Front tyres losing pressure

Front tyres losing pressure

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Discussion

anonymous-user

Original Poster:

55 months

Friday 24th July 2015
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There is no visible reason as to why my front tyres lose 10psi a week but they do! No debris in the tread etc, the valves look ok, secure etc, is there a common reason why they could be losing pressure? I'll get them changed this weekend and assuming they can check and confirm there is nothing wrong with the rim, the problem should go away...

r11co

6,244 posts

231 months

Friday 24th July 2015
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Question - do you have stainless steel valve stems?

996TT02

3,308 posts

141 months

Friday 24th July 2015
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Take a wheel off and dunk it in a pond, bath, or wherever, with clear water. 10psi per week should show up as very slow bubbling. Of course if it's from the rim it could be leaking only (say) under cornering, so you could say that no evidence then points to the tyre-rim seal.

jeremyc

23,519 posts

285 months

Friday 24th July 2015
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Porous or cracked wheels?

What type are they: steel, alloy, magnesium, split rim, one piece, ...

evilmiyagi

127 posts

110 months

Friday 24th July 2015
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Do you go up kerbs a lot?

edit - by that I mean for parking etc.. before I require a flame suit wink

anonymous-user

Original Poster:

55 months

Friday 24th July 2015
quotequote all
They are OEM 2007 Saab 93 6 spoke alloy wheels, i cant imagine they are anything special in terms of material



I'll try the bath suggestion if the general consensus is that a 10 psi a week loss would be fairly easy to spot with bubbles!

I dont go up kerbs a lot to be hoenst as it usually lives in the garage. Its a fairly nose heavy car so they could lose pressure when cornering but as its an estate mostly used for family duties i dont corner that hard and they lost pressure when sat in the garage for a week so I dont think thats a cause ... they are 225/45/17s



Edited by anonymous-user on Friday 24th July 09:26

johnnyBv8

2,417 posts

192 months

Friday 24th July 2015
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Sometimes due to alloy corrosion/bubbling, possibly hidden on inside lip.

evilmiyagi

127 posts

110 months

Friday 24th July 2015
quotequote all
In that case, I'd nip it into a local tyre place, they will take them off for you and dunk them... They may even remove the tyre and refit it (along with resealing the rim) for a nominal fee.

toasty

7,487 posts

221 months

Friday 24th July 2015
quotequote all
I had the same on the RAV4 so got the tyres changed.

When they took the old ones off the wheels were really corroded around the bead line and the fitter said most of the pressure would have been lost through this.

A quick whizz round with a wire drill attachment and some new tyres and we've not had the problem again.

I could have all been the tyres but it might be worth visiting your local fitter to take the tyres off and check the wheels. My local place did it for free but I've used them for years.

saaby93

32,038 posts

179 months

Friday 24th July 2015
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Tell them about the leak so they'll probably clean the tyre seat
If the wheels gone porous you can take the tyre off and get it repainted on the inside
or try Ultraseal

MGJohn

10,203 posts

184 months

Friday 24th July 2015
quotequote all
Assuming there's not a small nail or something in the tyres somewhere, no need to remove wheels usually. Rim clip balance weights cause more "porous" alloy wheels than poor quality wheels.

Few folks would have anything large enough to submerge a whole wheel in water.

I use a Mist Sprayer ( couple quid from Garden Centre ) with 5% Washing up liquid added to cover all the visible parts of the wheel. Pressure escaping between rim clip damaged rim and tyre bead is soon revealed. If no sign of that then the wheel off and spray other unseen side.

Like this. That damage to the paint on the rim edge is not caused by kerbing. The outline clearly is that of a hammered in rim-clip balance weight which often scratches into bare matal and with the passing of time, road filth and rainwater corrodes that exposed metal and the air seal in the tyre-rim interface is destroyed. :~


TwistingMyMelon

6,385 posts

206 months

Friday 24th July 2015
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Porous rims, or something breaking the seal, or even a subtle puncture somewhere

A decent tyre place should identify it quickly (notice how I said decent)


KAgantua

3,887 posts

132 months

Friday 24th July 2015
quotequote all
pablo said:
They are OEM 2007 Saab 93 6 spoke alloy wheels, i cant imagine they are anything special in terms of material



I'll try the bath suggestion if the general consensus is that a 10 psi a week loss would be fairly easy to spot with bubbles!

I dont go up kerbs a lot to be hoenst as it usually lives in the garage. Its a fairly nose heavy car so they could lose pressure when cornering but as its an estate mostly used for family duties i dont corner that hard and they lost pressure when sat in the garage for a week so I dont think thats a cause ... they are 225/45/17s



Edited by pablo on Friday 24th July 09:26
funny enough my car does this too *conspiracy*

tomjol

532 posts

118 months

Friday 24th July 2015
quotequote all
toasty said:
I had the same on the RAV4 so got the tyres changed.

When they took the old ones off the wheels were really corroded around the bead line and the fitter said most of the pressure would have been lost through this.

A quick whizz round with a wire drill attachment and some new tyres and we've not had the problem again.

I could have all been the tyres but it might be worth visiting your local fitter to take the tyres off and check the wheels. My local place did it for free but I've used them for years.
Had exactly this experience yes

Poopipe

619 posts

145 months

Friday 24th July 2015
quotequote all
Have you tried tightening up the valve inserts?

Before going to the effort of pulling your wheels apart etc.