80 PSI tyre pump

[hallii]

Any suggestions for a good 12v pump able to reach 80PSIin less than 2 hours?

 

Hallii

[Mickt]

Just wondering why you need a pump to go to 80psi. If it,s to pump van tyres to this presure then you are probably over inflating them .

[Corky 8]

Have a look here it may help you decide for yourself, if you have a costco card they are doing a good one at £24+,

http://www.theultimatefinish.co.uk/Store/Content/Default.aspx?PageId=2

[Derek Uzzell]

Earlier pump-related discussions on the following thread

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=21050&posts=18

 

that itself contains a link to an even earlier thread that itself contains links....

[Brian Kirby]

Another here: http://tinyurl.com/324wl5x

[mirage]

I should think your fillings will drop out at 80 psi keep the money for the dentist.

[Derek Uzzell]

Corky 8 - 2010-11-27 5:57 PM

Have a look here it may help you decide for yourself, if you have a costco card they are doing a good one at £24+,

http://www.theultimatefinish.co.uk/Store/Content/Default.aspx?PageId=2

This is a useful link as it allows a comparison of the pumps' air-flow rate (the higher the better).I note that there is an error in the data for the Ring RAC-800 pump. This is a 12V/230V rechargeable pump and its air-flow rates are 28 litres-per-minute in 'compressor mode' (ie. when pumping up a tyre) and 44L/min (NOT 440L/min!) when in 'inflator mode' (eg. when inflating an air-bed).The Ring RAC-700 pump (which I have) apparently has an air-flow rate of 36L/min

[JohnP]

This is what I use for bike, car and motorhome. Delivery from Wiggle is quick and reliable.

 

http://www.wiggle.co.uk/p/cycle/7/Topeak_Joe_Blow_Sport_Track_Pump/5360013205/

[Colin Leake]

The 80 PSI you are looking for comes from the Fiat or Motorhome hand book. I have no idea why they do this other than it is the maximum pressure recommended for the tyres. Send an email to the tyre manufacturer with the front and rear axle loadings and they will send you the correct tyre pressures. For our Rapido running on Michelin's it is 60 PSI all round and this is fairly typical for motorhomes below the 3,500 KG limit. Running at too higher pressure will give you a very hard ride, high tyre wear in the middle of the tread, reduce grip and handling and because of the shock loadings knock the living daylights out of you suspension components, bushes and wheel bearings etc.

[Derek Uzzell]

Colin Leake - 2010-11-28 10:53 AM

 

The 80 PSI you are looking for comes from the Fiat or Motorhome hand book. I have no idea why they do this other than it is the maximum pressure recommended for the tyres. Send an email to the tyre manufacturer with the front and rear axle loadings and they will send you the correct tyre pressures. For our Rapido running on Michelin's it is 60 PSI all round and this is fairly typical for motorhomes below the 3,500 KG limit. Running at too higher pressure will give you a very hard ride, high tyre wear in the middle of the tread, reduce grip and handling and because of the shock loadings knock the living daylights out of you suspension components, bushes and wheel bearings etc.

 

The reason 80psi is regularly recommended goes right back to when Michelin's XC Camping pattern was the only tyre that specifically targeted the motorhome market. For XC Camping, Michelin used to advise "For maximum load conditions when used on mainland Europe it is recommended that the rear tyres are inflated to a pressure of 80psi".

 

However, if a motorhome owner weighed his/her motorhome and discovered that the "maximum load conditions" caveat did not apply, Michelin were prepared to offer inflation-pressure advice based on axle-load data provided by the motorhome owner.

 

When I last checked, Michelin would no longer do this. If you asked for inflation-pressure recommendations for 'camping-car' tyres and provided axle-load data, Michelin would give you a front-tyre pressure relating to the front axle-load datum, but would advise 80psi for the rear tyres irrespective of the axle-load.

 

One thing is certain, if Hallii uses 80psi in the tyres (hopefully camping-car tyres!!) of a Transit-based motorhome the ride will be very hard.

