# Air Ride (Autocruise) - possible GVW uprating issue



## loughrigg (Nov 10, 2008)

I'm trying to find some information on the system fitted to my Wentworth (2002 model).

Unfortunately, the original MH handbook is missing but I have managed to get hold of a copy from Swift that appears to be the correct version. That handbook identifies the system as:

Kuhn Auto Technik PnuemaLift PL-FB 8 overload pnuematic springs

and gives some very basic info on recommended driving pressure (1.5 bar) and maximum pressure for parking (7 bar).

I have managed to get hold of a technical manual fron Kuhn - but, unfortunately it is in German.

If anyone out there can provide additional info/documentation, I'd be grateful.

Thanks

Mike


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## ingram (May 12, 2005)

I have this system fitted on my 2006 Starblazer. I too have little information but I do have an installation instruction sheet somewhere but it is fairly incomprehensible: seems mainly to deal with modifying /adjusting the rear brake compensator. I can scan and send to you if you like.

As I understand it; adjusting the pressure when parked will raise / lower the rear end to assist with levelling: not tried it yet: you do of course need to have some type of compressor or pump.

I would also be interested in any further information. 

Was there anything specific information that you wanted to know about it?

Harvey


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## drcotts (Feb 23, 2006)

Hi Mike

This system as similar to the "air-ride" system fitted by a company called airride who sill exist.
The main use of these air springs is to give better handling whilst driving as they reduce the side to side movement. They also improve the overall driving as the vehicle remains more level when loaded to max.
They can also be used to level the van generally if there is more weigh on the one side. 

the disadvantage will be the quality of the ride in respect to road noise as they will stiffen the rear suspension and as a consequence you will get a boom boom boom whenever you go over the speed reduction slats at the approach to islands and speed humps.

Its a case of finding the best pressure for your particular set up. We currently have 2.5 bar in each bag.

Dont use them as an excuse to overload your van as they are not designed to allow this. for a start the brakes and tyres wont handle it.

the fitter should have adjusted the brake compensater when fitting them as they defeat the compensator when used because they raise a loaded van up in the air and the braking system then thinks the van isnt loaded as much (because its riding higher) and so diverts the braking efficiency away from the rear wheels. The effect is that you can get into a skid if theb compensator isnt adjusted. i am assuming that Autocruise have fitted and ajusted the compensator correctly. i hope they have as i have the same can as you. :roll:


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## loughrigg (Nov 10, 2008)

ingram said:


> I have this system fitted on my 2006 Starblazer. I too have little information but I do have an installation instruction sheet somewhere but it is fairly incomprehensible: seems mainly to deal with modifying /adjusting the rear brake compensator. I can scan and send to you if you like.
> 
> As I understand it; adjusting the pressure when parked will raise / lower the rear end to assist with levelling: not tried it yet: you do of course need to have some type of compressor or pump.
> 
> ...


Thanks Harvey.

This Kuhn system appears to be still in use in more or less the same configuration as existed in 2000 - 2002 (or perhaps hasn't been superceded by something vastly better/different).

Initially, I thought the system was an Aurocruise fit and that their dealers would (before their demise) have been aware of the system and able to service/repair it. However, it seem likely (from the Kuhn company website) that it could be a Peugeot factory fitted item. I've left a question with a couple of Peugeot main agents to see if they have anything on it.

I've tried O'Leary Motorhomes (who bought up most of the Autocruise parts) and Swift but neither have any documentation.

I think your description of the system fits with what I've found out (recommended driving/max pressures (1.5 bar / 7 bar) ; use for levelling and/or stiffening when parked). I think it can be adjusted using the same 12v compressor I use for my car tyres, but I haven't tried that out yet.

For what its worth this is the company website showing what appears to be a very similar system:

http://www.kuhn-autotechnik.de/ehtm/start.htm

If you could let me have a copy of your instruction sheet, it might come in handy at some point. I'll try to PM my email address.

If I find anything useful I'll pass it on.

Mike


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## loughrigg (Nov 10, 2008)

drcotts said:


> Hi Mike
> 
> This system as similar to the "air-ride" system fitted by a company called airride who sill exist.
> The main use of these air springs is to give better handling whilst driving as they reduce the side to side movement. They also improve the overall driving as the vehicle remains more level when loaded to max.
> ...


Hi Phill

I get the impression that its not the sort of system that gets adjusted very often. I think you'd have to have a pretty uneven pitch or a very bouncy (parked) back end to pump it up to 7 bar.

Did you adjust it to 2.5 bar or was it set by a dealer/fitter? Do you know what type of pump fits?

Ultimately, I'd like to be able to have enough information to be able to get an appropriate fitter to check the compensator adjustment if it seems necessary. Finding out who fitted it would be a good start!

If I find anything relevant, I'll pass it on.

Mike

Mike


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## loughrigg (Nov 10, 2008)

It now looks like this was an Autocruise fitted item. According to Peugeot my base vehicle left the factory as a chassis cab or pick-up with standard suspension.

Any other Autocruise owners out there with this piece of kit fitted?

