Majofo

I use a mason jar.

Yes, I know there's a chance it'll drop and break.

I hate cars

I'm way too clumsy to use one of those. The more I think about not dropping it the more likely I am to drop it. Just like the other day when I was walking up to work in front of one of the female interns. I thought to myself that would be embarassing to trip over the curb in front of her and guess what happened.

Majofo

It never fails.

Inaccurate

In the process of doing a brake job on mine. Using Racing Brake ET500 pads and Motul 5.1 fluid.



I used 3/16" tubing with a check valve. I discovered that the other check valve (labeled as "preferred") is much better than the other style (shown attached to tubing).

I had ordered three different style of check valves from US Plastic. I ordered the PN# 64108, 57172, and 64047. The one that worked best was the 57172 (click here).




Used a juice drink container for a catch bottle.




Strapped a rolled-up paper towel under the bleeder valve to catch leakage seeping thru the threads.








Pic of the old fluid. This is the first brake job and fluid flush for my TL since new. This dirty fluid has seen 5 years and 65,000 miles of service.

In Closing - I am withholding final judgment on this check valve method of bleeding brakes until after I have done a test drive. But on the surface, the check valve worked great today to do the flush. Very pleased so far with the check valve method. As long as the pedal is firm after a test drive to indicate no air was entrained via this method, I will fully endorse the check valve method.

I hope to finish the brake job in a day or two.

I hate cars

Looking forward to the review especially from someone who regularly sees ABS operation.

Majofo

That seems like a lot of fluid for one caliper.. tell me that's the front axle. At least your fluid wasn't green like mine. :troutslap

Roger555

iTrader: (3)

I just did my TL this past weekend basically thesame method as above but no check valve (one man operation). The only concern I had was air getting sucked in throuh the threads of the bleeder. The results were very noticeable though I had about an inch of play in my initial pedal travel that felt like it was doing nothing then it would start biting down. That is gone now I have immediate bite! Its much better!

SmileyOr

I'm planning on doing mine this weekend.

I want to cahnge the front brake pads along with the fluid change.

How do I go about the break in (seating of the pads) and the fluid change ABS brake test at the same time?

Is there a priority?

I know that first stop will be gentle . . . but for the second and third?

I just want to be sure I seat these properly so I have no squeel.

Brembo front brakes on my 07 TLS. I purchased Hawk HB530F.570 performance street pads.

Hacura

Should I be changing my fluid if I only have 19k miles, car is 4 years old and has never had it changed. I read it should be done every year after the third year.

nfnsquared

Yeah, I'd change it if it's been 4 years. The change interval specified in the Service Manual and the Owner's Manual is every 3 years, regardless of mileage during that time. At this point, your main concern should be to get any accumulated moisture out of the system by doing a fluid change.

I hate cars

Time is more important than mileage.

I hate cars

I had to run the AC today. I actually prefer a cold cold winter but it rarely gets below freezing here.

I've thought about what you mentioned with the 4 piston calipers before. The thing I can't get past is both the large single and smaller multiple pistons are still at the bottom of the system so I would think water would accumulate the same.

skh

Glad to see my suggestion worked Inaccurate!

My question now is what was the difference in the check valves? Was it just the cracking pressure and is that why you liked the 57172 better?

PS Great pictures Inaccurate! & if people are worried about air leaking in through the threads you can always put some type of sealant on the bleeders, loctite has may different flavors/or you can buy the exact same stuff speedbleeders puts on their from their website...

Now I have some questions for is for nfnsquared & Roger555. You guys just crack the bleed valve with a tube connected to it and nfnsquared says that he never has any problems bleeding his brakes that way... but from Roger555's post it seems to me like he got air in the line (it may have worked its way out) So to me it seems as if you need some type of check valve in order to keep the air out of your brake system while doing a one man brake job... (if you don't want to use some type of pressure system either positive or negative)

Thanks in advance!

nfnsquared

I use 1/4" ID clear tubing and it fits snugly over the nipples. I've never used 3/16" ID tubing as Inaccurate did. It must be very snug?

The curve in the tube keeps air from traveling back into the caliper. Air can travel back up the tube from the collection jar to the apex of the tube's arc, but cannot travel back down the other side of the arc into the caliper. The caliper side of the tube arc (about 5"-7") always retains fluid and no air.

The arc is more pronounced in the front calipers because the nipples are vertical (at least on the Brembo calipers, not sure about non-Brembos). It's less so (only about 2"-3") for the rear calipers where the nipples are not vertical. (Inaccurate's pictures are of the rear calipers. You can see the short arc that I'm referring to between the check valve and the nipple).

Does that make sense?

And if the tube is leaking at the nipple (which I don't believe as long as your tubing fits snugly over the nipple), then there's nothing a check valve can do to prevent that...

skh

Ahh that makes sense. Thanks for the quick reply!