[terryW]

Asked the CCC technical team about 12 months ago and they said so far they had not found one. The problem is not the pressure but the capacity and run time.

 

Most specify a max run time of 15 minutes to allow cooling and don't do much in that time

 

Burnt out 2 so far so now I won't have a van without a well inflated spare.

[Andy_C]

mirage - 2010-11-27 7:44 PM

 

I should think your fillings will drop out at 80 psi keep the money for the dentist.

Of course it does depend on the van & the tyres. Mine run at 65-70 psi front and 75-80 psi on the rear...

 

Andy

[Corky 8]

Does anyone have a Burstner without a spare Wheel ? as Burstner supply the Motorhome with a tyre inflator and a sealant Pack, which I surmise would be a special supply to Burstner, but up to the job of inflating the Vehicle tyre, If anyone does have such an inflator,could you l Please let us know the model name and number, I had one with our 08 Burstner but never took that much notice to it having bought a spare wheel and tyre,  Thanks for any info,

[Brian Kirby]

Two additional points. 

First, these inflaters seem generally to be aimed at adjusting the pressure in a tyre, and not at inflating it to its working pressure from a flat condition.  The exception might be the Ring RAC 900, but the current drawn exceeds the normal output from the ciggy lighter, and it must be connected directly to the battery.

Second, according to my Transit Owner's Handbook, 80PSI exceeds the maximum pressure recommended by Ford for the Transit (max 69psi for all variants of Mk 7 Transit, although the Hobby Handbook cites 5.5 bar (80psi) (quoting Ford as the source, but only for Michelin XC Camping tyres) and I think 80 psi may also exceed (or is very close to) the maximum working pressure for the type of "high pressure snap-in" valve that Ford tend to fit.  (Our van in on standard Continental Vancos, so the lower pressure applies.)

So, if Halli is inflating his tyres to 80psi, unless the valves have been replaced with metal stemmed bolt-in valves, I'd suggest he stops, at least until the 80psi figure is checked and confirmed correct by all concerned!  At present, an error somewhere seems possible.

[hallii]

Thanks all for the replies, from what I have read I think I will go with a good old fashioned foot pump, maybe a Michelin one and a seperate digi pressure gauge.

 

My tyres are Continental Camping and the maxium pressure is shown as 80 psi, but I have noted the comments about the maximum pressure for the valve stems.

 

My book tells me that the rear tyre pressures should be 69 psi, but I said 80 psi so as to give a small margin, rarely does anything work well at it's maximum.

 

I had a flat tyre on my last Spanish outing, and had to change the wheel, I was able to get the puncture repaired quickly so it was not a problem. I would like to be able to inflate a flat tyre to working pressure, it might just enable me to get to a tyre place for repairs.

 

I remember having two caravan tyre punctures within an hour of each other, the foot pump came in handy that day!

 

I have got a set of metal valve stems from an ebay link on this forum, I must get them fitted, I have actually had a rubber stem split on my VW T4 (now long gone).

 

Well that's my Christmas pressie list sorted!

 

Hallii

[hallii]

Thanks all for the replies, from what I have read I think I will go with a good old fashioned foot pump, maybe a Michelin one and a seperate digi pressure gauge.

 

My tyres are Continental Camping and the maxium pressure is shown as 80 psi, but I have noted the comments about the maximum pressure for the valve stems.

 

My book tells me that the rear tyre pressures should be 69 psi, but I said 80 psi so as to give a small margin, rarely does anything work well at it's maximum.

 

I had a flat tyre on my last Spanish outing, and had to change the wheel, I was able to get the puncture repaired quickly so it was not a problem. I would like to be able to inflate a flat tyre to working pressure, it might just enable me to get to a tyre place for repairs.

 

I remember having two caravan tyre punctures within an hour of each other, the foot pump came in handy that day!

 

I have got a set of metal valve stems from an ebay link on this forum, I must get them fitted, I have actually had a rubber stem split on my VW T4 (now long gone).

 

Well that's my Christmas pressie list sorted!