Mike


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## ingram (May 12, 2005)

loughrigg said:


> It now looks like this was an Autocruise fitted item.
> 
> Mike


Yes it was. I have an approval certificate for mine. It was installed by:-

LVS ( Leisure Vehicle Supplies Ltd )
Unit 39, Rumer Hill Business Estate
Cannock.
Staffs.

It is to upgrade the suspension for an increase of GVW. In the case of my Starblazer, from 3500kg to 4150kg. There is also a new rating plate overlay under the bonnet.

My Autocruise manual says the pressure should be between 1 and 2 bar.

The KUHN installation sheet says the driving pressure should be either 2bar or 1.5 bar depending on which model of overload spring is fitted. I don't have any documents which tell me which I have...................

Harvey


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## loughrigg (Nov 10, 2008)

ingram said:


> loughrigg said:
> 
> 
> > It now looks like this was an Autocruise fitted item.
> ...


I'm beginning to wish I hadn't started this.

None of the documentation I have seen (including the rating plate under the bonnet) suggests that the GVW has been uprated from the weight listed in the handbook - 3,400kg.

I suppose its possible that the uprating was done but the process didn't get as far as generating/fitting a new plate?

The question is where do I get a definitive answer from?

Any guidance appreciated.

Mike


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## pneumatician (May 1, 2005)

*Airride/Firestone/Dunlop Suspension*

As I understand it they are all basically the same principle. 
A pair of pneumatic bellows/cylinders fitted between the Chassis and rear axle.
You adjust the pressure to improve drive stability and comfort.
I have the Dunlop system on my current vehicle (Marcle Leisure) and the Firestone on the last one. Both fitted DIY.

I would suggest you increase the pressure in small increments untill you find the optimum settings for your van. Ours is 30 psi or 2bar.
Be carefull if you use a compressor they do not take a great volume and you could split the bellows if overpressurised. I use a bicycle pump.

They do not increase your rear axle loading or carrying capacity.

Steve


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## grumpyman (Sep 24, 2006)

When I purchased my Pioneer Autocruise there was paper work concerning these Pneumalift bellows (PL-FB8). The paper work I have tells you what tools are required and how to fit them.
I did not think they were fitted to mine but I only took a quick look underneath and never gave it another thought.
What the paper work also states is if you have the PL-FB6 fitted the pressure should be 2 bar if PL-FB8 1.5 bar. and you should only alter the pressure for manoeuvring purposes eg. driving onto a Ferry to a max of 7 bar. Apart from looking underneath for 2 bellows is there anything else i should look for as it describes work being done on the dashboard. Anyone want a copy of what i have is welcome 4 double sides sheets.
Would have to be Sunday or Monday off in the Van this weekend.


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## loughrigg (Nov 10, 2008)

*Re: Airride/Firestone/Dunlop Suspension*



pneumatician said:


> As I understand it they are all basically the same principle.
> A pair of pneumatic bellows/cylinders fitted between the Chassis and rear axle.
> You adjust the pressure to improve drive stability and comfort.
> I have the Dunlop system on my current vehicle (Marcle Leisure) and the Firestone on the last one. Both fitted DIY.
> ...


Hi Steve

Thanks for the tips - I'll be careful when adjusting the pressure (if I use it, the compressor I've got is fairly low powered with a digital cut-out).

It doesn't sound like your MH has had its GVW uprated - am I right?

Mike


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## loughrigg (Nov 10, 2008)

grumpyman said:


> When I purchased my Pioneer Autocruise there was paper work concerning these Pneumalift bellows (PL-FB8). The paper work I have tells you what tools are required and how to fit them.
> I did not think they were fitted to mine but I only took a quick look underneath and never gave it another thought.
> What the paper work also states is if you have the PL-FB6 fitted the pressure should be 2 bar if PL-FB8 1.5 bar. and you should only alter the pressure for manoeuvring purposes eg. driving onto a Ferry to a max of 7 bar. Apart from looking underneath for 2 bellows is there anything else i should look for as it describes work being done on the dashboard. Anyone want a copy of what i have is welcome 4 double sides sheets.
> Would have to be Sunday or Monday off in the Van this weekend.


All I have seen on my Wentworth are the fittings shown in the photographs on the manufacturers website

http://www.kuhn-autotechnik.de/ehtm/start.htm (follow the link through products to supplementary pnuematic springs)

I've not spotted anything on the dashboard - the pressure dials/valves are on the vertical surfaces low down immediately behind the two cab seats.

If you could let me have copies of your documentation, I'd appreciate it (I'll PM email/fax number).

Thanks

Mike


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## ingram (May 12, 2005)

Mike,

I have just sent you 7 pages of the Kuhn documents that I have.

The reference in them to dashboard dials is only an instruction as to where they should be fitted if they are fitted there.

My dials and valves are behind the passenger seat.

It could be that this suspension was fitted to your Wentworth without a weight upgrade. Sometimes air suspension is fitted just to improve ride and handling. I do however have a 2006 catalogue with the Wentworth in it and it says the GVW is 4150. That doesn't mean it necessarily is for a 2002 model though.*** See my next post below.

