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My passenger side rear wheel is getting very hot

Posted: Tue Sep 18, 2007 4:49 pm
by Nycho
Just noticed an interesting problem, My passenger side rear wheel and brake disc are getting waaay to hot. Im thinking bearings, but have not heard that aweful bearing grind at all. the pads look like they have plenty of wear left in them and the disc has no lip. What do you guys think is causing this?

Posted: Tue Sep 18, 2007 4:51 pm
by AJ
pads are binding on the rotor..........probably not fully releasing due to crap in & around the caliper & piston.....or the piston itself has jammed & won't release.....IMO of course 8)

Posted: Tue Sep 18, 2007 4:52 pm
by Boags
Can you be a little more specific about the heat; what is hot? The tyre the rim, the caliper?

How did you notice it?

Is/was your handbrake left on a couple of clicks by accident?

Has it happened more than once?

Posted: Tue Sep 18, 2007 5:21 pm
by Nycho
The hottest part is the disc and caliper(so hot i couldn't touch it), followed by the rim around the centre. the tyre is of normal temp.

I noticed it when was pulled up at traffic lights yesterday and heard a \"clicking\" sound from the back of the car, like metal was cooling down. on closer inspection(at home) i realized what it was. i thought it could have been handbrake too, but i went for a quick drive around the block just before, the same thing happened, deffinatly no handbrake this time. These are the only 2 times it has happened. was ok the day before on a longer trip

Posted: Tue Sep 18, 2007 5:25 pm
by AJ
jack it up on that corner & spin the wheel, if it resists you spinning it, or you can hear anything that sounds like it's rubbing, it's the pads binding on the disc

Posted: Tue Sep 18, 2007 6:34 pm
by JBT
Pad binding can be caused by lack of lubrication on the slider pins. Use brake compatible grease only.

Posted: Tue Sep 18, 2007 6:37 pm
by NMX516
Is it possible on these cars that the handbrake mech on the caliper be seized, or not adjusted properly, and so not release all the way, thereby dragging?

Posted: Tue Sep 18, 2007 6:41 pm
by JBT
Yep, it could be a number of things. Needs to be jacked up and inspected with the wheel off.

Take it to a brake place if you don't have the ability to do it yourself. Brake problems can kill you. :shock:

Posted: Tue Sep 18, 2007 6:50 pm
by clubman1
Hi Nycho,

It's a common problem with the older NA's. The handbrake mechanism is binding up within the caliper. I have done three MX5's now ...all with the same problem. It will very rarely be the slide pins. You need to attend to it ...it will only get worse with time!

Before every time you drive, you need to reach under the rear of the car and make sure the lever arm for the handbrake is fully pushed back. This is after you have released the handbrake (with the car in gear obviously)If you don't ...the caliper drags, ...then can catch fire as wheel as stuff the rear disc rotor in a major way.

The caliper needs an overhaul ...wait for the price of an overhaul kit. :cry: Genuine only ...no PBR's. The last time I checked Mazda wanted about $120 each for an overhaul kit that consisted only of rubbers.

If you are mechanically inclined ...and have a bit of overhaul experience ...you can do it yourself. The whole caliper needs to be disassembled ...there is this awful little pushrod in the rear behind the piston ...with a shitty little circlip down the bottom after the piston is removed. You need to make sure the whole rear end of the caliper is greased well with the high temperature resistant grease ...PBR caliper slide pin grease is what I have found to be best ...don't use rubber or mineral grease.

I get my caliper kits from www.mx5parts.co.uk about 15pds each + postage.

The other option is to find a good secondhand caliper and swap it.

If you aren't mehanically inclined ....don't be surprised by the quote to overhaul two calipers.

Hope this helps

Posted: Tue Sep 18, 2007 8:25 pm
by Boags
Agreed. I think Wuey did a write-up on this recently... :?:

Posted: Tue Sep 18, 2007 8:26 pm
by Boags
\"Wuey\" and \"fire\" in the google search turned this up...

http://www.aus-cartalk.com/viewtopic.php?t=24811&highlight=

:lol:

Posted: Tue Sep 18, 2007 11:13 pm
by sabretooth
I fixed up my rear left caliper last weekend - what had happened was that the part of the caliper that the handbrake pulls on had seized in the \"handbrake on\" position. It wasn't locking the handbrake, but what it was doing was preventing the handbrake from working on the left caliper at all.

I cleaned the whole thing out, ensured that it wasn't binding anymore, and I have a handbrake that operates both wheels again, now.

Posted: Wed Sep 19, 2007 4:08 pm
by Nycho
Awesome! I think you guys are definatly right. the handbrake lever, near the caliper, was a bit sticky and didnt disengage on one of the test drives i went on yesterday. It felt like i had just started towing something, like wuey said. I'll give my rear brakes some TLC 2day and get back to you guys. Awsome help so far, cheers-a-lot!

Posted: Thu Sep 20, 2007 7:11 pm
by Nycho
Yep you guys where right. it was a semi-seized handbrake lever. gave them both a good clean out and lubed them up again. now they move with the handbrake cable :D No more overheating problem

:P :P :P :P