 

Hallii

[Derek Uzzell]

Brian Kirby - 2010-11-28 1:06 PM

Two additional points. 

First, these inflaters seem generally to be aimed at adjusting the pressure in a tyre, and not at inflating it to its working pressure from a flat condition.  The exception might be the Ring RAC 900, but the current drawn exceeds the normal output from the ciggy lighter, and it must be connected directly to the battery.

Second, according to my Transit Owner's Handbook, 80PSI exceeds the maximum pressure recommended by Ford for the Transit (max 69psi for all variants of Mk 7 Transit, although the Hobby Handbook cites 5.5 bar (80psi) (quoting Ford as the source, but only for Michelin XC Camping tyres) and I think 80 psi may also exceed (or is very close to) the maximum working pressure for the type of "high pressure snap-in" valve that Ford tend to fit.  (Our van in on standard Continental Vancos, so the lower pressure applies.)

So, if Halli is inflating his tyres to 80psi, unless the valves have been replaced with metal stemmed bolt-in valves, I'd suggest he stops, at least until the 80psi figure is checked and confirmed correct by all concerned!  At present, an error somewhere seems possible.

I'm fairly confident my Ring RAC-700 pump could happily inflate one of my Hobby's 215/75 R16C tyres from 0psi to, say, the 65psi I keep the spare-wheel at, but that pump needs a 12V supply fused to a minimum of 15A which is more than many dashboard 12V sockets.I'd be very wary of Hobby's handbook advice. As I've said several times before on this forum, when the Transit Mk 6 3500kg platform-cab chassis was first made available to selected motorhome manufacturers in 2004 most of those manufacturers chose to have Michelin XC Camping tyres fitted.Whether there was a massive communications failure at that point, or just pig-headed cluelessness, the result was that Ford factory-fitted a data-plate to all these chassis advising a rear-tyre pressure of 80psi irrespective of the tyres on the chassis being XC Camping (designed to be able to handle 80psi) or ordinary light-commercial-vehicle (with a maximum design-pressure not exceeding 70psi).My 2005 Hobby has ordinary LCV Continental Vanco-8 tyres and, when I realised that the advice on the vehicle's Ford data-plate conflicted with those tyres, I contacted Ford(UK) about this. Ford(UK) were supremely uninterested, but other people must have highlighted the conflict as an informed Ford specialist later told me that revised data-plates (with much lower rear-tyre pressure recommendations) had been provided for those Transit platform-cab chassis that had not been fitted with 'camping-car' tyres as original equipment.As far as I'm aware, Ford has never fitted bolt-in valves to Transits as original equipment. The wheels on all Mk 6 platform-cab chassis had traditional high-pressure snap-in valves as shown on the following webpagehttp://www.balanceweights.co.uk/category-s/3.htmThese should be good for at least 80ps inflation pressure, but there was a disturbing number of unexplained failures to which Ford turned a blind eye. (There continue to be reports of tyre-valve failure on Transit Mk 6-based motorhomes that, presumably, still have the factory-fitted valves.) Mk 7 Transits (the current model) have a snap-in valve with a completely different design that looks near bomb-proof. I can't find on-line any technical details of this valve, so I can't say what its pressure tolerance is. As I've never read any complaints of tyre valves failing on Mk 7s (LCVs or motorhomes) I assume it's problem-free. As Ford don't fit bolt-in valves to Transits, even if a Transit-based motorhome has, say, Michelin 'camping-car' tyres and the owner wants to follow Michelin's advice to use 80psi in the rear tyres, Ford are highly unlikely to recommend (or authorise) the fitting of bolt-in valves instead of the HP snap-in tyre-valve on Fords's own parts list.

[Brian Kirby]

True Derek, but when the time comes for tyre changes, it is fairly normal for folk to go to the usual outlets, rather than a Ford dealer, and for them to install new valves along with the new tyres. 

It hasn't got to that point with ours yet, so I don't know what valves the fitters would install, but I wonder if they would necessarily go for the particular valve Ford has adopted, or might just take a "standard" HP snap-in from the bin. 