Harvey


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## ingram (May 12, 2005)

*** Having now read the text in the 2006 brochure I can tell you that it says that the Wentworth is upgraded for 2006 with a heavy duty chassis providing a dramatic increase in the maximum user payload.

So you can stop worrying. You don't have missing paperwork or plates. Sorry I wrote about that and gave you reason for concern  

It seems likely that your suspension upgrade may just have been for the comfort handling reason and could even have been retro-fitted. As the UK agents for KUHN, or one of them, seem to be LVS maybe they fitted it and can tell you details of it.

Harvey


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## loughrigg (Nov 10, 2008)

ingram said:


> *** Having now read the text in the 2006 brochure I can tell you that it says that the Wentworth is upgraded for 2006 with a heavy duty chassis providing a dramatic increase in the maximum user payload.
> 
> So you can stop worrying. You don't have missing paperwork or plates. Sorry I wrote about that and gave you reason for concern
> 
> ...


Thanks Harvey

I'll have a look at the docs you sent and possibly have a chat with LVS.

I guess one of the drawbacks in being third owner of an MH is that various bits of paperwork can easily be mislaid as the vehicle passes throught he hands of successive owners/dealers.

Thanks for your help.

Mike


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## pneumatician (May 1, 2005)

*Airride/Firestone/Dunlop Suspension*

Mike,

No my van was not uprated. 
But please remember Air springs do not increase the load carrying capacity. They are only to improve the handling and ride.

Idid try and get my last van, an Autosleeper uprated but when AVT looked into it they said it had already been increased from 3T to 3.2T and I would have to find out from AS what mods had been carried out.
I asked them and the response was a deadly silence no one at AS volunteered any information. I came to the conclusion right or wrong that no mods had been carried out. I will never know.

Steve


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## loughrigg (Nov 10, 2008)

*Re: Airride/Firestone/Dunlop Suspension*



pneumatician said:


> Mike,
> 
> No my van was not uprated.
> But please remember Air springs do not increase the load carrying capacity. They are only to improve the handling and ride.
> ...


Hi Steve

I've come to much the same conclusion - in the absence of any evidence to the contrary, I'm taking it that my MH has the original GVW.

Even though the payload is not huge, I'm not looking for any extra capacity as it is only a two berth and should be more than adequate for the touring I have in mind.

Thanks for your help.

Mike


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## ingram (May 12, 2005)

*Re: Airride/Firestone/Dunlop Suspension*



pneumatician said:


> Mike,
> 
> But please remember Air springs do not increase the load carrying capacity. They are only to improve the handling and ride.
> 
> Steve


That is not strictly true. That is exactly what they are for on my Autocruise. To legally increase the load carrying capacity / GVW the correct certification is required of course and it should not be assumed that just fitting air springs allows you to carry heavier loads than your motorhome is rated for: but air springs can increase the load carrying capacity.

Harvey


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## dcoups (Aug 11, 2014)

Hi

anybody out there can you help I have Kuhn PL-FB8 fitted on my autocruise set at 1.5 bar but backend too high any ideas?


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## loughrigg (Nov 10, 2008)

Hi

That is the system on my Autocruise, so I'll help if I can.

What makes you say the backend is too high? I tend to drive with the pressure at around 1.5 bar, although it does occasionally drop a little below that. If pressure falls below 1.3 bar, then the suspension can start to bang if the road is uneven.

Mike


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## dcoups (Aug 11, 2014)

Hi Mike

thanks for quick reply. body is still too high at 1.5 bar even on level ground whole body not level it feels like walking down hill inside. when I look at other mh body is level. system has adjustment each side of seats both on 1.5 bar could it be set too high. Some posts I have read say between 1.0 to 2.0 bar


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## peribro (Sep 6, 2009)

Air suspension isn't really about adjusting the height of the vehicle so that it's level - it's more about providing a better ride and better cornering. Some vans are inherently nose down as was my last one - an Autotrail Cherokee. Despite air suspension I still had to use ramps under the front wheels if parking on a level surface.


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## loughrigg (Nov 10, 2008)

dcoups said:


> Hi Mike
> 
> thanks for quick reply. body is still too high at 1.5 bar even on level ground whole body not level it feels like walking down hill inside. when I look at other mh body is level. system has adjustment each side of seats both on 1.5 bar could it be set too high. Some posts I have read say between 1.0 to 2.0 bar


I'd endorse what Peribro says - the air suspension is mainly about improving ride. On my Wentworth, if I deflate the airbags completely, the back end is more or less resting on the suspension bump stops, so driving anywhere is noisy and uncomfortable. With no inflation, my MH looks slightly down at the back, so the opposite effect that you have.

Once you are parked up, you can either use ramps at the front or deflate the air bags a bit (or both) to help level things up. On a very uneven pitch, I did once use a combination of ramps and airbags to level the floor - I think I had one side around 1 bar and the opposite side around 5 bar - but it was only an overnight stop.

Whatever you do with the airbag pressures, do make sure you put them back to the driving level before setting off - a mechanic did once inflate my airbags way too high without asking (or telling me what he had done). The first corner after leaving the garage involved some scary fishtailing.

Best of luck

Mike


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