Guide: How to Flush brake system Mazda CX-5 DIY

[felixd]

Hello guys just another DIY write up , I would like to share of what I did over the weekend .

Job : Flush Brake fluid system
Method : One man method
Vehicle : Mazda CX 5
Year : 2013
Odometer : 20000kms
Fluid : Castrol DOT 4

Tools & Equipment that i have used to perform this job are Standard Jack & ( Jack stand i did not have these laying around ) But if you do have it please use it for safety, Breaker bar with 21mm socket , 10mm ratchet spanner (I did not bring my spanner this time so i replaced it with 3/4 ratchet with 10mm socket & Adjustable spanner), Suction tool / equivalent , fluid catcher bottle and old clean rag.



Warning : Do this at your own risk and i will not be responsible for any damage caused by following this steps. I have done this job numerous times before hand to get somewhat a perfect result , so if you are not competent please leave it to the professional. Failure to do this DIY may cause injuries & fatal accidents on the road.

So the sequence i have used of doing the proper Flushing brake fluid system are starting the job at the furthest side from the brake master cylinder & then work your way up to complete.

My case i started at passenger rear side , following by driver side rear , passenger side front and lastly driver side front .

Prior doing the job , please make sure the vehicle is Cooled down , Put the car in P mode with hand brake down , Open the vehicle bonnet , Place the rag below the Brake fluid reservoir, Locate and open brake fluid reservoir cap and using suction tool / equivalent to extract some old brake fluid out from the reservoir and placed it in the brake fluid catcher bottle like shown below. Remember to fill the brake fluid back in the reservoir with fresh brake fluid till at the full mark .











Step 1 : Start from Passenger side rear . Remove wheel. Using the breaker bar with 21mm socket, Jack up the vehicle , Put jack stand. While at it i decide to give a clean scrub on the calipers.









Step 2 : Using 10mm spanner to crack loose the nipple of the brake caliper, attach the fluid catcher bottle tool to the nipple , in the car push the brake pedal 5 times or more . Refill up the brake fluid in the bottle reservoir. Repeat this step until you can see Clean brake fluid from the fluid catcher tubing and make sure there are no more air bubbles before tightening back the nipple. Re install the Passenger side rear wheel assembly.









Check the brake fluid reservoir & refill . Mine was like this . See the particle and dirt that needed to be flushed out .



Step 3 : Working on Driver side rear . Remove wheel . Using 10mm spanner to crack loose the nipple of the brake caliper, attach the fluid catcher bottle tool to the nipple , in the car push the brake pedal 5 times or more . Refill up the brake fluid in the bottle reservoir. Repeat this step until you can see fresh brake fluid from the brake fluid catcher tubing and make sure there are no more air bubbles before tightening back the nipple. Re install Driver side rear wheel.









Example below are the bubbles you have to get out off the brake system.





Step 4 : Working on Passenger side front . Remove wheel . Using 10mm spanner to crack loose the nipple of the brake caliper, attach the fluid catcher bottle tool to the nipple , in the car push the brake pedal 5 times or more . Refill up the brake fluid in the bottle reservoir. Repeat this step until you can see fresh brake fluid from the brake fluid catcher tubing and make sure there are no more air bubbles before tightening back the nipple. Re install Passenger side front wheel.













Step 5 : Working on Driver side front . Remove wheel . Using 10mm spanner to crack loose the nipple of the brake caliper, attach the fluid catcher bottle tool to the nipple , in the car push the brake pedal 5 times or more . Refill up the brake fluid in the bottle reservoir. Repeat this step until you can see fresh brake fluid from the brake fluid catcher tubing and make sure there are no more air bubbles before tightening back the nipple. Re install Driver side front wheel.











Step 6 : In the engine bay clean the brake fluid reservoir and fill it up till the full mark and close the filler cap. Press pedal couple more times . Start the vehicle make sure no ABS warning light are on in the dash .







Conclusion If the job were performed right and in the correct manner the brake pedal and braking power should feel more responsive. Here are the result from 20000kms of 3 years ownership under normal driving condition. The old brake fluid were so bad in color , there's a lot of dirt particle in it as shown below .







Please correct me if i am missing steps or whatsoever. Peace out.

 

[tibimakai]

Nice job.
The end of the tube, has to be submersed in fluid at all times, right?

 

[Silv3rCX5]

Thanks for sharing. There are so many ways to do this, first time I've seen it done this way. Seems less of a hassle than the traditional way with two people with pumping and holding.

 

[felixd]

Nice job.
The end of the tube, has to be submersed in fluid at all times, right?

That is correct. Thus preventing air to be sucked back into the brake system.

 

[ijaen]

Opening the nipple at the caliper and then pushing the brake is not the best way to do this, you are allowing air to enter the system. You should have someone push the brake and then open the nipple. The fluid was very dirty for only 20k kms (14k miles or so)! (boom01)

 

[erhayes]

Thank you so much for this great instructional tool. Ed

 

[felixd]

Opening the nipple at the caliper and then pushing the brake is not the best way to do this, you are allowing air to enter the system. You should have someone push the brake and then open the nipple. The fluid was very dirty for only 20k kms (14k miles or so)! (boom01)

Yes the other way of doing this is by 2 person job but in my case had only 1 person . If there's a bubble left over in the system you will be able to see it before tightening back the nipple thus you will have to repeat the process until it is clear before tightening the nipple.

