25 replies to this topic

[gonzoavfc]

~~~~~Please delete this text before posting the topic~~~~~~
Please give your topic a title that quickly describes your problem. Just putting 'Help my Mini doesn't work' is useless to anyone trying to help.
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Model:Mayfair
Year:1992
Description of problem (please be as in depth as possible):

Just started to replace my brake pads, and the pistons are seized up, they aint budging , got me haynes out, and it says about replacing. ive seen repair kits on minispares for the seals and i could buy new pistons and replace them which works out cheaper that new calipers.

I am a poor student and could make my budget stretch to buy new calipers, but is it not too bad a job to put new pistons in?

cheers

[mars red mike]

Putting new pistons in is easy, its getting seized ones out that can be a nightmare.

[gonzoavfc]

well if its easy, i shall do that i would rather have a nightmare than spend more money im a tight arse student lol gotta save for beer money.

Edited by gonzoavfc, 25 June 2009 - 05:21 PM.

[mars red mike]

Just take your time, dont rush and make sure everything is spotless when you put it back together. It is actually quite straight forward.

[il-barba]

on my brother's fiesta he had a non returning piston, after some inspection we found out it was just the hose. the hose was acting as a one way valve

[mars red mike]

on my brother's fiesta he had a non returning piston, after some inspection we found out it was just the hose. the hose was acting as a one way valve

I had something very simialr on a 1996 Escort. It suffered badly with a sticking front caliper. Swapped all manner of parts until I found that someone in the cars past had replaced the brake hose to the caliper and squashed it in the little metal retaining bracket that it sits in. Result was fluid could be forced through the squashed inner pipe but couldnt get back out.

[gonzoavfc]

nah this fecker is rusted up solid, i have disconnected the hose aswell now

[bmcecosse]

nah this fecker is rusted up solid, i have disconnected the hose aswell now

The thread on my grease gun turned out to be 3/8 UNF - and fits the caliper perfectly - so just clamp one piston and pump in grease until the other piston moves. But don't pump it right out! Then clamp that piston and pump grease to move the other piston. Then - pump out the piston which is NOT opposite the hydraulic hole connection - and finally - knock out that piston with a rod through the hydraulic connection - just take care to not damage the thread. Simples !!!! Be sure to clean away ALL the grease - including any in the little passsages - before fitting the new pistons and seals.

[gonzoavfc]

cheers man thats a big help

[Saxo-Fiesta-Mini]

i was shown how to remove the caliper using a block of wood and an airline
some people may not agree with this approach
but never done me wrong when refurbing calipers
just take a bit of paitents and causion
You use a blow gun with the rubber end press it into where the hose goes
then put the wood between the pistons careful not to put ur fingers anywhere near the piston
and slowly press the trigger and build up pressure the trick is to leave them both in and just sticking out
This methods worked a few times for me best with single piston calipers like the old cosworth ones i had on the fiesta but still a good techinique

[kez_19]

i was shown how to remove the caliper using a block of wood and an airline
some people may not agree with this approach
but never done me wrong when refurbing calipers
just take a bit of paitents and causion
You use a blow gun with the rubber end press it into where the hose goes
then put the wood between the pistons careful not to put ur fingers anywhere near the piston
and slowly press the trigger and build up pressure the trick is to leave them both in and just sticking out
This methods worked a few times for me best with single piston calipers like the old cosworth ones i had on the fiesta but still a good techinique

i cant see how an average person with a "normal" garage compressor will be able to build up enough pressure to push out a seized calliper piston and if they did i can see this resulting in damage and injury i would not advise anyone to do this as already stated take your time plenty of WD40 and it will come things like brakes are nothing to "play" around with doing short cuts that may resulting in damage and probably insufficient braking power when needed due to rushing and bodging

michael

[Shifty]

Kez is right, compressed air is dangerous. There is a very real danger of the piston coming out a very high rate of knots.

Something like this should only be considered as a very last resort, there are far better methods, as detailed above

[bmcecosse]

Kez is right, compressed air is dangerous. There is a very real danger of the piston coming out a very high rate of knots.

Something like this should only be considered as a very last resort, there are far better methods, as detailed above

I can't see 100 psi air moving the pistons - it needs good hard pumping with the grease gun! I would say the 'danger' with 100 psi air is very low - but it wouldn't shiuft the caliper pistons I have had to tackle! The grease gun is perfectly safe - and it works - just takes a little time to clean everything up afterwards.

[mini_turbo_pete]

i was shown how to remove the caliper using a block of wood and an airline
some people may not agree with this approach
but never done me wrong when refurbing calipers
just take a bit of paitents and causion
You use a blow gun with the rubber end press it into where the hose goes
then put the wood between the pistons careful not to put ur fingers anywhere near the piston
and slowly press the trigger and build up pressure the trick is to leave them both in and just sticking out
This methods worked a few times for me best with single piston calipers like the old cosworth ones i had on the fiesta but still a good techinique

SFM strikes again.... remember red the bit at the top " Don't give out incorrect advice - if you don't know the answer, don't post!"

For starters you know how to remove a caliper with a block of wood an an airline??? No wonder you had that problem with your caliper falling off your car if thats what you use to take it apart and put it back together, i'm soo glad i don't live anywhere near you!!..

Second.. i've got a blow gun but it hasn't got a rubber end on it...

Third.. when you use an airline to blow the pistons out, one pops out then your stuck because the air can noew escape and there is no way you can leave then just in when it's pumped up with compressed air..

I love the way you have epic fails and make yourself look a complete *melon*.. "best with single piston calipers like the old cosworth ones i had on the fiesta" yeah try and big it up "i had cossie calipers on my old fiesta.." but cossies never had single piston calipers on the front.. EPIC FAIL.. you need to get things right before you can start bullshitting about stuff..

anyway rant over back on topic..

[mini_turbo_pete]

Kez is right, compressed air is dangerous. There is a very real danger of the piston coming out a very high rate of knots.

Something like this should only be considered as a very last resort, there are far better methods, as detailed above

I can't see 100 psi air moving the pistons - it needs good hard pumping with the grease gun! I would say the 'danger' with 100 psi air is very low - but it wouldn't shiuft the caliper pistons I have had to tackle! The grease gun is perfectly safe - and it works - just takes a little time to clean everything up afterwards.

If you have got unseized or partially seized pistons compressed air will move them.

Not all compressors are 100psi, i run mine at 150psi and trust me when the pistons come out they have a lot of force behind them.

I wouldn't only advise people with a lot of exprience to takle getting the pistons out with an air line.