Tire pressure drops

[demetrios]

Hi all
I know the R129 is a heavy car but im having to inflate my tires every 7-10 days.
Granted i only drive it every 5-8 days but still.
I thought it was due to the crap Continentals that had seen better days and i changed them to Goodyear Eagles couple weeks ago. Today i went to drive it and tires are down to 15psi rear passenger and 11psi rear driver
Front passenger side down to 20psi. What could be the reason for this?

 

[Trickythemerc]

Cracked or porous rims, valve cores leaking, badly seated tyres on the rims.

 

[rf065]

Other than a slow puncture, it could either be leaking valves or corroded alloys.

 

[CarlPea]

Sounds deflating.

 

[tonysmb]

As it would seem both the old tyres and the newly-fitted tyres are losing pressure and assuming new tyre valves were fitted, then the most likely explanation is either porous alloys or damaged wheel edges resulting in a poor seal.

The chances of all the new tyres being faulty or badly fitted is slim. It might be worth just checking that the centre of the valves are properly tightened but you'd need the little tool to check that. Having said that, if they're new valves, it's unikely to be that.

 

[Gazwould]

Some tyre places don't clean up the inside wheel rim , so a poor seal .

 

[Supersizejim]

I would put my money on bad beeding or a cracked rim. Our British roads have become a living nightmare.

 

[demetrios]

Thanks for replies. How wpuld i check for cracked/porous alloys?

Only rears are new, fronts are the contis still but drivers side front doesnt deflate

 

[mercmancdi]

I have same problem one front and one back opposite sides , lose around 5lbs every 4 days , going to take in to get checked for slow punctures.

 

[grober]

The wheels may not be damaged or porous but simply have corroded rims where tyre bead seals to the wheel. These can often be cleaned up relatively easily. Tested easily enough with a soapy water mix brushed on round the inflated tyre / wheel edge with the wheel lying flat when off the car and look for bubbles - remember to test both inner and outer rims. .

 

[Petrol Pete]

I had this on the fronts of my car when I bought it. Very soon after buying the car I had the wheels refurbed and 4 new tyres fitted ant the pressure drop 'problem' went away.

Poor sealing on the bead or porous wheels which the new coating sorted out ? one of the 2 or both. I had already previously checked the valves for leaks with soapy water spray bottle.

 

[kid-jensen]

Try a can of Fix-a-Flat or similar, it's particularly good for slow punctures.

Thy the worst one, then do the rest if it works.

Luckily, the Pound shop are doing these now, but bizarrely for £2, so it's a cheap fix if it works.

 

[markjay]

Try a can of Fix-a-Flat or similar, it's particularly good for slow punctures.

Thy the worst one, then do the rest if it works.

Luckily, the Pound shop are doing these now, but bizarrely for £2, so it's a cheap fix if it works.

If you are referring to the 'goo-in-a-spraycan', then these are advertised as an emergency roadside repair, and not as a substitute to finding the puncture and having it professionally repaired (or the tyre replaced).

 

[Petrol Pete]

And once you use goo in your tyre most tyre shops will not repair it as they can't guarantee a good seal between the 'mushroom' plug and the inside of the tyre.

 

[kid-jensen]

We're talking slow punctures here.

If the tyre goo works, problem solved. If it doesn't, you're no worse off (except £2 light).

If it subsequently needs repairing, that's the tyre fitters problem. The goo is just one more thing for them to moan at you about. Just like the wife, they will moan at you anyway, so ignore it.

 

[PGW124]

some cheap tyre goo renders the tyre useless and unsafe at high speed

 

[kid-jensen]

What is this "high speed" of which you speak?

Not been able to do anything approaching high speed for years.....