That might leave folk back where you were, with your original valves, that weren't really up to the job.  There seems only to be one standard for HP snap-in valves, so presumably all types are equal, even if some are more equal than others!  If I'm correct, this still seems an unsatisfactory situation.

Regarding Ford UK, their technical dept has a rather unhelpful attitude to anything to do with Transit platform cab derived vehicles.  The basic response I got being "not made here, mate", seemingly because Ford UK doesn't bring in the platform cab chassis and the only examples are found under imported motorhomes, and also that mine had a different "Flax Pack" than the UK version, and all the technical details (for mine) were in German, for which they had no translation (so leaving me at a loss to understand how they knew the Flex Pack content differed).  I tried pointing out that the chassis was made by Ford, and they were called Ford, but that didn't work either!

[Derek Uzzell]

Brian Kirby - 2010-11-28 3:33 PM

True Derek, but when the time comes for tyre changes, it is fairly normal for folk to go to the usual outlets, rather than a Ford dealer, and for them to install new valves along with the new tyres. 

It hasn't got to that point with ours yet, so I don't know what valves the fitters would install, but I wonder if they would necessarily go for the particular valve Ford has adopted, or might just take a "standard" HP snap-in from the bin. 

That might leave folk back where you were, with your original valves, that weren't really up to the job.  There seems only to be one standard for HP snap-in valves, so presumably all types are equal, even if some are more equal than others!  If I'm correct, this still seems an unsatisfactory situation.

Regarding Ford UK, their technical dept has a rather unhelpful attitude to anything to do with Transit platform cab derived vehicles.  The basic response I got being "not made here, mate", seemingly because Ford UK doesn't bring in the platform cab chassis and the only examples are found under imported motorhomes, and also that mine had a different "Flax Pack" than the UK version, and all the technical details (for mine) were in German, for which they had no translation (so leaving me at a loss to understand how they knew the Flex Pack content differed).  I tried pointing out that the chassis was made by Ford, and they were called Ford, but that didn't work either!

Ford issued an OASIS instruction about the 'correct' valve to be used on Transits that require high-pressure tyre valves. However, I don't know how reliably such instructions arrive at tyre-fitting outlets. When I asked about that particular OASIS instruction at a local ATS branch the fitter I spoke to replied on the lines of "We could well have had it, but I don't remember anything about it."You may recall that, when HP tyre-valve failures on Transit Mk 6-based motorcaravans began to be reported on motorhome forums, I asked all three tyre-fitting firms in my area whether they knew about this and they all did. Worryingly, they had all perversely chosen to fit standard non-HP valves as replacements as they had 'taken against' HP valves generally as a consequence of the Transit ones failing.So, regarding your para 2, there's every chance a fitter won't install the valve Ford specifies in the OASIS instruction unless that tyre-fitting firm specialises in Transits and keeps them in stock. There's also a sporting chance that the fitter won't install an HP valve at all if the customer is uninformed about the need for this.I have never been able to establish satiisfactorily why the tyre-valves on my Hobby failed, but I know these failures didn't just happen to motorhomes. With no useful data to work with there's no point in theorising and, having replaced all the original valves with bolt-in ones, I know that particular problem won't re-occur. The TR600HP valves that were fitted as OE to Mk 6 Transits are not a specialised design (and they weren't/aren't just used on Transits). According to their markings my Hobby's valves were made in Germany, but many companies manufacture TR600HPs including Schrader. This is a 'standard' HP snap-in valve design and there's no reason to think that they should have been problematical and fail the way they did. However, the snap-in valve now used on Mk 7s is nothing like a TR600HP and (as I mentioned earlier) I've never been able to identify its maker (Not that I've broken my heart trying!)Although the following refers to non-HP snap-in valves being used on LCVs, it still makes interesting reading:http://tinyurl.com/39uwzsbIf you get into German motorhome forums, it's evident that tyre-valve related problems have been well discussed over time. The consensus is that snap-in valves just sholudn't be allowed for motorhome wheels and, having had two snap-in HP valves fail in the same afternoon and in an identical manner, I can fully support that view.The Transit platform-cab chassis is merely a panel-van to which the guys in Ford's Turkish factory have forgotten to fit the sides, roof and rear panels. When I gave my Germany-sourced Hobby's VIN to a local Ford agent he seemed to be able to retrieve its technical specification easily enough. Perhaps things will be better with the FWD chassis-cab with Auto-Trail/Tribute building motorhomes on it in the UK. Then again, perhaps not!

