mx5cartalk.com

I recently purchased a MX5, and hope someone can solve my problem.
After washing car or driving in rain (which is rare), I find my back brake/brakes seize when I leave in garage for a couple of days and then when I start to drive out of garage there is a bang and car jumps forward. (frighten hell out of me the first time). After I wash, I find if I drive around the block, to let brakes dry it is OK, but this obviously won't work when raining. Should I take to a brake specialist or is there a simple answer?

Rotors are bare metal so they will corrode quite a lot when directly exposed to water. I'd think the clunk is the brake-pad initially separating from the rotor, the rust causes expansion which puts some additional pressure between the pad and rotor. Then you release the hand-brake and they're still sealed together. It's quite normal unless it's happening when they don't get wet as well.

Personally I live right on the coast so even under a car-cover in the carport there is always a slight rust build-up on them.

this happens on our NC as well, fairly normal for a disc brake rear end, my old fairmont ghia used to do it as well, for the reasons posted above........just try to remember when they ARE wet, or have BEEN wet, to move off gently, puts less stress on the calipers

I leave the car in gear and handbrake off when parking the car in the garage to help avoid the problem.

I find the same thing with my car after I wash it. I do what JBT does and leave the handbrake off after washing (if I remember).

the loud bang is nothing to worry about after washing your car. happens to all cars.
The rear left caliper on the NAs are notorious for seizing. Happened to me and is easily replaced with a second hand caliper. If you find it seems like it is seizing dart your hand under the caliper and try to manually release the handbrake by pulling the rubber casing back.

Thanks fellas for replies, but I don't leave handbrake on only in gear on flat floor. I have a 2004 Corolla and don't have this problem, maybe I have a brake problem not common to MX5's, looks like a trip to a brake specialist.

It's the nature of the beast. It happens to my car each time I had a wash or after driving it in the rain. I make it a habit to go for a very short run in the neighbourhood after a wash and apply the brakes to dry out the rotor. It keeps the rotors shiny and free of unsightly rust. I never have my car in gear or use the handbrake when it's in the garage. Reversing the car will usually free up the pads.

It used to happen to my car with the Mazda pads but not with the Bendix pads I'm using now. It also happens to the front brakes on my bike. It's just normal for the type of pads I think. Though the MX5 was the first vehicle I've owned that has ever done it.

Thanks again for all advise. If problem keeps up after all your suggestions I will try the Bendix Pads. Good to be able to get advise from experienced owners

And remember to pump the brakes after washing and be careful at the first stop. I remember the first time I sailed thru an intersection with no brakes after a wash !

bruce wrote:And remember to pump the brakes after washing and be careful at the first stop. I remember the first time I sailed thru an intersection with no brakes after a wash !

Same here, then I found out you shouldn't wax the brake rotors.

not sure what year your car is but there was a recall on the 2001 - 2002 NB rear brake pads because this was happening alot

Bulletin No: 04-003/02
Last Issued: 9/20/2002

APPLICABLE MODEL(S)/VINS
All 2001-2002 Miatas
DESCRIPTION
After the vehicle has been washed and not moved for a long period, a stick-slip noise may be heard from the
rear brakes once the vehicle is moved. When the vehicle sits for a long period with moisture on the rear brakes,
corrosion appears between the pad and disc plate. The corrosion causes the pad and disc plate to stick
together. The pad and the disc plate separates when the vehicle is moved, resulting in a stick-slip noise.

REPAIR PROCEDURE
1. Review customer complaint.
2. Refer to PART(S) INFORMATION below to determine the correct service brake pad part number.
3. Remove and replace the rear brake pads according to appropriate Workshop Manual (Section 04).
4. Verify repair.

I have a copy of the Service Bulletin if you need one, look on Miata.net I'm sure that's where I got my copy from, they have a very large list on all the bulletins issued for our cars

Move to Melbourne. Car washing's not allowed here.

As per earlier comments though, all the squeakings, grindings, shudders, groans and bangs stopped when I swapped mine to Bendix Ultimates.

Looks like original pads are the problem as suggested. I guess I should have wrote that it was a 2002 model. I will change to Bendix pads, can you advise where I can obtain a set?