BAD product. Period. There's no separation of the pressurized air and the fluid. So, guess what you're doing?.......You're actually putting air into your brake fluid. BAD, BAD, BAD.

Cheap pressure bleeders are just plain lousy and extremely bad to use. Check with any reputable brake caliper, pad, or fluid manufacturer and they'll tell you the same thing. Just because something is sold on the open market, that doesn't make it a good thing.

 

Have you actually used one? Have you had problems with it?

There isn't enough pressure (10 psi or so) to saturate the brake fluid with much air beyond what is in there all ready from the can...I am sure there are some fluid properties tables out there that can give precise air vs pressure saturation data for brake fluid and I would need to see from those that this is really a problem before I trash the one I have.

As that goes, I have not seen any problems with the one I use and agree with kukaepe. It is well worth the money. It is a heck of a lot easier to use than the 2 man method and much better than vacuum bleeders that I have had suck air into the lines.

 

I would have to agree with Eddie on this. I have used this since the late 1990s and have no trouble with it. In fact, for the past four years, I have been using it on my track car and has had no trouble with air in my brake fluid. If it were a problem, it should show up on the track. I remember one time for a PCA event a few years ago, I brought it to a mechanic and he boiled a sample to look at water content in my brake fluid and air in my brake system and said it was OK.

Martinb, Can you provide some links to show that manufacturers advise against the Motive product as per your claim.

This topic has been discussed in great length with Todd from TCE Performance in another thread a year or so back. While he likes the two person method, I do not remember anything that says your brakes will be in jeopady if you use a pressure bleeder.

 

I'm trying to find the articles that I read but it's been awhile. I do note that StopTech has a white paper devoted to bleeding and they put forth the manual bleed method. (FYI: StopTech has some great white papers. One talks about the effect of big brake kits on ABS and stability control systems. Very interesting.)

What I remember from the articles I read was that pressurizing the fluid when the air is in contact with the fluid actually forces more air (and thus moisture) into the fluid. Will it make a difference that you'll notice on the street? Probably not. But nevertheless, when using these less expensive pressure bleeders where there's no bladder or diaphram to separate the fluid from the air, you're putting more air into your system than you would be otherwise.

 

Thank you for looking for the information. I have been reading a fair bit about braking systems before I put on a BBK. And more accurate information is always welcome.

While I think it is certainly possible, I think it would be quite difficult to squeeze much extra air into brake fluid at ambient temperature, 10-15 psi of pressure and only 45 minutes or less of pressurization to matter much.

 

I may have overstated, in my original post, the importance of not using the cheaper bleeders without the separation between the air and fluid, but I do know that it's not the best way to go about it. (Got carried away with enthusiasm.)

What I found more interesting was that white paper by StopTech regarding the effects of slapping on big caplipers and how doing so can adversely affect the performance of ABS and stability control systems. I'd always suspected that it's best to not muck around with ABS systems too much and now I know why. I wonder if companies like Brembo and BBK, etc., take these things into consideration when specing and selling big brake kits. It seems that StopTech is very aware of this and does everything they can to make sure that their calipers work in harmony with a particular car's entire braking system.

By the way, BR Racing in Los Gatos, California, where I've had some work done, highly recommend StopTech. They prefer them over Brembo and others for many applications.

 

Interesting read (stoptech's whitepaper). Nice find.

But with a little careful reading and discussion with some brake suppliers you will find, for example, that the Wilwood BBKs are very similar to the stock (at least for the smaller setups). The rotor size is the same or slightly larger and the piston area is the same; Wilwood gives you the piston area which StopTech does not (at least not that I could find). Given the similarity to the stock set up, the Wilwood should be a similar type of setup that StopTech is doing. And be, likewise, system compatable.

However, one difference is that the Wilwood setup will fit smaller wheel sizes. The StopTech requires a 17" wheel; the Wilwoods will fit down to 15". For me that is important as I need to run a smaller wheel/taller tire setup for the roads around here. So I run 16" wheels on the street. 17" for the track and autox. The Wilwoods will fit that with a very nice setup that will also be good for my other activities.

So there are some good options out there, recognizing that not going overboard, as the StopTech paper discusses, is important.

 

There's always some legitimacy to info put forth by any manufacture. But don't over look the underlying fact that any company is using what they have to offer as a tool to sell you something. ST certainly produces a fine product but it's just as easy to apply that same 'over enthusiasm' as was the bleeder comments. Just because you read it on a web page doesn't mean it's all true. Or at the least subject to some interpretation.

There are many companies who produce well designed kits for your car. Some shine in areas that others don't and visa-versa. For the novice who jumps into the Summit catalog blindly there could be some issue...