'07 Mazda5 Brake Master Cylinder options?

Some of the local auto parts list a rebuilt one (~$150), but can't find any available. No rebuild kit available, as far as I can see. And the dealer says none available locally and may be some time before they can have one ($275).

My pedal is sinking to the floor and all else appears to be in order (no leaks, reservoir full).

Anyone go through this recently and can tell me the easiest/best way to get the MC taken care of?

Thanks,
E

I've used auto parts store rebuilds with no problem in the past on several cars. Have you cross-checked the Mazda3 to see if it's the same part? Maybe it's cheaper?

Has this been a gradual issue?


Pad wear and need for brake fluid flushing has significant impact on pedal travel.

I would also suggest looking at changing and properly bleeding the brake fluid first and confirm your pads are not worm down to min specs before jumping to faulty brake MC. Try flcruising's test and report back.

I have bled the system a couple of times over the last couple of years (trying to fix "slow pedal sinking"). Lately, pedal sinks to the floor quickly and brakes are slow to respond... Pumping helps somewhat, but I can tell this is not an "air in the lines" type of issue. Reservoir is still full and we replaced pads about a year ago. Am pretty sure that it's the MC at this point. I am positive that my teen son has put a whoopin' on the brake system and it's easy enough to swap out a MC (in most cases).

Found rebuilt MC online for about $90 shipped and have one now (Cardone 11-3410). EDIT: Verify with the online vendor before placing an order. I purchased a 1st one thru Amazon and order was cancelled, 'cause they did not have in stock (tho said they did online).

What I can't find, is a simple step-by-step to remove the battery box & PCM to access the MC. Anyone have a link to some pics or write-up on how that's done?

Battery box has a front panel that should come off 1st, to pull the battery out, then remove the 3 bolts holding it in the bottom. Finagled the PCM's connectors until they came off.

I still managed to break a tab on the box tho, but was softened from previous work, when changing the battery.

flcruising said:

Has this been a gradual issue?

Simple test.

1. Engine off
2. Pump the brake pedal and hold it when the pressure builds (pedal should get hard)
3. Does pressure build; does pedal hold position?
4. Start engine
5. Notice if the brake pedal travels down slightly.

Report back​

Pad wear and need for brake fluid flushing has significant impact on pedal travel.

Click to expand...

3. Pedal is firm and stays where it should...
5. Pedal "quickly" sinks to floor

I replaced the MC, bled accordingly, and even replaced the front pads (which still had plenty of meat on 'em). Still sinks to floor when braking and brake engagement happens as the pedal is about halfway down. Way back, I barely had to touch the pedal to get brake engagement.

There's a thread on mazdaforum (http://www.mazdaforum.com/forum/mazda5-43/brakes-going-out-please-help-28451/), where a few people have the same issue and have not seemed to find the source of the problem.