Hi guys, a little help & advice would be appreciated.
I had an intermittent sticking caliper (got so hot it burned the paint off the inside of the alloy!). After that it seemed OK though - drove it 30 miles to my garage with no problems, and it didn’t get hot. Garage fitted a new caliper, new brake fluid, test drove, no problem.
Drove home, and a couple of miles from home could hear the same (rear o/s) brake squealing. When I pulled up I checked it out - hot but not absolutely cooking - can’t imagine that it had been binding all the way back or it would have been on fire at motorway speeds!
Anyway, I have had the wheel off, and unlike before it hasn’t freed up - the brake is dragging quite badly. I slackened off the handbrake cable from the adjuster at the handbrake, hoping it was that, but it seems to make no difference.
I want to take it back to the garage to get them to have a look, but obviously I can’t drive it with the caliper stuck.
Assuming that, being a new caliper, it’s not a stuck piston or anything, what can I adjust to a) fix the problem, or b) jury rig it so that I can get the car back to the garage to fix it.
Had a quick phone call to the garage earlier and he reckoned sometimes as they bed in they can bind and need a little adjusting…
Not that much that you can have some toast off them, you are right and something is not right.
It could be the handbrake cable at fault, on that side? See if it is moving free by pulling and releasing the handbrake and see if it is arm on the caliper is moving ok, it could be a faulty caliper? Or just not been fitted correct? or set up right?<o:p></o:p>
Undo the 14mm cap bolt and wind the handbrake off a little more on the caliper see if that helps to be able to get it somewhere that knows these roadsters to sort it out for you.<o:p></o:p>
If you paid the garage to fix the problem, And they have not done so, I wouldnt mess with it. You should call them and get them to collect the car and rectify the problem.
Turn the allen key anticlock 1 turn to slacken off and start again. Then turn it clockwise til the pads just touch the disc. Then turn it anticlock again 1/3 turn.
Check the handbrake cable now has a little slack and the disc can still turn.
Do this with the handbrake lever set to off and the disc clamped firmly to the hub using 2 wheelnuts with washers otherwise it may float around.
Thanks for that - I may give this a go - at least it should make it driveable so I can get it back to the garage. Obv. will have to take it easy when braking in case brake force isn’t equal on the rear brakes.
Do both, once you’ve done one side you’ll find it quick to do the other. It only sets the initial handbrake clearance and won’t affect the footbrake which will set itself when pumped a few times. The continuing adjustment of the handbrake will then be automatic. Test carefully and if the brakes now work and do not overheat there may be no reason to return the car to the garage as that is the way they should have set. If it had been set too tight it cannot slacken itself off other than by wearing the pads. If it is set too loose it should automatically adjust itself with use anyway. The adjuster is there to give an initial setting that works, the ongoing adjustment is automatic.
If, as you say, that adjustment is just for the handbrake then there’s no reason to worry if the footbrake automatically adjusts itself. Should each side be set manually as above and then adjusted at the handbrake lever, or is the latter just for the correct number of clicks on the lever?
Hi, if the cable was adjusted correctly before it should settle out at the same number of clicks after adjustment and use this time.
What you don’t know though is 1) if the cable has been adjusted by the garage after doing the brake job and 2) if the cable is too tight and causing the problem rather than the adjuster on the caliper being too tight
So keeping that in mind, I’d adjust the caliper adjusters both sides as mentioned and set the pistons by pumping the footbrake. Then check that the wheels rotate freely with handbrake off and that the handbrake will lock the wheels when on. If the wheels still won’t rotate check the cable isn’t too tight. Count the clicks, should be 7 - 9 on yours so adjust to this and check lever is putting brake on/off ok at that. Cable adjustment is under the handbrake cover alongside the lever on drivers side. Finally check handbrake light comes on at first click.
You must slacken off the tension at the hand brake lever first, then do as R.M as said and re-adjust back at the lever last for the final adjustments with the 7-9 clicks.<o:p></o:p>
There is a write up on the brake stripdown and rebuild on Mazda-mender.com (link in my sig at the bottom)in maintenance, just waiting for pic’s to be added, which will make it easier to follow, have a read, long, but we tried not to miss anything?<o:p></o:p>
Thanks guys, I have some time on Friday so will get stuck in then. I fiddled with the handbrake adjustment myself (at the lever) to make sure it wasn’t dragging because of that, so it may be out of adjustment now. The near side should be fine as I haven’t touched it and have had no problems with that side. Will reset off side and then check the handbrake adjustment.
M-M - I can’t find the brake guide on your site, any chance of a direct link?
Following all the helpful advice, I slackened off the handbrake adjustment, and removed the 14mm nut on the back of the caliper (not the one for the handbrake lever, the one for the piston adjustment). All the sites (and the Rod Grainger manual) say a 6mm allen key to adjust it. Well I rattled a 6mm allen key around for 10 minutes not being able to get it to fit. Eventually worked out it was a 4mm with help from a mirror (weird, does that mean I have a pattern caliper? Doesn’t bother me, but what else is different…?) but as soon as the head went in, it was clear that whatever was in there was completely loose, and as I withdrew the allen key…
So, not sure where that puts me. Has something on the end of it sheared off? Or is it just loose because it needs tightening or pushing in? Brakes are still binding. New caliper required?
the adjuster gear should just push back in using the end of the allen key. Check it’s engaged and that it winds the piston and if so carry on from where you left off…
Having sussed the piston adjuster, I found that I pretty much have brakes on / lots of drag. It’s really hard to know how much to slack off the screw - people say 1/3 to 1/2 a turn, but there is a lot of drag. I know it’s the diff etc. but there is also a slight metallic scraping sound (same on the other side). Wheel spins about a quarter turn which doesn’t seem right. Quite hard to turn the hub when the wheel is off.
The other confusing thing is now adjusting the handbrake - no idea how much I need to tighten it, help!
The worst thing about this is having nobody to check my work, I know this is all easy stuff but if I put it all together I have no idea if I am going to end up with the hub on fire, or no brakes on that wheel because I have adjusted it too far one way or another…
Don’t worry, you’ll become familiar. There’s quite a lot of drag and some slack as you’re turning the propshaft too. The scraping is the pads brushing the disc. The degree of this is what you don’t know.
Remove the caliper and pads on one side and then turn the hub. You now have a reference for a completely brake-free rear wheel.
Put it back and tighten the allen key til the friction upon turning the hub just increases. Then back it off 1/2 turn.
Pump the footbrake. Go to the handrake lever and set the cable for 9 clicks hard on. By the book this should now be a slackly adjusted handbrake.
Check the footbrake is reset and feels safe and go for a short run. The worse you will find is the handbrake is too slack or too tight. Drive it a little, apply the handrake and footbrake a few times to allow them to auto adjust, get out and check the brake for temperature, if ok try a longer run Finally, if footbrake and handbrake are working ok, go over the cable adjustment at the lever for 7-9 clicks if needed.
M-M - I did read your guide, very helpful it was thank you, it’s just doing these jobs for the first time without anybody to check your work!
Rich - thanks, that is nice and clear. Can I confirm that the footbrake is self-adjusting, so I’m not going to end up with messed up brake bias on one side if I get it wrong (piston adjustment & handbrake adjustment)? Just the handbrake adjustment - so if I err on the side of slackness then I should be OK?
Finally, if footbrake and handbrake are working ok, go over the cable adjustment at the lever for 7-9 clicks if needed.