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Best bleeder screw? Does that exist?

TMSBOSS

Spending my pension on car parts and track fees.
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I like bleeders which are two piece having one section which seats in the caliper and stays in place. You turn and release fluid by opening a smaller bleeder imbedded in the outer section. Each time you bleed the brakes, the moving/wear parts are parts of the two piece bleeder. Nothing on the caliper wears.

 

PaddyPrix

If breakin' parts is cool, consider me Miles Davis
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San Diego
@PaddyPrix might have some info in this area.
TMSBoss beat me to it.

The metal is pretty soft, and I'm assuming the screw wears down, I semi-religiously changed my fluid after every other event, sometimes if I was pushing the hell out of it at ACS which is also brutal and will dayglow if you get it up there. I won't have test data on those new thingies, but the outer stays solid, and the inside has a nice spring-loaded ball that takes a lot of the wear and tear out of it.

If not, you're probably going to enter a world of pain.

 
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I've been using Stahlbus brake bleeders for about the last 15 years. Nothing better is available. Forums get all wound up about one-piece cheap products that work a little bit for a while. The Stahlbus units just work and work and work. Of course, I might be biased, having their stuff on all four of the family cars, both oil drain valves and caliper bleeds.
 
270
413
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3-5 Years
Wisconsin
I like bleeders which are two piece having one section which seats in the caliper and stays in place. You turn and release fluid by opening a smaller bleeder imbedded in the outer section. Each time you bleed the brakes, the moving/wear parts are parts of the two piece bleeder. Nothing on the caliper wears.



These?

Will the motive bleeder still work?
 

PaddyPrix

If breakin' parts is cool, consider me Miles Davis
663
970
Exp. Type
Time Attack
Exp. Level
Under 3 Years
San Diego

These?

Will the motive bleeder still work?
Well, sure, but kinda becomes less valuable with this technology, right?

1669735613379.png1669735629446.png

The Motive works by you going up to the Master Cylinder, pumping up and building pressure. Then you go to the brake caliper and loosen the screw, which will then allow the fluid and air to push through. At this point, it's no different because it's just pumping for you. With the spring putting constant pressure against the ball and the lower half, if you didn't have a Motive Power Bleeder, you could just walk over and give it whatever, 10 pumps, and as you let off, the spring will apply pressure against the ball to close and keep the line pressure. This technology is taking the place of the person who'd be closing the bleeder valve, so I guess it really just saves you the short walks out and over to the passenger side.
 
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The way Stahlbus bleeders work is that if you open the valve 1/2 turn from closed, the inner spring holds the valve closed and you have to put pressure in the brake line to push fluid out the vent on top. As soon as you release the brake pedal, the valve shuts, keeping air out. This way you get a good quality pressure bleed - the brake pedal takes considerable effort to open the valve. You can back the valve out two full turns if there's a need to do a flush with a Motive or whatever, but generally there's no real benefit to that approach. You could use a combination of Motiv and the Stahlbus bleeders - fill the Motive up and apply light air pressure so you can use it to keep the reservoir full while you do the rest. I've never done this on my car, but I don't see a reason it won't work.

Here's how I do a full flush on the GT350:

1. Reservoir: suck the fluid out of the reservoir to just above the fittings and replace it with fresh fluid. Mix it a bit and then do it again. Twice is enough. You now have fresh fluid in the reservoir.

2. The right rear: at the RR corner, back the inside bleed screw out by 1/2 turn. Put the catch bottle on and pump the brake pedal 16 strokes, taking care not to empty the reservoir. Then snug the inner bleeder valve and move to the outside bleeder and do 8 strokes, then back to the inside bleeder for 8 more and then finish with 8 more outside. You now have fresh fluid in the hard line from the reservoir to the rear axle as well as the RR caliper.

3. The left rear and the front calipers: it takes fewer pumps because all you're bleeding is a short hardline and the caliper. Do 12 strokes on the inner bleeder and 8 on the outer.

A note on torque: install the bleeders as instructed with about 100 inch-pounds torque on the 10mm outer screw. The smaller upper screw, the valve, is 8mm and it's tight at 80 inch-pounds. When I'm doing a bleed, I hold the main screw with a 10mm box wrench so it can't unscrew and then I use an 8mm deep socket to manage the bleeder valve screw. When I'm switching from inside to outside, I only "snug" the bleeder screw to the point where it stops turning. That closes the valve so it won't leak while you're bleeding the other side of the caliper. Once I've done both inner and outer, I use a torque wrench to set the requisite 80 inch-pounds.

This method uses more fluid than most people are used to using, but I've validated it with a brake fluid moisture meter and with these stroke counts, brake fluid is coming out fresh on all 8 bleeders. You can do it with less and it'll probably be fine, but I figure brake fluid's cheap compared to everything else, so I'm ok with that.
 
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Do these have a torque spec?
The operating manual is here: https://www.stahlbus.com/info/images/Downloads/Stahlbus_Bedienungsanleitung_10_2017.pdf

They say 10 newton-meters for the 10mm install torque and 8 newton-meters for the valve torque. That's 88 inch-pounds and 70 inch-pounds respectively. I just round up to 100 and 80 because it's easy to set on my wrench.
 
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@JAJ

Thank you for the write up!


I did forget to ask. I have the S550 swapped Brembos. These will work with that right?
So long as you have the right thread and length, they'll work with any caliper. I've used them on Brembo Racing, Stoptech, OEM Ford Brembo, OEM Ford S197 rears, AP Racing, etc. If you like these, try the oil drain plugs they make. I've got them on all the family cars. Makes oil changes simple and clean. Even the GT350 has a Stahlbus drain plug, but it's not on the engine, it's on the transmission drain. It seals when you unplug the hose. That allows me to drain the gearbox with a drain hose, switch to a fill hose and pump it full it again from below. Quick, easy and very un-messy.
 
Thanks for turning me onto these, as they seems like a great option for a 1-man-show. I ended up taking my bleeders out of the calipers to measure and confirm I ordered the right sizes and after a conversation with Stahlbus USA ended up with M10x1.0 with 16mm under-head depth for all corners. I set my vernier calipers to 14mm originally and compared them to my bleeders, but the vernier jaw came up noticeably short of the end of the conical bleeder seat. Stahlbus made a note that the hex-head portion of their bleeder shouldn't be in contact with the caliper body in order to ensure their bleeder is seated correctly inside the caliper, so they advised the 16mm version for my application. I was measuring the GT500 6-piston caliper bleeders and the stock single-piston S197 rear brake caliper bleeders - both of which were identical in all dimensions.

I took some reference photos to aid our conversation, so I can share them here as well. These are from the rear single-piston S197 caliper bleeder, although in my measurements both the front and rear bleeders were identical as mentioned before.
Testing @ 14mm under-head depth
1670420896472.png
Testing @ 16mm under-head depth
1670420938474.png

Closest match for my application was the below Stahlbus bleeder design.
1670421334019.png
I assume there's some variance based on model year and what brake packages the vehicle has, so I'd suggest if anyone wants to also pursue these bleeders that they pop the stock ones out and measure them up for piece of mind.
 

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