[Derek Uzzell]

hallii - 2010-11-28 2:12 PM

 

Thanks all for the replies, from what I have read I think I will go with a good old fashioned foot pump, maybe a Michelin one and a seperate digi pressure gauge...

 

Hallii

 

Before committing to the foot-pump route, I suggest you refer to the following article:

 

http://www.autoexpress.co.uk/products/products/56696/foot_pumps.html

 

Although the report is 5 years old, it's worth noting the test criteria. These were a) the accuracy of a pump's own gauge at 30psi and b) the increase in pressure in psi that a pump was able to produce with 50 'strokes'.

 

50 strokes of the best pump could add 12psi, but don't forget that the tyre being inflated during the test was an ordinary car tyre and that only relatively low pressures were involved. It would be completely unrealistic to expect that pump to be capable of inflating one of your motorhome's tyres from 0psi to 69psi with 288 strokes. (Even if it could, that's still a helluva lot of strokes.)

 

Inflating at 30psi is one thing: inflating at 60psi quite another. I've owned 12V tyre-pumps that have inflated the tyres of my cars easily and rapidly from, say, 25psi to 30psi, but have either refused to work at all, or took forever, when asked to put a couple of psi into a motorhome tyre at 60psi.

 

In June 2010 MMM published a tyre-pump article that, besides reporting on various 12V pumps, included testing of a track-bicycle pump and a twin-barrel foot-pump.

 

The comment for the former was "The pump itself was fast and it did work... I did turn purple with the effort, though...it will work in an emergency, but you may have a heart attack in the process."

 

Comments on the foot-pump included "...As it approached the 60psi mark, it got quite tricky to pump and your humble tester thought he might pass out..."

 

I suggest you ask Santa to bring you a Ring RAC-900 12V pump and a good quality dial-type analogue pressure-gauge (no batteries to fail).

 

Personally (even though I know you've already bought some bolt-in valves) I wouldn't bother to have them fitted until your motorhome's tyres require replacement.

 

The TR600HP snap-in valves factory-fitted to Mk 6 Transits and the valves factory-fitted to Mk 7s are pictured in this MHF thread.

 

http://www.motorhomefacts.com/ftopic-20551.html

 

The differences will be obvious and the likelihood of a factory-fitted Transit Mk 7 tyre-valve splitting or disintegrating have got to be minimal.

 

 

[Uncle Bulgaria]

Derek Uzzell - 2010-11-28 10:59 AM

 

When I last checked, Michelin would no longer do this. If you asked for inflation-pressure recommendations for 'camping-car' tyres and provided axle-load data, Michelin would give you a front-tyre pressure relating to the front axle-load datum, but would advise 80psi for the rear tyres irrespective of the axle-load.

 

 

I found the same the last time I contacted Michelin in May this year. I sent them the fully laden weighbridge axle loads. Here is their reply:

 

"Thank you for your recent e-mail.

 

We suggest that individual axle weights from weigh scale readings are used, in order to calculate pressure recommendations for each quoted load condition. These would be preferred, due to readings being taken in the actual vehicle 'running' condition - that is to say, with all water/fuel/baggage & passengers etc. onboard - and may result in better comfort if the vehicle is running way below maximum capacity.

 

The results of roadside surveys indicate that some motor homes have been found to be over laden, especially the rear axle, with potential for subsequent tyre related problems.

 

The overall tyre industry, therefore, tries to build-in a safety factor by fitting strong tyres, inflated to high pressure, in order to remove the potential for consequences of overloading &/or under-inflating the tyres.

