bleed tool

[Gmc28]

wondering if anyone has any tips to share on using one of the motive flow (or similar brand) brake/clutch bleeder tools on the v11’s, in regard to how to fit the bleeder to the reservoir.

they don’t seem to sell the “plug and play” options for attaching to the reservoirs so you have an airtight seal and the hose inlet from the pump-up container.  i rigged up a frankenstein setup for my son’s Cagiva, using an extra reservoir cap i had and drilled to allow a fitting for hose input, only to find that the threads weren’t quite the same on the cap i found in my parts box, so it wasn’t air tight.  figured i’m probably missing something simple, as a lot of folks use these, and i’m just missing the obvious.   maybe a plate that you drill with a hose fitting, and clamp in place?

Bleeding by hand is what i’ve always done, and no problem, but figured i’d try and get this device to work right for me for longer term.  (got it figured my old ford diesel… plug and play attachment, and thats helpful for a system with that much fluid)

I think Phil uses one of these on his MG?

[gstallons]

I will have to look and see what is needed (once it gets daylight) and get back on this . I have a Mighty-Vac and a Phoenix brake bleed tool and a drawer full of mess to help w/my attempts . If you have extra reservoir caps you may be able to rig up something to pressurize the system to push the fluid out of the system . I've bled all mine w/a simple method and didn't use a bunch of stuff. It might not hurt to do this on a annual or biennial  basis . AND be sure to use fresh DOT-4 fluid . 

[LaGrasta]

I've been using a generic version of this tool for over two decades, for both cars and bikes. It's awesome and easy.

 

https://www.amazon.com/Motion-Pro-08-0143-Hydraulic-Bleeder/dp/B000MXW2EM?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=ATVPDKIKX0DER&gQT=1

[Lucky Phil]

19 hours ago, Gmc28 said:

wondering if anyone has any tips to share on using one of the motive flow (or similar brand) brake/clutch bleeder tools on the v11’s, in regard to how to fit the bleeder to the reservoir.

they don’t seem to sell the “plug and play” options for attaching to the reservoirs so you have an airtight seal and the hose inlet from the pump-up container.  i rigged up a frankenstein setup for my son’s Cagiva, using an extra reservoir cap i had and drilled to allow a fitting for hose input, only to find that the threads weren’t quite the same on the cap i found in my parts box, so it wasn’t air tight.  figured i’m probably missing something simple, as a lot of folks use these, and i’m just missing the obvious.   maybe a plate that you drill with a hose fitting, and clamp in place?

Bleeding by hand is what i’ve always done, and no problem, but figured i’d try and get this device to work right for me for longer term.  (got it figured my old ford diesel… plug and play attachment, and thats helpful for a system with that much fluid)

I think Phil uses one of these on his MG?

I made some from old reservoir caps and QD air fittings as my Motive bleeder has a QD hose that I also made myself with with air fittings. Motive sell a bleeder with QD fittings but at the time I was saving money as the bleeder was expensive to ship from the US. Now you can buy them cheap on ebay or Aliexpress. I'll see if I can get an image of my home made adaptor. 

Phil 

EDIT... Here's the front adaptor I made complete with home made seal.

Edited December 31, 2024 by Lucky Phil

[Gmc28]

On 12/31/2024 at 1:02 PM, Lucky Phil said:

I made some from old reservoir caps and QD air fittings as my Motive bleeder has a QD hose that I also made myself with with air fittings. Motive sell a bleeder with QD fittings but at the time I was saving money as the bleeder was expensive to ship from the US. Now you can buy them cheap on ebay or Aliexpress. I'll see if I can get an image of my home made adaptor. 

Phil 

EDIT... Here's the front adaptor I made complete with home made seal.

nice. just what i was looking for.  

i actually scrounged some of the same fittings and have been sitting on those awaiting an idea of what to install them on, as i don’t have the right cap.

I rigged up something less ideal with what i had in the shop at the time, but the weak link was having the wrong spare reservoir cap.  I’d have thought it would be easy to source replacement caps, but it’s proving surprisingly tricky.  and since i have a number of different reservoir styles/shapes, am wondering if some kind of clamp on setup could work.  

thx all

[Lucky Phil]

3 hours ago, Gmc28 said:

nice. just what i was looking for.  

i actually scrounged some of the same fittings and have been sitting on those awaiting an idea of what to install them on, as i don’t have the right cap.

