AX braking problems and waxoyl question

vanny · Unread post by **vanny** » 19 Jul 2005, 03:58

when braking (bit it hard or soft) the AX tends to snake all over the place. Im not very ofey with 'normal' brakes but is this likely to be down to air in the brake lines?
at the service last year (i was out of the country) the front O/S caliper was replaced. I though ti was standard practise to replace pads and discs at the same time but this wasn't done! The front N/S squeaks a lot and lightly pressing the brake will stop the noise until the brake is released, its also very interemittent. I did copper slip the hell out of all moving bits around the brakes (pack of the bads, carriers, sliders etc (no not the discs [:D])), but it never really vanished just went away a litle. Could this be warped/old discs? the discs i think ar original from buying the car in 1995 and 70k miles any thoughts on resolving the problems?
I want to do some preventative maintenance on the car to keep it going forever, and im thinking id like to waxoil the hell out of it. Any suggestions on how to apply, and where to apply? i do have a air line and various sprayers if it helps?

oscarloco · Unread post by **oscarloco** » 19 Jul 2005, 05:50

You should check the discs. If they aren't flat, the lip that forms in the center and in the outside makes a lot of noise. I had a similar problem, if I braked lightly they would squeal like crazy. If I braked harder, no noise. So I replaced both discs.

caveman_si · Unread post by **caveman_si** » 19 Jul 2005, 07:45

vanny next time you seem me mention waxoyl i know you can apply it with a line but u need to put it in a solvent i think. cant remeber what solvant but im sure its something you have lying round the house. ive me a day to wrack my brain and i'll get back to you its my 1st day back at work and my brains not working.

jeremy · Unread post by **jeremy** » 19 Jul 2005, 11:53

Solvent for Waxoyl is white spirit as obtained from your friendly B&Q
Vanny - I don't think the discs are warped as this would produce a vibration when the brakes were applied. I think your discs have high spots caused by aear and rust, and think that if you take a pad out you will find that there is at the edge a small part that is sitting on a high spot. I had this on the ZX and couldn't explain why the brakes never seemed to bed in as the discs themselves weren't that bad. In fact some pads are different shapes and I see no reason why you can't remove the bit thats in the way (probably inside edge.) Bevelling the leading edge may help as well.
I found an advert for green stuff and red stuff pads last night and I see that they have an abrasive coating on top and that both leading and trailing edges are well bevelled. This is an old trick used to make drum brakes work sweetly and I'v always found that taking just a touch off with something like a wood chisel produces results. Incidentally I don't think I have ever greased the back of a pad yet.
Jeremy

cornishbx16v · Unread post by **cornishbx16v** » 19 Jul 2005, 15:40

Hey Vanny! Waxoil needs 15-20% white spirit mixed with it to allow it so bond to the bottom of the car! its really worth jet washing of the bottom of the car first to get rid of all the gunk on there and to give the waxoil a good chance of bonding! (i used to do it every week at work!) we used to apply it with an air gun, although the particles get every where! used to go in looking like darth vader but it helps! if you dont want to spray it on you can 'paint' it on with the usual brushes etc but it will take considerably longer! but you ,may get a thicker coat! as an alternative, i used Tetraseal on mine, only cost £8 from the wholesalers! just heat it up a bit to make it easier to apply and your away!

vanny · Unread post by **vanny** » 20 Jul 2005, 02:48

Thanks Guys!
Took the offending wheel back off today to find the problem was as suspected, the wear on the disc was catching the pads! However the pads and discs are apparently original to the car (i personally dont believe after 70k miles them can still have some 13mm of depth on the pads, BUT the fricfriction material on the pads is coming away from the metal backing! Figured sod it i'll replace pads and discs! Took the local supplier a while to figure out the pads (4 options for the AX fronts and two for the back! Eventually i just pointed at one and it turns out it was right!) however the discs are much too small! Didnt notice till i got them on the car and couldnt figure out why the pads over lapped the edge! SO went back to the drawing board and as suggested 'trimmed the pads with a wood chisel (hell it was handy) and cleaned as much corrosion of the old disc without without scratching the braking surface. Squeek has stopped and would you believe it, the brakes are now pulling up straight!
Going back to swap the discs and fit the new pads/discs tomorrow!
On the rust front, only really the back suspension components are a problem where paint has flecked off so i guess i dont need perhaps as much waxoil as i thought!

Unread post by **Peter.N.** » 20 Jul 2005, 03:18

If you are filling cavities with waxoil it's good to spray some ordinary engine oil in first as Waxoil tends to set without creeping into the welded joints, better if you do it in really hot weather. For underbody sealing it is better to use a dedicated sealer as has been suggested as Waxoil tends to get abraded by stones and gravel.

citronut · Unread post by **citronut** » 20 Jul 2005, 04:00

when fitting new pads to oldder discs i allways buff the inner and outer edges gently with grinderet,not leading edges,it helps to let the pads sit flat if there are any lips on discs regards malcolm

Unread post by **martyhopkirk** » 20 Jul 2005, 13:07

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by vanny

when braking (bit it hard or soft) the AX tends to snake all over the place.<hr height="1" noshade id="quote"></blockquote id="quote">
Mine does this - replaced the pads, shoes bled it and it still does it. Come to the conclusion its a bag of carp.
<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by vanny
I want to do some preventative maintenance on the car to keep it going forever,<hr height="1" noshade id="quote"></blockquote id="quote">
WHY?[:o)][:o)][:o)]

jeremy · Unread post by **jeremy** » 20 Jul 2005, 13:46

The reason I'd use a chisel and cut the pad rather than grind is is simply for my own health. I know they don't use asbestos in new pads now but I'm sure the dust doesn't improve your health.
Jeremy

vanny · Unread post by **vanny** » 20 Jul 2005, 16:03

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by martyhopkirk

<blockquote id="quote">quote:<hr height="1" noshade id="quote">
[quote]Originally posted by vanny
I want to do some preventative maintenance on the car to keep it going forever,<hr height="1" noshade id="quote"></blockquote id="quote">
WHY?[:o)][:o)][:o)]
<hr height="1" noshade id="quote"></blockquote id="quote">
Dunno, ask my mum, but so long as she is happy with it then i dont have to find her a mini (cooper in racing green is what she wants, but it seems like a horrible way for a car to go!)