Ah, absolutely brilliant. I find that after having the new tyres put onto the BBS RMs I've just refurbished, one of the tyres at the front keeps losing pressure (and the car is not being driven either). I put masses of high modulus sealant underneath the outer rim before bolting it on and then a layer on the back. I can't believe there's a leak. Gutted ( Unless it's the outer tyre seal of course, or the valve (they used my original one). Any way of seeing where the leak is? My hearing is very crap so I'll never hear it. Washing up liquid smeared over to see where it bubbles? Will that work?
Stick it in a big bucket of water trev - that's what they do down the tyre dealers to track a leak. Just make sure you dry 'em thoroughly - woudln;t want to see all that hard work go missing !!!........... Won't fairy liquid make them go dull ??
Could be the tyre is incorrectly sealed on the rim all they do is break the bead / seal between tyre and rim and inflate it again, this has happened to me a few times and only takes two ticks to fix Out of interest did you clean up the back face of the polished lip? if this is covered in the black stuff you find there it can cause a poor seal between rim and tyre Pete Edited by: Peter
Fairy liquid in water, spray it on the rim - that's how I used to check for gas leaks. Well, either that or I did it with a lighter.....
Yeah we spent a good while wire brushing the inside face of the lip and the matching surface on the inner rim. Made sure all of the original black seal was gone. And then placed a massive blob of sealant between each bolt hole, so much so that some of it came up through the gap and had to be carefully trimmed away. Then I also applied sealant into the gap at the back once the rims were back together.
you dont seal between the lip and wheel, the proper way is to bolt em up dry,and then seal over the join apply one thin bead ...then another thicker one 24 hrs later mine havent leaked in 2 years
Aye, I suppose that way the pressure would be pushing the sealant into the joint, not trying to push it out....
Well, after spending ages with the washing up liquid and water, I actually found the leak! Yeah I kind of agree about not sealing underneath the rim itself. I don't see any harm in doing that as most of the sealant underneath the rim is pushed out when the bolts are torqued. But we thought it would be okay to do both - lightly seal underneath the rim, and also seal the proper way as well i.e. sealing into the gap when you turn the wheel onto its face. Problem is that I obviously didn't seal into the gap on that rim well enough. Fortunately, the other three rims have kept pressure perfectly. There's no leak whatsoever on the front of the wheel. The air is actually coming through the thread on one of the bolts, at the back Bit annoying considering we used thread lock as well.
My mate suggested that I do that, but I was worried that if air is getting past my crappy seal in the first place, it's probably going to find its way past another bolt... hmmm, suppose I could have a go.
This happened to me once when I got a new pair of tyres for an MOT. Took it back and they took the tyre off and checked for any problems - phoned me later to say they couldn't see anything wrong at all. Surprise surprise it stayed inflated after that. They didn't realise they'd fixed it.
the reason you dont seal between the parts is..once the sealer has aged it will shrink a bit then make the bolts loose
In that case I'll re-check the bolts again and ensure that they're still torqued as they should be. I know I am going to sound dumb here but how on earth does one smear one 'small bead' of silicone all the way around the join on an RM? With my RMs, which are standard 15 by 6.5, there's quite a big gap to fill in. I have to use bucketloads of silicone to get even a thin seal...
i dont think your grasping the idea if you tighten em some more...the silicon will still shift about and cause probs my orig bbs rm's were sealed the way im teling you...just put enought on to cover the join, let it set then put on a wider smear...put it this way i had plenty left after doing mine out of one tube of sealer
Mate, I do certainly hear what you are saying. As for the silicone underneath the rim I will just keep a close eye on the wheels and see how they go.
Trev, Are split rim bolts supposed to be torqued to a certain amount when done up?? Edited by: damogti
Yep, 12 to 15nm according to that large Vortex thread. You're only screwing into soft aluminium so don't go mad. With BBS RS rims, you have nuts and bolts, and a higher torque is specified. Also - avoid crossing one of the threads, like I did [:^(]
By the way, to anyone using the Schmidt(sp?) chrome bolts from Germany - I used these and they are lovely, but not to the same quality as the originals. Do check them very carefully and ensure the thread on each one is intact. I was so, so careful not to cross-thread the bolts and yet it did happen. I reckon one of the new bolts had a cruddy thread. Either that, or debris got in the hole from the blasting / powder coating.
Oz bolts also have a nut on the back so they will probably need a higher torque setting aswell then. I dont suppose you have the link to that vortex thread handy do you trev??
Trev, I must warn you that it is really isn't advisable to put together the rims in the way you have. As pigbladder has mentioned(twice), slicone expands and contracts with heat and will get harder over time. You do not want to be driving at 70mph when the tyre decides it fancies letting some air out. When i put together my rims i clean all mating surfaces so they are spotless and dry mount the rims and torque up the bolts to spec. You then seal them up with dunlop sealant. this avoids any movement and ensures you do not allow any air to escape. Have a think. Edited by: CabrioRags