Roger555

iTrader: (3)

I think you misunderstood. I only thought there could be a chance of air getting sucked back in though the bleeder screw threads, nothing to do with air in the tubing. The check valve is a nice idea but its not necessary at all because after 2-3 pumps the tube is filled with fluid when you release the pedal it only sucks back very little and it will be sucking back fluid not air. Back to the bleeder bolt though, depending on how loose the bolt is air can actually be sucked into the caliper through the threads regardless of how good a seal you have on the bleeder bolt nipple with your tubing. The only way to stop this would be to completely remove the bolts and wrap the threads with teflon tape which could be a bad idea if any of it were to fall into your caliper (I didn't do it). What I did was for the last set of pedal pumps I just tighten the bleeder bolt down so barley any fluid was pushing out which also meant more pressure on the screw threads and less of a chance air would suck through on my final release. Anyways when all was said and done I had a very stiff pedal and much improved braking and I didn't have to drag my Fiance out to the garage!! Win Win Oh and I did it all without removing my wheels or jacking it up! I might bleed them twice a year lol!

I hate cars

I did the exact same thing. In fact I did the whole thing where there was a little drag on the pedal and tightened the bleeder a little for the last few pumps. I think it's a good idea.

nfnsquared

That's why it's important to only crack the bleeder enough to get fluid out. I only go 1/4 turn.

Inaccurate

Correct. The 57172 worked better because of the higher cracking pressure.

I had first used the others with the lower cracking pressure. I saw bubbles coming from the open bleeder into the tubing (see pic). At first, I thought "I had that much air in the system? ". As I sit there watching it, I then realized that there was no way that much air was trapped in the system.

After a few minutes of scratching my head trying to figure out where the air bubbles where coming from, I came up with a plausible theory.



Given my setup in the pic above, it is easy to imagine how siphoning forces could be sucking air in thru the bleeder valve threads. That is, the siphoning force was greater than the cracking pressure of the check valve. The fluid was fallen down the tube and pulling air (via the bleeder threads) in behind the falling column of fluid.

After I switched to using the 57172, I had no more bubbles. Another bonus of the higher cracking pressure of the 57172 is that the higher pressure will push fluid out into the threads (displacing air). Then during the pedal's retraction, that fluid cache in the treads will hopefully be greater than the amount of air trying to enter thru the threads.


Lol. It does take some force to push the 3/16 onto the bleeder. I used the 3/16 because that was the closet size that I had on-hand. Later, I will try the 1/4.


Yes, this is my theory too. The check valve will offer resistance to push fluid into the threads. Hopefully more fluid will reside in the threads than the amount being sucked back inward so that the threads are never dry.

If my other theories are correct, the check valve is needed to prevent the column of fluid in the tubing from falling and thus sucking air (thru the threads) behind the falling column (aka, siphoning). Think of the check valve as an anti-siphoning valve.

BTW - I always open the bleeder by a 1/4 turn only.

This whole bleeding process is starting to feel like a high school science project

Inaccurate

SCIENCE PROJECT UPDATE

To test my siphoning theory, I conducted an experiment.

I filled the 16-inch tubing with brake fluid (similar to a mouth pipette). I placed the low-pressure cracking check valve at the top of the vertically hanging tubing. I released my finger from the bottom of the tube. Immediately, the fluid rushed out of the tube as if the check value was not even there.

I conducted the experiment again using the high-pressure cracking check valve (57172). The column of fluid remain suspended in vertically-hanging tubing.

The 57172 is able to hold the 16-inch column of fluid with just a ever slight leak. Thus, I will place two 57172 valves in series to make sure that the column of fluid is firmly held.

Based on these findings, I firmly believe that, without a 57172 valve, air is being drawn into the caliper via the bleeder threads by the hanging column of fluid. By the way, without the 57172 valve, this will still occur regardless if the end of the tube is submerged in fluid in the catch container.

But of course, the siphoning could be prevented without a check valve IF the catch container was positioned higher than the bleeder valve.

Roger555

iTrader: (3)

This is the way I looked at it. When the pedal is released the back pressure wants to suck back, and the fluid in the tube provides the least resistance so it sucks back a bit of fluid from the tube. If you make it difficult to suck back from the tube (check valve) then its going to search elsewhere for the path of less resistance which would make it more likely to suck through the threads and draw in air.

SharksBreath

iTrader: (33)

thanks for the pics and the write up. i'm going to be doing this very soon, as soon as weather allows.

anyway, if i go with a 1/4" tubing...would the check valve 57173 be the one to go with?

SmileyOr

I've taken some time to look at my rotors. They look and feel very smooth, except about 1/8" from the inside out there is a ridge of area not worn down by the current pads.

Do the rotors need to be turned?

nfnsquared

Nope, that ridge is normal.

SmileyOr

phew, that'll save some time calling around today trying to find a shop that will turn them this weekend.

