radicalrev

iTrader: (2)

Firstly, i just got my rims powdercoated, installed new valve stems and reinstalled the tires about 1 week ago.

Yesterday night (didn't drive all day) I realized that my front driver side tires seemed flat and went to the gas station (5 blocks away) and inflate all my tires to 40-42 PSI.

Today, i checked the driver side tire and it was 33 PSI and the passanger side is 41 PSI. So i went to the same gas station and inflate the driver side to 40 PSI.

Got home during lunch time checked and it was 41.5 PSI (due to heat).

Just few minutes ago (6.30PM) , i checked it again, the driver side is 37 PSI and the passenger side is still 41 PSI.

I feel like it is losing tire pressure slowly like 0.5 PSI/Hour.

So I took the wheel out to check the tires but to find no signs of nails whatsoever.

I suspect it was the new valve stems but I sprayed soapy water and found no sign that it was the valve stems.

Any other possibilities?

Maybe the new powdercoated wheels? I had no problems before getting them powdercoated.

Thanks guys for any help.

mitsuguy

iTrader: (2)

couple options...

I'll start with most likely...

most likely is a nail you can't see... possibly the head has fallen off, and its been embedded in the tire so much you can't distinguish it... solution: get a big something to put water in and hold the tire under water and look for the bubbles...

I actually don't think you'll find any punctures, but ya gotta start there, and start with a thorough inspection... just looking at it isn't good enough...

If it's not your typical puncture, then my guess is one of two things, though if I had to bet money, it'd be that when the tires were dismounted, that one was damaged in the bead area... the other possibility, though less likely, is that the powder coating is kinda shoddy in places (maybe places you don't even see), that is letting air escape between the power coating and the original metal of the wheel....

alright, back to my original bet... on many tires, unless you are very careful, you will tear the bead during dismounting... this torn bead is typically enough to allow the tire to be mounted, but not good enough to keep air in.... I have a feeling if you had that tire opened up, you would notice a chunk missing from the inside bead on the tire... only recourse is to dunk it and look for leaks, and as necessary, replace...

it also might not leak air from this section of tire unless there is weight on it at just the right place (so it would effectively only lose air on the rotation of the tire)... However, same as the puncture, you should dunk it in water and look for bubbles...

radicalrev

iTrader: (2)

YES! i do notice when they dismount the tire, they took so much force and having a hard time taking the tires out off the rims. Some rubber came off but didnt know what it was and I thought it wasnt a big deal.

That might be the problem.

Thanks alot bro!!

mitsuguy

iTrader: (2)

make them replace your tire... they damaged it beyond repair... they will try to use some sealer on it, but it is never a permanent solution.... it'll get you out of their hair for a week or two, maybe a month, but the problem will come back...

they owe you a tire...

radicalrev

iTrader: (2)

thanks!! really appreciate your help!

radicalrev

iTrader: (2)

so when to the tire shop and they put it under the water thing...i saw small tiny bubbles coming out from the side of the rims...

Mitsuguy you are right, it should be the bead of the tires.

So i say bla bla bla to persuade the owner to replace it.

But he says that the bead sealer would fix this problem and if not he will replace it.

So yeah, hopefully this works and i won't have a blow out today on the freeway.

Thanks again!

mitsuguy

iTrader: (2)

Even if it is sealed and no longer leaks, that tire is now at a much higher risk of having a sidewall separation / blowout...

before, when the tire was in good shape, the bead was completely covered in rubber and the inner liner that holds the air pressure in a tire... now that the bead is torn, the rubber is no longer isolating the air inside the tire from the cords that run around the bead... because this inner liner is not there, air is able to seep into the cords of the tire and will eventually make its way up into the sidewall of the tire, which will cause an air pocket... we used to say the tire was "pregnant" every tire I've ever seen with a sidewall bubble like that has been because of damage to the bead area of a tire... we always sent them in for credit as a defect, but many times they were sent straight back to be disposed of with no credit given...

that tire is literally ruined...

mitsuguy

iTrader: (2)

oh, and the reason it did that was they either used the wrong dismount head on the machine, the machine wasn't designed to work properly with larger diameter, low profile tires / wheels, or they didn't use enough lubrication... instead of the tire sliding, the rubber gripped... gripping rubber tears...