 

The drawback of this safety factor, at the corresponding high pressure, may be an extremely hard ride. The contents of the motor home may rattle, but the tyres will cope nicely.

 

One 'overall' weight is of no use in calculating tyre inflation pressure levels, since the vehicle may appear to be within the maximum permitted, but in reality may have the rear axle severely over laden & the front axle very lightly laden.

 

As a guideline from the axle weights that you have supplied on tyre size 225/75 R16 CP and being the Agilis Camping, the pressures for those weights are as follows:-

 

Front axle load of 2000kg the pressure should be – 55psi (pounds per square inch) per tyre

Rear axle load of 2200kg the pressure should be – 80psi (pounds per square inch) per tyre

 

You would be advised to follow the manufacturers recommended pressures, indicated on the fuel cap / door-pillar / vehicle handbook in relation to the tyre size fitted – specifications can change without our knowledge. "

 

So, Michelin encourage you to weigh your motohome, but, because some motorhomes have been found to have an overloaded back axle, they will now only quote the tyre design maximum pressure for the back axle. The loads I gave Michelin were the plated maximun axle loads for my motorhome. The tyres are good for 2500kg at 80 psi. The typical laden running loads are 1800kg and 2000kg (it has a MAM of 4000kg). Michelin are ducking out of providing advice to motorhome owners who take the correct action and measure actual laden axle loads as a basis for setting tyre pressures. We know the danger of underinflated tyres - overheating/blowout, but over-inflated tyres also bring risks due to reduced contact footprint between tyre and road surface, resulting in less grip for cornering and braking. Michelin should respond properly to enquiries about tyre pressures and stop this cop-out.

 

Richard.

[Brian Kirby]

If you go to the TyreSafe website, here: http://tinyurl.com/ygj67lm you can download an information booklet entitled TyreSafe Motorhome Tyres.   This gives generic information on appropriate tyre pressures for load for a number of common light commercial vehicle tyres sizes.  The information includes  a "Load/Pressure table for specialised motorhome (CP) tyres".  Tyre markings are also illustrated and explained.  If you then go to http://tinyurl.com/2deffcs you should find both Michelin and Continental listed, among others.  Apply your axle loads to the tables, read off the appropriate pressures, and the go back to the manufacturer concerned, and invite him to resile from the published information.

My experience was that they then said the published information, having been produced by their trade association, was supported as correct by their company.  In the unlikely event they say it is not, ask them why they haven't inserted a condition, or disclaimer, in the above document.  If nothing else it will make them think a bit, and it may make you feel better, but I would expect the result to be that they do, in fact, accept the published data as acceptable to use.

[Derek Uzzell]

Uncle Bulgaria - 2010-11-29 11:47 AM

 

...Michelin are ducking out of providing advice to motorhome owners who take the correct action and measure actual laden axle loads as a basis for setting tyre pressures. We know the danger of underinflated tyres - overheating/blowout, but over-inflated tyres also bring risks due to reduced contact footprint between tyre and road surface, resulting in less grip for cornering and braking. Michelin should respond properly to enquiries about tyre pressures and stop this cop-out.

 

Richard.

 

If you read Mike Chapman's postings on this earlier forum-thread

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=15438&posts=19

 

you'll see that Michelin's stance was based on their understanding of instructions from ETRTO (European Tyre and Rim Technical Organisation) regarding 'camping-car' tyres like Michelin's own "Agilis Camping".

 

If you ask Michelin for advice on tyre-pressures against axle-loadings for Michelin NON-camping-car tyres, they will provide them to you.

 

If you ask Michelin for advice about Michelin camping-car tyres, they'll recommend front-axle tyre-pressures that relate to measured axle-loadings and 80psi for the rear tyres. They aren't doing this out of bloody-mindedness - it's because they believe (rightly or wrongly) that they are obliged by ETRTO to do this.

 

If ETRTO's instructions are ambiguous (or overly rigid), then that's really not Michelin's fault.