Master cylinder problems

mg_0401

Member
:
mazda 5
Hi guys, I hope someone can help me with this issue. I few days ago my brakes went all the way to the floor. I have checked all the pads , checked for leaks, and even checked for any cracked brake hoses and everything looks fine. I even tried bleeding the brake lines but no luck. I also hear a pew noise everytime press and let go of the brakes. I have read all threads on this and seems to be the master cylinder. Can someone confirm this and if it is do I have to bench bleed the new MC? Thanks for your input on this issue.
 
It looks like you've taken all of the usual troubleshooting steps...The MC is the likely culprit. Did you check for leaks at the caliper piston seals (that would be obvious), the seals between the MC and the reservoir (any stains near that area?), the hose from the reservoir, leaks from the lines on the ABS controller/proportioning valve (rare), and the ultra-rare-if-this-is-your-problem-buy-a-lotto-ticket hard lines that run the length of the van.

And yes, bench bleed the MC to get rid of most, if not all, of the air. Not doing it will extend the time to bleed the braking system. Let us know how it goes.
 
It looks like you've taken all of the usual troubleshooting steps...The MC is the likely culprit. Did you check for leaks at the caliper piston seals (that would be obvious), the seals between the MC and the reservoir (any stains near that area?), the hose from the reservoir, leaks from the lines on the ABS controller/proportioning valve (rare), and the ultra-rare-if-this-is-your-problem-buy-a-lotto-ticket hard lines that run the length of the van.

And yes, bench bleed the MC to get rid of most, if not all, of the air. Not doing it will extend the time to bleed the braking system. Let us know how it goes.

Thanks MR6 for the reply, I have checked everywhere for any type of leaks and yes even between the MC and the reservoir and everything is dry. I guess I will change the MC this weekend and let you guys know how it went.
I have another question? Kind of a dumb question but i will ask it anyways, How do bleed the MC cause it appears to be closed and only a small hose that comes from he resorvoir is the opening for it.
 
Good luck. My master cylinder went bad and I rear ended a car at a stop light. Cost me $560 for a replacement at the stealership, have fun.
 
I have another question? Kind of a dumb question but i will ask it anyways, How do bleed the MC cause it appears to be closed and only a small hose that comes from he resorvoir is the opening for it.
You have to bench bleed it. Youtube has some nice tutorials.


Good luck. My master cylinder went bad and I rear ended a car at a stop light. Cost me $560 for a replacement at the stealership, have fun.
Sucks to hear about the accident. $560 is insane for a master cylinder, unless this includes installation (still pricy). They are not very complicated contraptions. Rockauto has remans units for $60-$100 (no core charge either). Also, I don't see any rebuikd kits, which is strange considering the number of Mz3 on the road...
 
Onlinemazdaparts.com has them for a bit over 200. I wouldnt buy reman and i reserve rock auto parts only for non-critical s***. A critical part like an MC should be oem imho. The worst part of the install will be getting the van up on all fours and bleeding. The MC install itself should be fairly easy as long as its not buried up against the firewall.
 
Sucks to hear about the accident. $560 is insane for a master cylinder, unless this includes installation (still pricy). They are not very complicated contraptions. Rockauto has remans units for $60-$100 (no core charge either). Also, I don't see any rebuikd kits, which is strange considering the number of Mz3 on the road...

I would've attempted it myself but I needed it done by a certified Mazda tech to show that it was faulty equipment (for the citation I got). Plus apart from changing brakes and rotors I'm none to keen on messing with the braking system.
 
I take it back. i was just looking at my MC...it's buried behind the battery box and all of the fuse blocks. Ur gonna have to pull the battery box at the very least. Odd placement as the brake booster is usually mechanically connected to the brake pedal. Good luck!
 
i got one off a 2010 mazda 5 it looks great and clean. let see if it works. it only cost me $20.00.
 
replaced the master cylinder over the weekend and bleed the brakes and everything works great. just like before. You can't beat an orginal MC from a donor 2010 Mazda5 from ebay for $20.00..
I'll keep everyone posted on the repair of the MC. thanks
 
So satisfying when the OP comes back to a thread to confirm what the solution was - I hate searching for some random issue I'm having and just finding a bunch of unresolved threads.
 
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