GS2006

Speaking of the right machine or machine head: I have noticed no matter how careful the tire tech is there is always slight digs or scratches around the rim lip when they remove a low profile from an alloy rim that has a clear coat on it. These rims finish are very soft. I have seen how those specialty guys put on a 30” tire and they don’t even try doing it from the front side of the rim. I also have seen these high dollar machines that do not use those pry bars but have not seen any of those around here. It is very annoying.

Many years ago when I worked in a gas station we used to see old tires come in on steal rims with huge bubbles in the side wall. When we would take the tire off the rim the rim would be all rusted, bead all rusted and cord would be exposed because of the rubber being all rotted. Once it is torn, it would be suspect of any sealer keeping out the moisture keep the air pressure where it belongs. The cord it exposed, it a disaster waiting to happen. Even though RMA does approve some repair, you should ask for replacement.

radicalrev

iTrader: (2)

Thank all for the advice. I will keep on monitoring my tire pressure every 4 hours and if it loses psi, I will definitely ask for a replacement. I will keep uguys updated if something else happen.

mitsuguy

iTrader: (2)

All tire machines need at least one pry bar - whether manual or automatic, to at least dismount the tire... when mounting a tire there is little chance to do damage to a wheel unless you are a complete idiot... and then, most damage is done when mounting the tire on the backside of the wheel...

the design of the wheel is what dictates how the tire is mounted though (whether from front side or back side) Reverse mount wheels (typically wheels with big lips) have the drop center closer to the back of the wheel, necessitating install from the back of the wheel... normal wheels have the drop center closer to the front of the wheel, making you have to install from the front side...

when mounting low profile tires on a normal wheel, all of the metal to metal contact is done in an area that you can't see with the tire mounted... on low profile tires on reverse wheels, special protectors have to be used to clamp the wheel to the machine, however, if these are worn out, they may still do significant damage to the front lip of the wheel...

dismounting a tire is a whole different story, but you still pretty much have to be an idiot to damage a wheel... normal wheels do have the chance of the pry bar leaving a small indentation even with the best of tire techs, however a bad tire tech can really do some damage to the lip if the tire slides around much... reverse mount wheels, same type of potential for damage to the lip if the protectors are not used or not in good condition, but dismounting a tire this way is pretty fool proof - any scratches would be hidden on the back of the wheel...

most of the damage to a wheel is done trying to mount it on the machine... specifically reverse mount wheels when trying to remove a tire... you use the bead loosener shoe to loosen both sides, but because it is probably a low profile tire, the tire doesn't move a whole lot - this means it is hard to get the clamps between the tire and wheel... if you miss, the metal part of the clamp can leave a nice gouge across the lip... some are much harder than others... typically the tire that is too wide or at the higher range of approved tire width to rim width is the tire that is much harder to remove safely... narrow tires or tires with soft sidewalls succumb to the bead loosener much more readily...

for the record, I have mounted 26" tires and wheels with nothing more than a pair of prybars and a pretty standard tire machine with adapters to hold the larger diameter wheel... at the same time, all the fancy gadgets they build on to tire machines are pretty useless to a seasoned tech - any time one of my guys was having an issue with a low profile tire, I'd swoop in, push the "helper tools" out of the way, grab two bars and slide the tire right on, never a scratch... but thats experience, and companies can't typically afford to pay for that good of experience

radicalrev

iTrader: (2)

^ well said.

I wish I can find shops like you run in Socal.

GS2006

This is the type of tire install on a 30” wheel I’m referring to:
http://www.youtube.com/watch?v=U-Uzs...om=PL&index=13

If this was my wheel, I would cringe. In this video you will see him slip with one bar. If that was the front, I’m sure it would of left a big big mark..

If they would pry like that on my rim it would leave all kinds of marks, dents and gouges.