 

[CX-5um]

Good effort felixd!! Good resource for the DIYers although I think I'm going to hire a mechanic on this project. Just waiting for my brakes pads to wear out so I can get everything done at once. I'll definitely buy DOT 4 fluid though.

Any improvement in braking feel/distance?

 

[Silv3rCX5]

Yes the other way of doing this is by 2 person job but in my case had only 1 person . If there's a bubble left over in the system you will be able to see it before tightening back the nipple thus you will have to repeat the process until it is clear before tightening the nipple.

Sometimes air can be drawn in through the threads of the nipples if its loosened too much and you might not see it.

 

[tibimakai]

I have already purchased one of these, but I have not used it yet. But I will do it next time, when I work on my brakes.

 

[Tom 6-6]

Please let us know how the suction method works. A how -to would be great.

 

[felixd]

Good effort felixd!! Good resource for the DIYers although I think I'm going to hire a mechanic on this project. Just waiting for my brakes pads to wear out so I can get everything done at once. I'll definitely buy DOT 4 fluid though.

Any improvement in braking feel/distance?

Yes definitely there are improvement in braking feel and stop distance. Prior this service usually i had to give approx 1.5 inches brake pedal pushed before the vehicle response to the brakes. After doing this maintenance i literally give approx less than 1 inch brake pedal push before the vehicle response to the brakes.

 

[CX-5um]

Yes definitely there are improvement in braking feel and stop distance. Prior this service usually i had to give approx 1.5 inches brake pedal pushed before the vehicle response to the brakes. After doing this maintenance i literally give approx less than 1 inch brake pedal push before the vehicle response to the brakes.

Good thing about DOT 4 is it provides higher heat/humidity protection.

 

[madar]

I always used a 2 by 4 and jammed it between the brake pedal and the drivers seat and then went down to crack open the nipples to relieve the pressure, tightened the nipple and then pumped the pedal. Do it for all four wheels until the clear stuff comes out. Of course, you could always just open a nipple, pop off the cover of the master cylinder and let gravity do its job, a bit slower but it works as well. Just don't don't pump the brake pedal and make sure the master cylinder is always full.
Also noticing the dirt particles in the master cylinder, probably would've sucked the fluid out of there to get the dirt so as not to draw it through the ABS unit. ABS units typically don't handle dirt well, some have thrown a code because of it. Good pics, though.

 

[Triton46]

Where can I purchase a replacement the blue filter? I had a shop perform a fluid flush about 2 years ago...its gone.

 

[yrwei52]

Where can I purchase a replacement the blue filter? I had a shop perform a fluid flush about 2 years ago...its gone.

The best place to find that blue filter is at Mazda dealer. But I suspect you have to get the whole brake fluid reservoir which includes the filter. You may try salvage yard but again you may have to get the whole brake fluid reservoir and master cylinder.

 

[timberstx]

How do you get that blue filter out of the reservoir? I've bled my brakes 3 times so far. But I can never get that filter out to remove the old fluid first. On past cars I could just lift it out. This one is in the reservoir and is snapped in on the four corners. I tried a sponge but just could only get one up at a time.

 

[ruthrj]

I gently pulled mine out with needle nose pliers.

 

[raj55]

Opening the nipple at the caliper and then pushing the brake is not the best way to do this, you are allowing air to enter the system. You should have someone push the brake and then open the nipple. (boom01)

Not entirely true for two reasons.
1. The placement of the end of the tubing under the level of old brake fluid in the bottle does not allow the air to be sucked in and
2. secondly, there is a pressure difference (height difference) between the car's brake fluid reservoir and the wheel nipple so the tendency of the brake fluid is to flow down towards to the nipple, very slowly by gravity.
The only thing that I would do differently is to attach the end of the plastic pipe to the nipple before cracking the nipple itself open so that there is absolutely no chance of air getting in (even if you did not have gravity to help you). I have a triple safe method and that is the tube that is immersed in the plastic bottle has also a one way valve attached to it and it is under the brake fluid level (and of course the gravity is on your side too). What I have noticed in practice is that the moment you crack open the nipple, the brake fluid starts flowing down that pipe slowly. You could literally do gravity assisted brake fluid change without pumping the pedals but it would take a long time. Just my two cents.

One more thing, after bleeding the fluid, spray some WD 40 around the nipple before tightening it so that there is no rust, next time you go to open that nipple. Don't tighten it too hard or you will break it!

 

[raj55]

I have already purchased one of these, but I have not used it yet. But I will do it next time, when I work on my brakes.

In theory this suction method makes most sense and is the safest but in practice there is often air leak around the plastic tubing attached to the nipple and that appears as bubbles in the plastic draining tube causing a lot of confusion. Is it air bubbles in the brake system or is it just the air being sucked in due to bad seal between the plastic tube and the nipple? One way of minimising that would be to apply low suction so that outside air does not get sucked in at the nipple tip.