalent) or stick with an aftermarket unit such as a Bluetongue, but your best bet if you want original parts is to import them directly.
S-Tec usually get parts to me fairly quickly (a week or so)
Sorry not to be of more help.

[hardro33]

thanks profpinz,
i dont mind importing the unit but I am having difficulty finding one as yet, my inernet connection is very hit and miss and i dont have a proper part number for Wabco or Pinzgauer.
regards
Ty

[Profpinz]

I have an early P85 TD Spare Parts Catalogue which shows a 12 and 24 volt compressor, but neither is a Wabco unit, so the details below may not be of any assistance, still they are listed as:

12 volt: Delco 12 volt _ Pinzgauer No: 716.1.54.104.0
24 volt: BDW-TYP 7530/24 volt _ Pinzgauer No: 716.1.54.441.0

[David Dunn]

If you belong to the Yahoo TD group, the manual is here.
http://f1.grp.yahoofs.com/v1/EKEtToKEt5 ... Manual.pdf

The air suspension is a simple system and shouldn't be cycling much once the truck has pumped itself up after startup. I suspect you had a leak and are destroying the pump by going way over it's duty cycle rating. You may also have the truck overloaded. The leveling switch only see the position of the rear axle and decides if it needs more or less air to stay within it's limits.

The system in my 716 was modified by the Sweds with heavier springs all around and the compressor has only come on twice in 9 years. It also has a schrader valve coming off it, I assume for manually adding air in case of pump failure ( never needed it, never paid any attention to it)

[hardro33]

thanks for the parts numbers i will look into it profpinz. will check manual on yahoo groups thanks. will try to keep you updated with progress.
Ty

[David Dunn]

TA 165 through 168 is the rear suspension sections.
http://f1.grp.yahoofs.com/v1/gAMuTv6kD1 ... %20214.pdf

[hardro33]

No schrader valve on mine im afraid! and cant get your link to work at moment. thanks for all the help will keep you posted.
Ty

[fesm_ndt]

This is the version I model, which I think are Bosch



This is version II which is possibly Wabco (I forgot about these)


This is a Viair. I think they are pretty solid and are late model equipment

[Tads]

The Viair unit is current spec and is what you'd get from Stech if you bought a replacement as the Wabco unit isn't available anymore. If you have the circuit diagram it shouldn't be hard to fab a bracket to hold a replacement compressor and rewire it correctly. Note the Viair unit needs an uprated relay (in the fuse/relay panel accessed to the right of the dash).

Do you have any idea what rear axle weight you're running? 125psi static air pressure is pushing the limits of the air suspension.....

Tom

[fesm_ndt]

Do you have any idea what rear axle weight you're running? 125psi static air pressure is pushing the limits of the air suspension.....

Tom

G'Day Tom, Their camper is one of those wide body 716 ex MoD ambulances. Did they do anything different on the suspension?

I have heard some people have fitted front springs on the rear, given the extra weight I wonder if this is a long term solution as I have not heard anything negative about doing this. Anyone else got experience of fitting the heavier front springs on the rear??

[Tads]

UK MOD-spec 4x4s have changes to the air suspension due to problems found with stone fragments puncturing air springs during the original acceptance trials. AFAIK the changes were:

1. Higher rate rear coil spring - think the new springs had green/gold markings, part number will start 758
2. Different length spring pivot pins (the pin that screws into the axle that the lower spring seat pivots on)
3. Changes to the finish of the air spring damper to try to prevent crud sticking to the bag

I've never seen one of the SDP UK ambulance vehicles up close as there were only 4? built for the trials that resulted in the Land Rover 127 Marshalls bodied vehicles being procured. As a result I don't know if there were any special modifications for this variant.

I'm fairly sure the rating of the air spring itself was unchanged and the proof pressure for the bag is (from memory) 10bar (145psi) so 125psi static pressure doesn't leave much margin for dynamic conditions.

[fesm_ndt]

I was figuring the extra large box would be a lot of weight in itself.

Only 4. I guess that explains that you don't see many around

[hardro33]

Wow!!
So gratefull for all the help and information guys. I have a few options now. first i need to lose some weight out the rear!!! I may go for the expensive "xmod" thats available as I think it will save me rewiring ( not my strong point) but we are carefully on way to Darwin, on tarmac now and nursing the pinz with fingers crossed. once in Darwin I have Internet access 24-7 and will study the information you have all supplied before deciding the best approach.
A huge pat on the backs to you lot. ( if you had seen our faces, 1000km from Darwin and still in the Bush! you would realise how grateful we are for the advice!)
Its very reassuring to know your out there.
I will keep you all posted
Many thanks
Tyron and Family

[fesm_ndt]

You may want to discuss with gregor about putting front springs on the rear and if he has a spare pair

My logic is:

- I this is a common fix on airbag assisted vehicles as although airbags are nice and smooth they are a pita
- it has been done before on a few 716
- you will always have a lot of weight in the back as a camper so a bit of extra stiffness is not going to be an issue like in an unladen stock 716
- if you keep the original springs you can always swap it back but my gut feeling is that this is a viableviiable option