This is a hunter demo, when that bar leaves that lip attachment it would leave a mark on my wheel.

http://www.hunter.com/pub/product/vi...ndex2.cfm?v=21

I have two types of marks on my wheels and I’m not happy about it.
1) light scratches from that lip tool from when the machine rotates the wheel. Maybe the machine is old and when they bar is pulled over it bends down the lip attachment and it makes contact with rim. Maybe they should use extra rubber inserts between the lip attachment and the rim?? These scratches are very very light but are there.

2) Marks that have chipped the clear coat and paint/primer on the lip. Not sure how these happened, but can only suspect it happened when the pry bar comes off the lip attachment as shown in the hunter video. However, I have seen some that move that rotate the tire in the opposite direction and the bar stays on the lip attachment. These are the marks that really irk me. I would prefer they use a nylon wrapped bar, but I only saw them do that on a couple of the rims. Not sure why they only did that on a couple??

I watched them and they were careful and they new I was concerned about damage/scratches. I even gave them a nylon coated socket to remove the lug nuts.

The machines that were used this last time look pretty warn out to me. Are you saying you can remove the tire on one of these rims without leaving any marks at all? I sure would like to find someone that could do it. Been through several rounds and I have not found one yet.

What type of machine did you use at your shop? I think these were rim clamp. Dealer used a hunter.

And I'm with the other poster, it would be nice if all tire techs could do a change with out marks.
Thanks

mitsuguy

iTrader: (2)

their machines at DT get 2-3x the amount of usage they were ever designed for per day/week/month... for the most part, they either work or they don't, and their condition typically has nothing to do with what happens to the wheel... those are the same machines I love to use - very very simple... they are the Coats rim clamps, typically the 7050 and 7060 (these have the extra little arm that can help sometimes, however the older 5040's work just as good for me, I also prefer the pneumatically operated turntable, not the electric turn table - they have more power though and are easier to damage a tire with, but they work better IMO)... I don't like the Hunter machines when it comes to tire changers, though I prefer their balancers...

Anyways, they should have a nylon protector for the pry bar so that when it slides off the dismount head, the nylon hits the edge of the wheel - this thing still leaves a little mark on some wheels, but doesn't chip the wheel... leaving bare metal certainly can obviously... the things that we are looking for wear on is the nylon dismount head - over many tire changes, tire dismount lube gets stuck to it, and stuck in the lube is small dust and sand and grit that can really do a number on a nice pretty finish... also, for reverse mount wheels, there are nylon protectors that go over each of the clamps - however, on a soft painted wheel, these will sometimes scratch the wheel regardless how good of condition they are in - solution - take a shop rag, fold it in half a couple times and use it as an insulator between the clamp and the wheel - it sometimes makes it harder to mount/dismount the tire because the wheel can spin a little more freely inside the clamps, but its ok - it virtually guarantees no damage, just a little more work...

on that 30" wheel, that is pretty typical because of its size - it just doesn't fit on most tire changers period... the big lip on it is why they mount it from the back, but yes, in this video, its pretty clear they were having a tough time with it... the hardest tire I ever mounted was some 335/30-20's and 275/35-19's on some CCW wheels (20x14 rear, 19x10 front).... the barrel on the CCW's doesn't let the tire slide all the way down, and it was a pain in the *** to do... this was definitely one of those I didn't want my techs doing, if I screwed it up, I would only have to yell at myself... Anyways, $6000 for the wheels, $1800 for the tires, going on a tubbed out 67 Camaro...

I set up the deal, manager at the time questioned me if we'd be able to get it done... of course I said yes, and there was no way after I said yes that he was going to let an 1800 sale walk out the door... ordered the tires in, customer waited with the wheels while I installed... he saw how careful I was and that they were a bit tougher than the average tire to mount... long story short, he tipped me $100... I tried not to take it, but he insisted, so I bought the shop lunch with it... he said he felt he got lucky with someone dedicated to taking care of people and their possessions...

radicalrev

iTrader: (2)

guys i have a quick question. I found a really good deal on Continental tires which have the same size as my front ones. a pair of 225/35/19 have 85% thread left for $135.

Should I go for it to keep these for spares just in case? Btw, all 4 of my tire size are 225/35/19. So it would be spares for both front and rear.

But my rears are Toyo T1Rs and totally different thread pattern. Which i know usually people recommend me to have the all 4 tires at least same thread pattern.