I rigged up something less ideal with what i had in the shop at the time, but the weak link was having the wrong spare reservoir cap.  I’d have thought it would be easy to source replacement caps, but it’s proving surprisingly tricky.  and since i have a number of different reservoir styles/shapes, am wondering if some kind of clamp on setup could work.  

thx all

Just buy yourself some nice aftermarket caps on ebay or something. They are a dime a dozen and are anodised as opposed to powder coated. Then just modify your old caps.

Phil

[gstallons]

BTW , apply just enough air pressure to cause a good flow of liquid through the hydraulic system .

[Gmc28]

Old topic, but the nuisance issue i'm having hasn't gone away.  

Next step is that i'll try another version of a lid for the reservoir, as the one i got cheap online and which seems to fit just fine, gushes brake fluid out through the threads.  Made a decent home-made seal/gasket, and same issue.  Must be threads on the cap that are "just exactly wrong" to look and feel right, but actually causing it to go on a bit crooked.  odd.    I'm thinking a larger cap that assures i have a clean, flat interface with top of the reservoir, and a decent seal/gasket, then clamp it in place, and that should work.

However, the core issue is more the question for anyone who wants to weigh in, which is related to why the system won't bleed, even the "old fashioned way".  I've bled lots of brakes, and always the same technique (squeeze, twist/open, twist/close, release, re-squeese... slowly), with the only question being how much patience was required.  But this Cagiva clutch setup came to me from my son with no action... just a smooth, no-resistance pull on the clutch handle.  it would barely bleed when i checked it, so i "shotgunned" the decision that it was the master, and replaced it.  no change.... it would bleed a little fluid, but barely, after a lot of bleed action.  ok, so i popped on another slave i had laying around from another old Duc i had which cross referenced (it worked when it came off), and now after a hundred (?) pulls to bleed it manually, its just a tiny spurt of air at the bleed/lower end each time, never even a hint of fluid.  Bled the master first, just to assure it was coming out of the master at the banjo fitting (which introduces air, of course), then a zillion pumps later its the same spurt of air but no fluid movement. 

Technique flaw?  Never had this issue before, having replaced a good number of slaves, but this simple issue has me scratching my head.  the solution to push fluid through using the new contraption had been just a nifty way to enhance the process, but now i see it as a way to validate that all the air is gone by pushing fluid through, so thats where i've become focused.  I also have an old, old suction version of the brake bleed tool, which I never liked, but may try that just to eliminate some variables.

[PhillipLarsen]

Your bleed issue reminds me of a front brake problem bleeding I had on my Norton 850 that was all original. Many similarities. So simple system, but was not responding, decided to swap out master for new, then slave for known rebuilt good one off the back, still problem. Only thing left was the brake line, which was two rubber lines and a metal line in between. The rubber lines were the issue breaking up inside, causing intermittent problems. Changed all the lines and was like new. 

[Gmc28]

2 hours ago, PhillipLarsen said:

Your bleed issue reminds me of a front brake problem bleeding I had on my Norton 850 that was all original. Many similarities. So simple system, but was not responding, decided to swap out master for new, then slave for known rebuilt good one off the back, still problem. Only thing left was the brake line, which was two rubber lines and a metal line in between. The rubber lines were the issue breaking up inside, causing intermittent problems. Changed all the lines and was like new. 

makes sense.  had occured to me that the metal sheathed line could somehow be the core issue, but figured since there's no fluid leaking at all, that the line is ok.  but perhaps there is a compromised line which allows air in, but doesnt' necessarily let fluid out. 

[Lucky Phil]

Not sure if I've mentioned this before but I've been trying to understand why tying the brake lever on overnight significantly improves the lever feel after bleeding. I've had the question in my mind for a few years but never had an answer. My only thought is that the constant brake pressure over a longish period dissolves any formed air bubbles back into solution in the brake fluid where they don't have an effect. In other words the compressibility of a formed air bubble is different to the same amount of air suspended in solution in the brake fluid. Naturally this has to be within reason but I wonder if it's like the fuel drain checks I used to do on jets earlier in my career where the water suspended in the jet fuel wasn't a major issue until it was enough to separate out of suspension into straight water with a dividing line with the fuel. Same concept but different.

