I had my tyre pressures checked at Barry Shaddick Tyres at Avonmouth last week but I am going to go up to my yard tomorrow afternoon, check them all with a digital gauge and adjust them as necessary, then start taking measurements every week.
When they were checked last week the tyre fitter used a standard “garage type” pressure gauge, and I doubt that it was particularly accurate, I want to get them equalised across axles, taking a cold tyre pressure reading, and keep them that way.
What pressure would you personally run tyres at? I have 295/80.22.5 tyres on the drive and mid-lift axles and 385/65.22.5 tyres on the steer axle and they are currently all inflated to 100 psi.
I usually put 120-125psi on steers and 90-95psi on the drives. You want valve extensions on the drives for ease of pressure checking but they can sometimes be responsible for air loss and make sure everthing’s got dust caps.
Probably won’t be a consensus on this topic though I bet.
Yes, that’s what the tyre fitter did. If a truck tyre fitter doesn’t know what pressure to inflate truck tyres to, then perhaps I can be forgiven for asking on here.
Own Account Driver:
Probably won’t be a consensus on this topic though I bet.
For sure.
But probably a better place to discuss tyres than the thread about photos of lorries. That’s why I started it.
Yes, that’s what the tyre fitter did. If a truck tyre fitter doesn’t know what pressure to inflate truck tyres to, then perhaps I can be forgiven for asking on here.
Own Account Driver:
Probably won’t be a consensus on this topic though I bet.
For sure.
But probably a better place to discuss tyres than the thread about photos of lorries. That’s why I started it.
Shaddicks are definitely a specialist commercial truck tyre outfit, and I would think that’s the majority of their work, but I don’t think many operators would agree with those pressures. Possibly they just put in that as a catch-all without knowing type of work/load you’re typically on. I would have said a bit too hard on drives and way too soft on steers.
It would be very surprising but maybe the compressor on the van wouldn’t go up to much more.
I used to run the singles on the front at 115 as it made for a better ride, 105 - 110 on the rears, it really depends what work your doing in all honesty, I know of people running 90psi on the rears on site work…
Nitrogen is awesome for tyres however, how practical and expensive it is for a truck I’m not sure. It’s prime advantage over comp air is that nitrogen has all it’s molecules the same size which is usually bigger than the holes in the honeycomb effect of the tyre compound. Comp air is whatever was in the air at the time, compressed and that can be all sorts of stuff with some molecules smaller that the pores in the tyres carcass so they leak out and the tyre goes down. Nitrogen also tends to keep your tyres cooler. The main disadvantage with comp air is that very often it contains water vapour, even with a drier in the supply system and this, when heated, expands more than most other things and increases pressure quite a bit.
Tyre pressures depend very much of work operations, loads, amount of full/empty running etc. I always ask the guvner of any company I’m working for, what he suggests!
If you’re running heavy, run your tyres at 10psi over the maximum pressure marked on the sidewalls and re air them when they drop 10psi, slight over pressure will do no harm at all, whereas under inflation murders tyres and fuel economy
Nitrogen is ok, but only if it’s free, there is no benefit other than it doesn’t seep out as fast, but if you’re regularly checking your pressures it’s not hard to add a bit so the benefit of Nitrogen no longer is of any concern
Also, get your gauge calibrated properly and do it every couple of months, they go out of whack quite easily, so it’s an important step
i think tyre pressures is one thing i get paranoid about i have 295/80 all round on my unit i have had the steering lined up several times over the years but the tyres still seem to scollop out if ever i spec up a new lorry i would have super singles on the front and midlift axle as i think the ssc daf is too bigger cab for the tyre size and people who have s/singles seem to fair a lot better then me i carry 3 tyre gauges one is a dial type which being a bit of a fool i bought then found i could not fit it on the outer wheels of the back axle so i then bought a rod type gauge which fits every thing i also have a gauge on a air inflater which i can hook up to my palm couplings and pump up a tyre of my red line if it has a slow punture to get me hope just the other week i had trouble with a valve extension the lorry had gone in for a service i went and picked a trailor up at night when i done my morning checks it looked a bit soft but not to bad so i carried on when i got to the drop it looked softer still so i got my gauge out to find there was only 50pounds in it so a quick trip to the local tyre fitter for him to check it out found the valve had come loose at the thread on the inner wheel i will say when ever i get tipped and the air suspenshion is up full and u can get your had between the mudguards and the tyres i always bang all 4 tyres to see if they feel the same u can soon tell by the feel if one has less air in
newmercman:
If you’re running heavy, run your tyres at 10psi over the maximum pressure marked on the sidewalls and re air them when they drop 10psi, slight over pressure will do no harm at all, whereas under inflation murders tyres and fuel economy
^ This.
Underinflation means drag and heat and it’s the heat that does most of the damage.It’s surprising why anyone would want to go much lower on the drives as they’re already the hottest running tyres on the wagon and the last thing they need is more drag and therefore heat .
Armagedon:
As a fellow Maggie owner front 120 anymore steering is all over the place,drive 100 all seems to work fine.
I’ve been up the yard this afternoon and set the steer axle tyres to 115psi. I’ve fitted these valve caps, they are supposed to start flashing if the pressure drops by 4 psi.
I’m not sure how reliable they are but I’ll monitor the pressures every week after the weekend break when they are back down to ambient temperature. I’m using a digital tyre pressure gauge but cross-checking that against an old-stylee tyre pressure gauge, the type which pushes a steel cylinder out of a barrel,and they seem to tally with each other.
Hopefully I’ll be able to replace the offside drive axle tyres and the lift axle tyres next weekend if some money materialises and flog the remoulds on ebay or somesuch.
Armagedon:
As a fellow Maggie owner front 120 anymore steering is all over the place,drive 100 all seems to work fine.
I’ve been up the yard this afternoon and set the steer axle tyres to 115psi. I’ve fitted these valve caps, they are supposed to start flashing if the pressure drops by 4 psi.
I’m not sure how reliable they are but I’ll monitor the pressures every week after the weekend break when they are back down to ambient temperature. I’m using a digital tyre pressure gauge but cross-checking that against an old-stylee tyre pressure gauge, the type which pushes a steel cylinder out of a barrel,and they seem to tally with each other.
Those pressure monitors are worth their weight in gold.
Good thinking on changing those remoulds, ebay is a good idea, but even taking them off and throwing them in a skip will save you more money than continuing to run them
Hopefully I’ll be able to replace the offside drive axle tyres and the lift axle tyres next weekend if some money materialises and flog the remoulds on ebay or somesuch.
repton:
I have 295/80’s all round on mine and I was told 120-125 on the steers, 110ish on the lift and 85-90 on the drives.
Paul
+1
+2 & 125 psi on trailers.
Ambient air temperature can have an big effect on tyre pressure, what were the correct pressures one warm 25’c Sunday august afternoon will several lbs lower one chilly 8’c september Monday morning.
The underlying opinion in recent posts seems to be that remoulds are no good other than for lining skips with.
I have had good results using Michelin remix and Continental remoulds over the years, and am still using them. Ideally I use new on the front axle of 44T T/unit, remoulds or new on the midlift, and remoulds on the drive. For the trailer I ideally use remoulds on the front axle (as this positions seem to suffer the most kerb damage), recuts on the middle, and new or remoulds on the rear.
I can understand Harrys wanting to get the remoulds off his tractor unit as soon as he can afford it, but the correct good quality remould running at the correct pressure shouldn’t give any problems.
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