[Mk2] [Generic] Why do mr2 calipers stick?

[Adam86]

Its bloody annoying and dont see why they have this problem? Anyone know what it is about the MK2 calipers that causes this to happen?

[raptor95GTS]

well it's an old car and brakes do get a bit of a pasting. I think all older cars have the same issues, difference is the availability of using other models to acquire replacements. Seem like Toyota used bespoke units for all the mr range

[John145]

2 pins allow the sliding fist caliper to move, these are what stick. I've experienced sticking brakes a lot of cars with a similar age to a mk2 mr2, best way to combat it is greasing these pins up and regularly taking the units apart and putting them together again.

Mind like I've owned a lot of cars atleast 15 years old or older and this mr2 has been the easiest to work on.

[raptor95GTS]

not really idea stripping the brakes every year to fix them especially if you park on the street

[loudandproud205]

I've never experienced it with any other car, and 90% of the cars I've ever owned are late 80's early 90's

[gavinda]

too many people using copper grease for the sliders. it seems to corrode them making them get stuck.

[uglee]

They're just poor design and too many moving parts.

As soon as one of the rubber boots go on the sliders, all manner of crap gets in there and seizes them up. Wouldn't be so bad if the boots were tough durable rubber but they seem unable to stand up to just a few winters without splitting. Seems like they use the same type/supplier for the handbrake cable and piston boots too.

It's not just the sliders that seize, as you've got alloy pistons in a cast iron type piston housing you get dissimilar metal corrosion. This builds up on the outer edge of the piston seal groove and jams the piston solid. You can blow out the pistons and clean up the housing and pistons but it comes back after a few years. I've had MK2's for 10 years and lost count of the amount of seized calipers I've had.

It's interesting to note of all the other old beat up old cars I have owned the last 13 years, none of them have had seized calipers.

[tottacrolla]

Check for rust build up between the rubber slider boot and the caliper.
What happens is that over the years a layer of rust builds up and squeezes the rubber boot harder and harder onto the slider pin.
Biggest issue by far though is the use of non Toyota approved lubricant on the boots. Use ONLY the Toyota caliper grease, anything else seems to swell the rubber causing sticking calipers.

[RST]

To be honest I don't think it's fair that most people only look at their brakes when something's wrong. There are parts in there that are consumables and they should be checked every few years for function and condition. MOT pretty much only checks that they hold minimum values and the discs and pads "look OK" so allot of folk overlook them until there's problems (myself guilty of that).

I haven't experienced massive problems with MR2 brakes. The sliding calliper pins are the same format as on my Aristo. They were the same format as the front callipers on my old MK1 Caddy pick-up also.

I'll give you the handbrake problem though. I'd always argued never to leave a car without the handbrake on if it's parked up before. But if mine's due to be sat for over a week I'll take the handbrake off now so long as it's on the level (I never leave any car out of gear anyway).

You don't need Toyota approved lubricant on the pins -you can get regular calliper grease from most places but agree that copperslip is only a quick fix. It doesn't take that well to heat for a start. Good for bolts but as far as brakes are concerned for me, just good enough for a llight smear on the back of the pads.

I had more problems with my ST205 GT4 brakes to be honest (and they're well known for it) -hand brake was on the rear drums (total nightmare when it seized and the cables pretty much just the same consumables as MR2's) and they have pins spanning both sides of the callipers together on which the pads are "hung" in place. The pins are terrible for seizing in place and they're aluminium callipers so often the only way to fix it is is to hack saw the pins and drill them out. People change them for stainless pins which corrode in place just as good and they're almost impossible to drill out without damaging the ali in the caliper body. I spent 2 days trying to fix my front brakes -then got stuck again on the original problem -corroded brake pistons. The chrome on them goes just the same as any other brake piston I've seen, the rubber boots on pistons is about as think as a condom -not designed to last forever by any means. To be honest, between the Aristo, MR2 and GT4 I've had more problems with seized pistons than anything else Toyota brake wise. Hand brake cables second and seized sliders third.

[uglee]

So Toyota wise you've had a shedload of problems? lol

It's still interesting to note that brakes from other manufacturers seem to be generally longer lasting and Toyota units from the 90's are very high maintenance to keep in tip top condition. I've claened up units myself, I've bought refurbed and all last maybe 2 years. In 10 years it must have been 7/8 caliper changes, 4/5 handbrake cables and 5/6 pins/carrier changes.

They're just xxxx lol

[StevenstonWullie]

Out today for a drive and thats my offside rear sticking thats the 2 fronts and looks like the rear have went alll in a year i keep my brakes clean always dry them well off after washing.... it was the lower piston twice on the fronts that stuck il bet it the piston on the rear they are too exposed.. bad design ....i drive a wee fiesta 1.3 as my daily drive i live on the coast it can sit fotr 2 wks at a time wind and rain never had any probs with brakes with it ... my tubby is kept in a dry brick lock-up and very rarely sees rain, im actually a wee bit p'd off

[Zeppozen]

Glad someone is admitting the truth that these cars brakes are utter pants.

I barely use them (other cars I have road rallied on standard brakes with no problems) and they still perform poorly or seize.

Leave the car standing for 2 days in the rain and I'll be lucky if the car will move due to seizing.
have renewed Calipers time after time but these are still xxxx.

I wouldnt mind if I hammered the brakes but these Toyaota Design Calipers are positively ARTHRITIC !!

Rear has just gone again ( after getting the fronts fixed).

Be nice to be able to drive these cars for more than a week in British weather without having to strip it down to clean and re grease.

If your thinking of buying an MR2MK2 be prepared to get your hands dirty on a regular basis and your mind scrambled at why ?

[uglee]

Well after 10 years of the damn thing seizing I've had enough and these are going on the car once I've got them all like the silver one.

[raptor95GTS]

phoawr, you kept that quiet! When did these puppies turn up, been looking for calipers for you but obv not well enough!

[uglee]

Got them on the Bay of E's a month or so ago matey. The fronts were in pretty good nick if they had put some blanks in to stop the old brake fluid peeling off the laquer. So thought sod it I'll go to town with them. The rears are cosmetically ratty but are fine underneath.

Downside is it took me 4 hours to do the one caliper and the others are in a worse state. However it does look pretty good in silver.

I'm going to get some brackets made up for the 911 rear calipers soon that will incorporate a mechanical spot to work with the RX8 discs. Want me to get an extra set made?

[raptor95GTS]

ooo tempting, go on, you know I want a full set lol How you sorting the handbrake out?

[uglee]

Was thinking of using a mechanical spot caliper bit like this, but unsure about its holding ability to be honest.

http://www.ebay.co.uk/itm/Mechanical-Ha ... 1c17352db6

If it looks like they won't hold I'll go full hydraulic with hydraulic handbrake and stick on a nice clean shiny pair of standard calipers come MOT time. Anything to ditch the calipers for 364 days a year

[uglee]

Another option is a left and right hand side pair of these:
http://cgi.ebay.nl/ASTON-MARTIN-V8-VANT ... 336a69bace

I like these too, much better engineered than the cheap ebay ones.

http://www.ipsco.org/Custom%20Services/ ... 0Brake.htm

[Ryan S]

had my mr2 4 years and never had the calipers stick once

[raptor95GTS]

had my mr2 4 years and never had the calipers stick once

give it time