cncnut

Mechanic recently told me I needed new front brakes, and he pointed to the master cylinder showing fluid level low. I said no and went on my way. I've attached a photo of the brake pads I inspected today. Everything looked like normal wear nothing abnormal. Any opinions? I have about 6-6.5mm of pad left to the metal plate. From what I understand the factory pads are between 8 and 10mm. (correct me if I'm wrong)

Was this just a complete con or overzealous pitch to make some quick cash? The rotors aren't bad, normal wear it appears and no real pitting. I will change them when I eventually change the brake pads.

Also is the fluid level in the master cylinder even a shot from the hip to tell the brake pads are worn? And since I'm new to a lot of this stuff, how should I approach the fluid level, just fill up the cylinder to the max level with standard Honda OEM brake fluid? Thanks!

ezone

Your parts changer never actually looked at the brake linings?

cncnut

Not that I know of. He didn't even have the car up on the lift.

ezone

First pic, I think that inner pad looks like it's about 3mm or so, I'd say they will need brakes soon, and to inspect over the next couple oil changes and pay attention to any noises (wear indicator squeal).





Next 2 pics, I'd say these are due.
About 1mm until it hits the wear indicator.
2mm to steel.

ezone

So was the fluid at the low line?
Was the red brake light coming on on the dash? (it may come on when the fluid is halfway between min and max)

Mechanic didn't consider that low fluid might be a leak?
What he calls "low fluid" isn't really low at all?

Yes, pad wear will result in the reservoir fluid dropping but that's not the only possible reason fluid level may drop.
Fluid level will return when new brake pads are installed, due to pistons being pushed back in (unless fluid leaked out).

Brake jobs are gravy money for mechanics.

You probably know where I'm going with this....

mac25

The brake master will drop in level as the pads get used up. when the pads get low there is more travel space between the pad and the rotor, which causes the brake master cylinder to drop in level.

It could be that who ever did your pads before didn't top the cylinder up to "full," which makes the cylinder look ever lower now that the pads are at 60%.

not sure, just a guess.

cncnut

Thanks for all of the input guys, I had a feeling that the fluid worked in that manor as it is logical. But I have always heard that eye balling fluid level like that to determine brake wear is like a shot from the hip and as you said it could be a leak too. I didn't see any leaks on the lines on the front brakes but perhaps I should give the entire system a once over to be certain. I've attached a side view of the master cylinder. Would you say this level is normal for brakes about half worn in a worst case scenario? Should I avoid topping this off and address the fluid on the next brake change to see what the actual levels will be with fresh brakes? Thanks!

cncnut

Btw for what it's worth it was a car I purchased used from a honda dealer, it was serviced by honda it's whole life and low mileage for it's age, which was why I was skeptical that it might need new brakes, as I just purchased it a few months ago and in my state you can't sell a car with less than 50% brake pad wear.

ezone

Right. Low fluid level only means the fluid level is low, but it would be an indication the brake linings need to be inspected.

There SHOULD be some investigation to determine the cause, because it probably did not evaporate.

Simply push the piston back into the caliper body all the way (on both front calipers) and check the level of the fluid in the reservoir, that's your fluid level @ brand new brake height (less the first couple of pumps).

Rear shoe wear has little effect upon fluid level.
If you had rear disc brakes, it would.


I figure that on most systems, the reservoir was sized and the fluid level sensor was placed such that the fluid level could be set at the full line with all new brakes, then by the time the disc brake pads are worn to replacement range, the fluid level has dropped just enough to turn on the low fluid warning light.
This does not a hard and fast rule, it does not always work as planned, and it cannot work if anyone tops off the reservoir during a service. Do NOT rely on the warning light to indicate the need for brakes!

Visual inspection is always the best way to determine needs.
Interesting.
I was under the impression that areas with a mandatory inspection had a minimum thickness measurement spec for brakes.

How can anyone know what 50% is when the thickness of brand new brake linings is rarely known?
I prefer to work with actual thickness measurements when I check brakes for customers, much like in the pics above.
That's about right for most of Hondas pads (not shoes), but certainly not all cars.

Large cars, seems like some German cars, and certainly many trucks use brake pads that begin life thicker than what I'm used to seeing in Hondaland. Others I've encountered start out quite a bit thinner than what I would have expected.

I think the rear pads on my Harley start out new at about the same thickness I would be recommending a brake job on Hondas. If all I ever knew were small Asian cars, I might never know to judge others differently. The rear pads on my bike seem to need replaced at about the same time I wear out the back tire LOL