Brake Master Cylinder and Brake Fluid
 

Hello everyone,

Today I received my car after installing some parts including a brake SS lines and changing fluid from OEM to Motul rbf600. Everything seems alright. The issue here is my mechanic recommended me against changing OEM Dot 3 to Dot 4 and made me sign on taking the responsibility myself if anything went wrong with the brake system :confused:.

The reason he gave me is

"The brake master cylinder of the Z is designed for Dot 3 fluid types and it shouldn't be used with any other than that type, as the materials of the bmc is not compatible and it might cause fire in the system :confused:"

I am not an expert in these things but I just cannot understand his point (which made me insisting to go forward with the motul) and at the same time I cannot overlook what he said. Maybe he is mis-informed about it, maybe the difference of climate is one point to consider (as here in Qatar it can reach 50 Celsius and it is very humid in summer). So I just want to make sure of this point.

Also, how often to change the fluids? As I read here, every 6 months seems right. Maybe I should go for every 4 months as the weather here is very humid at times?


Sent from my SM-T325 using Tapatalk

Your mechanic is very mis-informed! Brake fluid will not catch fire. It will smoke alot when poured on to a fire. :D The o-rings in the system will not be harmed with the Dot4 fluid. How many guys here who have changed brake fluid here with no problems. Alot! If you just use the Z as a DD, and don't track it. Just bleed the brakes once a year, and you will be fine. ;)

Thanks a lot Rusty, he didn't make sense but at least he can install the parts.

The car will see the track occasionally, like 5-7 times a year. But no serious racing, just having fun and trying its limit.

Sent from my SM-G920F using Tapatalk

if you're going to be tracking it 5-7x a year, i would change the fluid every 3 track days. that's my experience at least. pedal starts to go mushy by the 3rd day with average humidity here in california. not sure how the weather is in qatar though!

Thanks a lot chops, I think I will stock some new fluids in my garage.
And the humidity is around 50% to over 75% here in Qatar now. Some time more.


Sent from my iPhone using Tapatalk

I bleed my brakes every 3rd trackday. Unless I feel the need to do it sooner. Of course I'm running brake cooling ducts too with Racing Brake 2 piece brake rotors, and Ti heat shields between the pads and brake pistons.

I can't believe he thinks it'll catch fire hahaha wow! But I think he's thinking of mixing dot 3 OR 4 with silicone dot 5. Those cannot be mixed.

Exactly, but the fire part is LOL. The silicone stuff will damage the system/ not work properly, but it still wont catch fire.

And you still let him work on your car? I just wonder what other things he's misinformed about or incompetent to work on :eekdance: I would stay away :twocents:

I bought a power bleeder for $70 and do my brakes once a year (DD with no track/autox). Also, I've got over 50K miles with Dot 4 fluids (mostly RBF600). No issues.

Thanks guys, it is a problem here in Qatar, we don't have good and true mechanics, let me put it that way, they are good as the work is clear, but not as far as we can depend on them for advises and what to modify, the only one that everybody recommended him locally, works only on American cars. This is why I am pleased we have 370z community :). After lots of research here I went with what I bought, but I didn't make it on time for the last track day of the season.

And he told me about that after he finished the work on my car lol. If he said it before I would go for a different garage.


Sent from my iPhone using Tapatalk