I just got my Hawk front pads in today, and I was wondering if you had to drain the brake fluid and put fresh fluid in?

The reason I am asking is the instructions say to do that.

And please, no funnies, I am a non-mechanic here, LOL.

Also I was wondering about the blinker fluid, when does that have to be changed?

 

It is not mandatory to replace the brake fluid every time you swap pads. I do it only because most cars I work on have had the brake fluid neglected. I figure I might as well take the opportunity to change the fluid, since I've got the wheels off anyway.

The brake fluid should be changed every two years from the date of MANUFACTURE of the car with fresh DOT 4 fluid. That's for a car that sees only street driving. If you are taking your car out on the track, it's important that the fluid be fresh, since the boiling point declines over time as moisture is absorbed by the fluid.

If your brake pedal is soft or if you've opened up the hydraulic system for any reason (opened bleed screws, replaced master cylinder, etc.) then you need to bleed the brakes in order to get any air out of the system. Air is compressible and will result in longer pedal travel. Brake fluid is not compressible.

 

Excellent, thanks for the response. Guess its just changing the pads only. Thanks again

 

If you replace the fluid every time you change the pads (once a year or so the rate I am going), would it be good enough to just suck the fluid out with a turkey baster in the master cylinder and just replace that? I would assume that there isn't much fluid in the lines and ABS system that it would really cause a problem?? I was thinking of doing that and replacing it with some DOT 5 fluid...that way I will get like DOT 4.75

Bad idea??

 

I think it's the fluid closest to the calipers that you need to worry about the most. when your calipers get hot, any air/water in the lines near the calipers will cause poor performance.

I suspect just swapping out the reserve by the master cylinder would show almost no improvement.

 

Very bad idea! DOT 5 fluid is not compatible with DOT 4, nor will it work in a modern car with ABS. Because it is silicone-based, it is compressible and will always give you a soft pedal feel. In addition, it can be aerated by the motion of the ABS solenoids and you will experience total loss of system pressure after ABS engagement.

As for changing JUST the fluid in the reservoir, that's also a bad idea. It's the fluid in the calipers that needs to be fresh. Moisture gets in around the caliper piston seals and it actually does permeate the rubber brake lines. As the fluid gets saturated with moisture over time, the boiling point is reduced. You need FRESH fluid in those calipers to keep the boiling point high and to prevent corrosion.

 

I just replaced my fronts with Axxiss Ultimates and the rears with Porterfields. I didn't replace the fluid because my fluid hadn't arrived yet. I couldn't be happier with the results. I did proper bedding of the brakes and I have no squeel. They are definitely strong and work well.

This weekend I'll be bleeding the OEM fluid out and replacing it with ATE Super Blue, since I will be doing some casual track driving with the car (which is why I replaced the pads with something stronger and more heat resistant).

But prior to replacing the fluid, the brake job alone worked great. My car is nine months old and has around 15k miles on it.

 

What is the reason for DOT 5 fluid then? I seem to remember the Porsche guys talking about it since it had such a high boiling point. It seems almost worthless then???

So, DOT 4 fluid is what you would recommend for anyone???

 

DOT 5 fluid is used in antique cars, since it does not absorb any moisture. It is also used by domestic motorcycle manufacturers, such as Harley Davidson. It is completely incompatible with DOT 3, DOT 4, and DOT 5.1 fluid. If you get any cross contamination, it will result in coagulation of the fluid. This would be a very bad thing!

Your Porsche buddies were probably talking about DOT 5.1 which, despite the similar name to DOT 5, has absolutely nothing in common with it. DOT 5.1 was introduced during the initial deployment of automotive ABS systems and has a lower viscocity than DOT 4 and DOT 3. Not all DOT 5.1 fluids have a higher boiling point than all DOT 4 fluids, so going up in DOT numbers is not always an upgrade.

Stick with DOT 4 fluid and make your selection among them by picking the one with an appropriate boiling point for your application. If you are tracking the car with StopTech or Brembo brakes, you can probably get away with ATE TYP 200 or ATE Super Blue Racing. If you are tracking with your factory brakes (non-Track models), then you should use Motul 600 or Castrol SRF which are more expensive than ATE fluid, but boil about 50 degrees higher. Your stock brakes will run much hotter than the StopTech or Brembo aftermarket brakes, so you need all the protection against boiling that you can get.

 

Overall, at $15 for a pint of the most expensive stuff, it's cheap insurance. Take the time and do it right. In the process you will get a feel for you car and working on it. Before I got my Z I hadn't worked on a car in 10 years. Now it takes me 1 hour to bleed and replace with new fluid and change pads. Personally I use Motul RBF 600 (~$15) and have had no problems and rock hard pedal feel. As for your original question, you should probably do it once a year, 2 a year if you see some track time.

 

Where would you guys recommend getting the Motul 600??? I figure might as well get the good stuff if you are going to change it!!!

Thanks for all the help!

 

I sell it, but I don't have the best price out there. If you are ordering JUST brake fluid, you would be better off getting it from Motive Products. They bought a large batch of the stuff and are selling it for just $9.95/bottle. Since it has a 2-year shelf life (plastic bottles, not metal) it's OK to buy it there now, since it's about 6 months old. But if they are still selling it at that price next year, you might want to steer clear.

Motul raised the list price to $15 (and raised wholesale prices too) and told us we couldn't advertise pricing on the Internet at below list. Anyone who has inventory of the old fluid can advertise it at whatever price they want. I want the fluid I sell to be as fresh as possible, so I don't inventory more than a handful of botttles and the rest are drop-shipped directly from my supplier. Thus, I'm stuck paying the higher price and my prices are not competitive with some of the big vendors who have stockpiled it.

For some reason, Motive Products still shows a picture of the old style bottle of Motul and they list the old formulation's dry boiling point of 585 degrees F. The new stuff is 593 degrees and the bottle is different. However, Motive Products is selling the newer stuff. Otherwise it would be 3 years old!!


New style of Motul 600


Old style of Motul 600

 

Ok, last question, how much is needed for the whole system? I am doing my brakes soon, so I might as well change the fluid while I am in there....

 

I can do a complete flush of the system with just slightly over 1/2 liter. But I've done it a zillion times. It would probably make sense, if you've never flushed the brakes before, to have 1.5 liters of fluid on hand.

 

I used 1.2 bottles when I replaced my calipers and drained the whole system. After that, I use a whole bottle when I bleed. It needs no where near a whole bottle, but the stuff is so hydroscopic, it probably doesn't do any good to keep a half empty bottle on the shelf of my garage. After you replace the fluid, engage ABS a few times to flush out the old stuff. The next time you change it will all be out. Don't worry about cross cantamination of the old stuff b/c the stock fluid is compatible and the 5cc still left in the ABS won't hurt you. DZeck- please correct me if I'm wrong.

 

You are correct. Only one minor nit, and that's that there is no such word as "hydroscopic." It's actually "hygroscopic."

 

zand02max, do you have any squeeling with the Hawks?

 

Blinker fluid is fine, but you are overdue for headlight and swaybar fluid changes and you need to bleed your shocks.

 

I've been extremely happy with my Axxis Ultimate (front) and Porterfields (back) so far. They are slightly more aggressive, but are smooth and squeek-free.

I'll have it on the track on Monday, so I'll have a real report after that. :-)

 

I think the carburetor bearing needs to be greased Oh, and don't forget to rotate the air in the tires!!!!