Now for my other questoin that has yet to be answered clearly. When I change the pads AND the fluid at the same time, is there a break in procedure first or just test the peddle pressure for possible air before seating the pads with the hard braking with consecutive stops from 60 mph?



TIA guys!

Roger555

iTrader: (3)

I would do the fluid first if you want to activate the ABS then pads and break in

nfnsquared

Yes, there is a break-in procedure. It should have been included with the pads.

Which to do first, VSA or break-in? Don't really think it makes a difference, but I'd find a dirt/gravel road (or snow covered road) and do the VSA first. You don't need to be going fast for this (20 mph or so), just fast enough to engage the VSA a couple of times on loose/slick surface.

If your peddle pressure goes down after doing this, then go back and re-bleed (and re-engage the VSA, check peddle pressure) before proceeding with the break-in.

SmileyOr

The check for air can be done on the new pads?

Roger555

iTrader: (3)

I wouldn't try and activate the ABS on new pads

SmileyOr

Allright, I'll use the ramps and try to bleed the brakes without taking the wheels off.

Thanks for the advice!

nfnsquared

What's your reasoning? Just asking...

nfnsquared

Huh?

Hacura

Where do you guys pick up your Motul 5.1 from? I can't seem to find it locally...

Thought this was interesting, have been reading that some people feel the Motul 4 RBF-600 has a higher boiling point and is the best. Found this link on boiling points from a Vette forum, funny I got a buddy from the military that always repeats "the Vette gets them wet" lmao:

http://www.seinesystems.com/BrakeFluids.htm

I hate cars

I ordered mine. Motul 5.1 does not have the highest boiling point but you will never need the highest boiling point offered on the street. What it does do is improve the response of the ABS because it's much thinner than every other fluid. This is the one fluid that has the potential to improve one stop stopping distances.

With that said, I'm going with Castrol SRF next time. The wet boiling point is just too good to pass up and my car does see track duty once in a great while.

Roger555

iTrader: (3)

All Im saying is if you put new pads on they should be broken in before you try to perform a hard stop to activate ABS because they are not bed in yet none of the pad material has transferred to the rotor. How much will it matter? Who knows just saying I would follow the procedure.

This is what I follow
http://www.stoptech.com/tech_info/wp...formance.shtml

Bedding-in Street-Performance Pads

For a typical performance brake system using street-performance pads, a series of ten partial braking events, from 60mph down to 10mph, will typically raise the temperature of the brake components sufficiently to be considered one bed-in set. Each of the ten partial braking events should achieve moderate-to-high deceleration (about 80 to 90% of the deceleration required to lock up the brakes and/or to engage the ABS), and they should be made one after the other, without allowing the brakes to cool in between.

Depending on the make-up of the pad material, the brake friction will seem to gain slightly in performance, and will then lose or fade somewhat by around the fifth stop (also about the time that a friction smell will be detectable in the passenger compartment). This does not indicate that the brakes are bedded-in. This phenomenon is known as a green fade, as it is characteristic of immature or ‘green' pads, in which the resins still need to be driven out of the pad material, at the point where the pads meet the rotors. In this circumstance, the upper temperature limit of the friction material will not yet have been reached.

As when bedding-in any set of brakes, care should be taken regarding the longer stopping distance necessary with incompletely bedded pads. This first set of stops in the bed-in process is only complete when all ten stops have been performed - not before. The system should then be allowed to cool, by driving the vehicle at the highest safe speed for the circumstances, without bringing it to a complete stop with the brakes still applied. After cooling the vehicle, a second set of ten partial braking events should be performed, followed by another cooling exercise. In some situations, a third set is beneficial, but two are normally sufficient.

nfnsquared

^^^^Yeah, but this type of ABS stop is slow speed, low energy on a deliberately slick surface. The only goal is to lock the wheels so the ABS will activate and force fluid through the metering valves. This shouldn't have any effect on the pads/rotors.

Majofo

SRF is seriously expensive. There's no way I'd use it.. lol. When you said expensive I thought ~$35 / qt. It's more than double that.. should have known, it's the bf most porsche owners use.

studville

Quick Question, when you guys are using the one man/two man brake pumping method (ie no fancy gadgets). Do you remove the master cylinder cap while pumping and draining or does that remain on?

Does anything need to be done with the e-brake on an AT?

nfnsquared

I leave it off, but wrap the opening with paper towels just in case. I've never had a problem with BF spilling out.

The p-brake is all mechanical. There is a major and minor adjustment procedure if it's loose. Do a search for "p-brake" or "parking brake". Both procedures have been posted.

Inaccurate

Yes sir. The 57173 is the valve for the 1/4 tubing. Order a lot to cover shipping and for future use. I would expect the fluid to chemically attack the housing and Buna-N seal material after a few days. So, I would trash a valve after a bleeding session.