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Tyre Pressures???"


ricpop
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I'm trying to find out the correct tyre pressures for my 2003 Lunar Zenith 4 - tyre size 175 13 C (printed on the tyre). The owners handbook that came with the van covers every model except the Lunar Zenith 4. Amaizingly a phonecall to Lunar revealed how hopeless these companies are at after sales- they hadnt a clue :angry: So can anyone out there help me, at present Ive blown them up to 42 psi which seems to be a good average for the available information in various caravan diy books. :rolleyes:

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Guest john1215

ricpop,

 

Yes the max on the sidewall is too high for towing. The last few vans I've owned seemed to have tyre pressures between 45-50 psi.

 

john1215

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As with a car - the optimum cold pressure will vary with the load carried.

 

Having said that, apart from caravanners, most of whom do many checks before venturing on the road with their precious van, how many motorists vary the tyre pressures to suit whether they are driving solo or fully loaded.

 

It's like many other things in life we select an 'average'.

 

I made the warning re the max because of 'idiots' reading the post. That is the SAFE max pressure that the tyre was manufactered to contend with.

 

I have a small 5' x 4' trailer that I use primarily for transporting junk to the 'tip'.

 

When I'm carrying hard-core etc. the tyre pressures are at 65psi (max).

 

After the trailer has been emptied - if I didn't let most of the pressure out to about 30psi - it would bounce about all over the road like a pea on a drum.

 

ATVB

 

Keep SAFE.

 

ps always carry a 12 volt pump in the car which even though it has its own gauge I check with a digital one.

You can not reason with an unreasonable person.

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The recommended tyre pressure is usually given by the manufacturer in the handbook or on the caravan plate. The will vary from caravan to caravan depending on the weight and the tyre size. The pressure stated on the tyre is the maxium permitted, which is normally well above the recommended pressure. The load on a twin axle, is normally less (per tyre) than on a single axle caravan and thus pressures are likely to be lower. If you intend to travel at high speeds in hot climates it might be prudent to increase the pressures slightly.

 

Brian

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Surely the effect of being in a hot climate and travelling at high speed will increase the pressure of a correctly inflated tyre anyway?

14414[/snapback]

 

Yes it will, but tyre pressures are always checked and set cold. I am not talking about a large increase in pressure, say 2-3psi or 10% max. Higher pressures will reduce the amount of heat build up and hence reduce the risk of a blow out. The same recommendations are usually found on car tyre pressures for the same reason. The downside maybe that caravan might more "bouncy" , but I don't think you would notice a small increase in pressure.

 

I have known people have blow outs and they always seem to occur in hot weather. Apart from loss of stability on a blow out, damage often occurs to the caravan wheel arch due to tyre shredding, so a failure can be an expensive business.

 

Brian

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I have blown mine up to 52psi which is a good bit more than they were. I'm off next week to Devon via the M5 hopefully it will be OK. I must admit that the original pressure 32 psithe tyres were a bit flat looking, now they look ok.

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  • 4 weeks later...

Have had my tyres at 52psi for a couple of trips now and everything seems fine so I bought a couple of those tyre pressure indicator dust caps set at 52 psi, they certainly take the guess work out of checking tyres and only a fiver a pair.

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at present i own a 04 chateau 450 (changing to zeneth 5 next month) the van came with no manual but the tyre pressure's are marked above the wheel arch 4. 50 bar (64 psi) this is the max pressure (cold) marked on the tyre wall - the tyres where set at around 54 psi.

 

I pumped the tyres up to 64 psi and it did tow a lot better - seamed to be more stable at 60 mph - again having no manual on the van is a pain, have got some manuals on various things in the van i. e fridge and heater - oh and one on the oven which is in every language but english!!!

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ps always carry a 12 volt pump in the car which even though it has its own gauge I check with a digital one.

14398[/snapback]

 

I would like to back up what Phil says. I have a 2. 4m box-bodied twin axle trailer; when empty, I drop the pressures down to stop it skittering - once loaded I pump them up. Empty, it weighs almost nothing, but it is rated for the best part of a tonne and I've had it loaded close to that several times.

 

I don't vary the tyre pressures in the caravan because it almost always travels at a fairly constant weight.

 

In the caravan, I carry a small 12V powered tyre inflator (which also does airbeds etc.), a basic pressure guage, and a Kamasa extending wheelnut wrench - just in case. Since I sometimes lend out the trailer, that too has an extending wheelnut wrench and a cheap footpump, stored with the spare wheel.

 

I have a decent electric pump, wheelnut wrench, and a good quality digital pressure guage in the car; and I do change my car tyre pressures depending on load, temperature and road conditions. If you always have the kit handy in the boot, and are practised at using it, it becomes easy and familar to do.

 

I'll admit to being a bit paranoid . ... but I prefer to think of myself as "Well-orgainsed" !

 

:)

 

JAF

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Ive towed a couple of times now with the tyres at 52 psi which is a good bit higher than the original 36 psi. The van is more stable and seems to have lost its 'bounce' so I'm happy. I also carry everything I need, electric pump, trolley jack, axle stands, in fact the caravan is better equipped than the house, as to the handbooks, the one Ive got is for the lunar range not the Zenith and covers every model except the Zenith (good eh!) Each model it does cover has completely different settings for everything including tyres, theres no standardization between models let alone makes.

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on the subject of tyres, does anyone know if the letter rating after ther last number relates to the speed rating as on car tyres

 

ie

 

155-R13-82T

 

what is the T rating for ???

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The letter indicates the max speed rating of the tyre at rated loading

 

Take a look at this

 

Briaan

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Dont know where I managed to dig up the "T" thing from, mine are actually "82R"

 

so from what im reading, R= upto 106 mph

 

and the 82 bit = upto 1047lbs (just need to do the sums now to Kgs)

 

Reason im getting into all this is my tyres have been on this van since I got it, I have no idea how old they actually are, so im thinking its got to be worth replacing them

 

Tyres are 155-R13-82R

 

Caravan max laden weight is 950kgs

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