So the question is does a quantity of dissolved air or air molecules suspended in a given amount of fluid in a sealed system have less affect on the compressibility of the fluid than the same amount of air in a formed bubble within the same system.

It's in the realms of a scientific question and I've not been able to find an answer. I need a physicist. Any takers to answer this?

Enquiring minds need to know.

Phil

Edited Monday at 10:02 PM by Lucky Phil

[Gmc28]

3 minutes ago, Lucky Phil said:

Not sure if I've mentioned this before but I've been trying to understand why tying the brake lever on overnight significantly improves the lever feel after bleeding. I've had the question in my mind for a few years but never had an answer. My only thought is that the constant brake pressure over a longish period dissolves any formed air bubbles back into solution in the brake fluid where they don't have an effect. In other words the compressibility of a formed air bubble is different to the same amount of air suspended in solution in the brake fluid. Naturally this has to be within reason but I wonder if it's like the fuel drain checks I used to do on jets earlier in my career where the water suspended in the jet fuel wasn't a major issue until it was enough to separate out of suspension into straight water with a dividing line with the fuel. Same concept but different.

So the question is does a quantity of dissolved air or air molecules suspended in a given amount of fluid in a sealed system have less affect on the compressibility of the fluid than the same amount of air in a formed bubble within the same system.

It's in the realms of a scientific question and I've not been able to find an answer. I need a physicist. Any takers to answer this?

Enquiring minds need to know.

Phil

I like it... thats the question/topic I more commonly am interested in when I'm bleeding systems, to get that last bit of air out. 

In this case I have no fluid making it through at all, which is bizarre for me, but in reality most of the time when i'm doing something like this what you're talking about is of key interest.  at least for a "why not", i'll go lash the lever back for an overnight.  I did, at least in my mind, seem to think there was a slightly different feel/sound when i released the bleed valve after holding the lever in for many seconds, and certainly notice over the years that when i get impatient and pump the lever too fast its different than when its slow and with a slight hold before opening the valve, as you'd well know.

And for fun Phil, I checked for water on an old C140 a couple decades ago, only to learn the hard way that the sump drain on an unmodified 140 is mid tank, so as a tail dragger, I wasn't sumping anything but the fuel above the water that was hiding down there at the aft/bottom.... Ran great till about 800ft AGL, then I had a nice unplanned landing at my in-laws fallow field. 

[gstallons]

Just to be certain , you are using DOT 4 fluid ? This is not going to affect anything , I just want to be sure.

 Back in the early 80s when Ford first started using hydraulic clutches on the F series truck you could spend the day bleeding the system .  AND there was no method to rely on to get the job done. .

Edited Monday at 11:50 PM by gstallons

[audiomick]

2 hours ago, Lucky Phil said:

So the question is does a quantity of dissolved air or air molecules suspended in a given amount of fluid in a sealed system have less affect on the compressibility of the fluid than the same amount of air in a formed bubble within the same system.

I'm not a physicist, but I'm incredibly intelligent, so...

Firstly, the air in the brake system is, as far as I understand it, dissovled under pressure, not suspended. Therefore, the system is filled with liquid with practically no bubbles.

The point is, liquid is incompressible. Bubbles (gas) are compressible.

Gas dissolves in the liquid surrounding better under pressure.

So holding the lever under pressure overnight can lead to the air bubbles dissolving in the fluid. Because the bubbles are dissolved, you will have a better function the next day. The next step (confirmed to me by someone who has done professional workshops on hydraulic brake systems and so on) would not be to think "it's all ok now", but rather to seize the opportunity to flush the system with fresh brake fluid to get rid of the dissolved air.

The air was dissolved under pressure, and when the pressure is not a constant, the air will come out of solution and form bubbles again.

[docc]

Not to burst anybody's bubble (heh ), but I have tied back the front brake lever on a failed bleed that I could not get any pressure whatsoever and the lever feel (pressure) came back overnight.  At the time I thought the rationale was that the master cylinder, in the "activated" position, allowed air to rise into the reservoir, Do doubt, this has only worked for me with the master cylinder fluid supply line angled above the cylinder with the reservoir higher.