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Discussion Starter · #1 ·
Hi, did the discs and pads on my mk1 this weekend and had a couple of snags. The fronts weren't too bad but the greenstuff pads appeared too "fat" to allow the caliper to sit back over them with a new disc on. Piston pushed back in fully no problem, ended up taking the stick on backing tap off the pads and not re-using the metal backing plates from the old pads. If this is an issue, I can wear them down a little and add the metal plates later - will this be ok? Funnily enough I had this issue with greenstuff pads 20 years ago on a previous 5.....

Rears, I had the backing plates fall apart in my hands when I took them off - think they'd been on the car from new. drivers side was fine but no "W" spring. Passenger adjuster didn't move the piston and when it came out with the allen key, was all chewed up. Also no W spring on that side either. I had to gently push the piston in a little to get the disc and pads on, but couldn't adjust it back up. Ordered some W springs and a new adjuster.

So, is it ok to run with no backing plates? Are the W springs just to stop any rattles? Anyone had similar with the adjuster and should it work ok or likely a seized piston? Assume that means new caliper?

Thanks
 

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Early Man
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So, is it ok to run with no backing plates? Are the W springs just to stop any rattles? Anyone had similar with the adjuster and should it work ok or likely a seized piston? Assume that means new caliper?
Yes - backing plates are not necessary but can help reduce likelihood of brake squeal.
Yes - w springs are not necessary but can help to push the pads off the disc & reduce likelihood of brake squeal.
I suspect the reason the adjuster is chewed up is because the piston is/was stuck (did the disc look like the brake had been working effectively?) If it is stuck, a replacement caliper is usually the easiest way to deal with it.
 

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Banish a little rust a day people
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Rears are likely seized, it's ll be rust in the piston bore and on the piston itself, which also means all the sealing surface will be rusty. You'll need new or to rebuild. Adjuster is chewed up for this reason, no point adding a new one until the cause is addressed.

They arent needed but pads should fit with the backing plates, if not it's likely you have rust preventing the piston retracting all the way, it should fully retract and sit flush with the caliper.

W springs arent needed either, they help reduce pad drag and squeal but the SVT sports brakes and loads of aftermarket ones dont even come with them.
 

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Hi, did the discs and pads on my mk1 this weekend and had a couple of snags. The fronts weren't too bad but the greenstuff pads appeared too "fat" to allow the caliper to sit back over them with a new disc on. Piston pushed back in fully no problem, ended up taking the stick on backing tap off the pads and not re-using the metal backing plates from the old pads. If this is an issue, I can wear them down a little and add the metal plates later - will this be ok? Funnily enough I had this issue with greenstuff pads 20 years ago on a previous 5.....

Rears, I had the backing plates fall apart in my hands when I took them off - think they'd been on the car from new. drivers side was fine but no "W" spring. Passenger adjuster didn't move the piston and when it came out with the allen key, was all chewed up. Also no W spring on that side either. I had to gently push the piston in a little to get the disc and pads on, but couldn't adjust it back up. Ordered some W springs and a new adjuster.

So, is it ok to run with no backing plates? Are the W springs just to stop any rattles? Anyone had similar with the adjuster and should it work ok or likely a seized piston? Assume that means new caliper?

Thanks
Hi there, can you provide for me the part numbers for the Greenstuff that were too thick? What year is your Mk1, and is it 1.6 or 1.8L engine? There are two pad shapes differing depending on which model, so first I would like to ensure you have the correct part. According to my chart the thickness of the pad should be 14mm regardless of which fitment.
The pads will work without plates and spring, but it is recommended to have these for best use.
 

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Discussion Starter · #5 ·
Hi, thanks for all the responses, I think I need at least one rear caliper, might do both. Can anyone recommend a supplier other than main dealer?
Front pads are marked DP21002 on the box, car is a 1995 1.8. I didn't keep the box for the rears, only kept the fronts as I'm hanging onto the backing plates to put on when the pads wear down if they're noisy. I should have checked numbers but basically just bought discs and pads from Larkspeed via ebay. I must add the discs are not ebc, not saying the pads are to blame. I've run many sets of Greenstuff on MX5's for nearly 25 years - only had this issue once previously with a set in 2004. Again not ebc discs then either so no idea what the issue was. Piston is fully in, sitting flush. Thanks
 

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Hi, thanks for all the responses, I think I need at least one rear caliper, might do both. Can anyone recommend a supplier other than main dealer?
Front pads are marked DP21002 on the box, car is a 1995 1.8. I didn't keep the box for the rears, only kept the fronts as I'm hanging onto the backing plates to put on when the pads wear down if they're noisy. I should have checked numbers but basically just bought discs and pads from Larkspeed via ebay. I must add the discs are not ebc, not saying the pads are to blame. I've run many sets of Greenstuff on MX5's for nearly 25 years - only had this issue once previously with a set in 2004. Again not ebc discs then either so no idea what the issue was. Piston is fully in, sitting flush. Thanks
I go to my local scrappy (mx5partswarehouse) and get a used calliper. £20 and some brake fluid easy job. Im sure rebuilding the callipers would be better but seemed like more work than getting a known working one
 

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Happily expanding the To Do list since 1997
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Having replaced a few rear calipers over the years due to this problem (piston seal perishes and lets water in, piston rusts and won't retract, retractor screw gets chewed up while trying) I bought a pair of replacement calipers, probably from Autolink, but kept the old ones so I could refurb those for next time, so I would have known good ones to fit if the pair on the car had problems. Might have been a bit of overkill but it was insurance against getting stuck when it was my only car.
 

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Discussion Starter · #9 ·
Thanks all, 1 last try this weekend (autolink new adjuster and W springs just arrived) then I'll bite the bullet and replace the caliper. Going to try to free up the piston with some plus gas and move it in and out slightly to break the hold the rust has on it.

Cheers
 

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Hi, thanks for all the responses, I think I need at least one rear caliper, might do both. Can anyone recommend a supplier other than main dealer?
Front pads are marked DP21002 on the box, car is a 1995 1.8. I didn't keep the box for the rears, only kept the fronts as I'm hanging onto the backing plates to put on when the pads wear down if they're noisy. I should have checked numbers but basically just bought discs and pads from Larkspeed via ebay. I must add the discs are not ebc, not saying the pads are to blame. I've run many sets of Greenstuff on MX5's for nearly 25 years - only had this issue once previously with a set in 2004. Again not ebc discs then either so no idea what the issue was. Piston is fully in, sitting flush. Thanks
The part numbers look to be correct, so the part should fit inclusive of shims etc. My only thought is that the caliper pistons were not quite fully in, or that the rotors are too thick/ the wrong part. Sorry to not have a more precise diagnostic for the issues.

You can safely use them without shims and spring so if you are not having any noise and are happy to do so, you can continue without issues.
 

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Discussion Starter · #11 ·
Thanks for coming back. Front piston is fully in, may be disc thickness, generic part from Larkspeed. I have springs on the fronts, just none on the rear but have a set to add this weekend. No issue with fitment on rears btw. Cheers
 

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Just to add my Greenstuff experience I have also just taken the backing pads off to make them fit on three different Eunos 1.8s
All instances cars were fitted with new discs at the same time.
No problem with brake squeal.
 

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I have spoken with the manufacturing team and will be making efforts to ensure the brake-in coating is not applied too thick so fitment is easy to drop in. The black backing plate that is stuck on the EBC pads ensures that any additional shims/ plates are not necessary, this black shim is all that is needed.
Our machining makes all pads to the exact measurement but the brake-in coating may add thickness, so we are going to refine to ensure the finished product is of exact measurement.

If the pad is too thick due to the brake-in coating (if you already have a set and find this issue) you can file/ sand, by hand, the surface to reduce thickness. Do not go far past the brake-in coating as the pad face itself should be as machined.
 

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Early Man
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To listen to feedback and act in such a positive way is a hell of a good response btw. Most companies just keep churning out the same stuff which doesn't quite fit or doesn't quite line up or simply isn't perfect in some other way.

Refreshing to see someone who actually embraces an opportunity to tweak a product for the better. Well done!
 

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To listen to feedback and act in such a positive way is a hell of a good response btw. Most companies just keep churning out the same stuff which doesn't quite fit or doesn't quite line up or simply isn't perfect in some other way.

Refreshing to see someone who actually embraces an opportunity to tweak a product for the better. Well done!
Thank you, we see all feedback, negative or positive, as a chance to improve and better understand the market and customers views. We are invested in producing the best products we can, and take every opportunity to learn :)
 
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