Proper brake bleeding order?
- ruckman101
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Proper brake bleeding order?
Have a new master cylinder in, going to change all the brake hoses today, and so someone please correct me if I'm wrong, but when bleeding a brake system, I start at the wheel furthest from the master cylinder and work my way to the closest wheel to the master cylinder, yes?
And one other note, when disconnecting the two brake lines from the old master cylinder, the brake fluid in the chamber towards the rear of the car was under pressure, spraying when released, unlike the front chamber. Is this an indication of constricted hoses, or is it that the small port that feeds and relieves the chamber of fluid is blocked by crud, again, probably from deteriorating hoses? The reservoir on top of the master cylinder was certainly full of black crud.
thanks, neal
And one other note, when disconnecting the two brake lines from the old master cylinder, the brake fluid in the chamber towards the rear of the car was under pressure, spraying when released, unlike the front chamber. Is this an indication of constricted hoses, or is it that the small port that feeds and relieves the chamber of fluid is blocked by crud, again, probably from deteriorating hoses? The reservoir on top of the master cylinder was certainly full of black crud.
thanks, neal
The slipper has no teeth.
- Amskeptic
- IAC "Help Desk"
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Re: Proper brake bleeding order?
ruckman101 wrote: when bleeding a brake system, start at the wheel furthest from the master cylinder and work to the closest wheel to the master, yes?
Yes, but note that it does not matter if you start at the front or the rear with dual circuit brakes so long as you do the furthest for the circuit you are working on and work your way in.
Either or both . . . could cause the above symptoms.ruckman101 wrote: brake fluid in the chamber towards the rear of the car was under pressure
Is this an indication of constricted hoses, or is it that the small port that feeds and relieves the chamber of fluid is blocked by crud?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
- ruckman101
- Lord God King Bwana
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Re: Proper brake bleeding order?
Thanks. Front hoses looked ok. However the new Mehle replacements did not have the extra rubber insulator that fits into the clips just outside the drum. Sliced off the old ones and put them on the new hoses.
neal
neal
The slipper has no teeth.
- ruckman101
- Lord God King Bwana
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Re: Proper brake bleeding order?
Sigh. The plug I used to block the unneeded third brake line on the new master cylinder isn't plugging. It seeps. Discouraging to have put all this effort in and the brakes are no better than when I started. I thought about teflon tape, as the plug is for a plumbing application, but I wrapped the plug in teflon tape before installing it and soaked it in used brake fluid and the tape softened and thinned after ten minutes or so. There must be actual plugs designed for this application. FLAPS?
neal
neal
The slipper has no teeth.
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- Getting Hooked!
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Re: Proper brake bleeding order?
You used the proper metric tapered pipe plug (M10x1)? If you tried to use a 1/8" NPT plug, the threads in the M/C or residual pressure valve
are likely damaged, but probably fixable with a tap. It's very doubtful if any FLAPS would have metric plugs, but Googling "metric pipe
plug" turns up several on-line sources. Other possibilities: a (shortened) M10x1 bolt with sealing washer; an old brake line end
cut off short, crimped and filled with solder; an old brake lite switch.
I don't know if it actually matters, but VW/Bentley actually went to the trouble to specify a brake bleeding sequence of R. front > L. front >
R. rear > L. rear.
are likely damaged, but probably fixable with a tap. It's very doubtful if any FLAPS would have metric plugs, but Googling "metric pipe
plug" turns up several on-line sources. Other possibilities: a (shortened) M10x1 bolt with sealing washer; an old brake line end
cut off short, crimped and filled with solder; an old brake lite switch.
I don't know if it actually matters, but VW/Bentley actually went to the trouble to specify a brake bleeding sequence of R. front > L. front >
R. rear > L. rear.
- hambone
- Post-Industrial Non-Secular Mennonite
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Re: Proper brake bleeding order?
Great stuff! How the hell do you know that off the top o' your head?
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it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
- ruckman101
- Lord God King Bwana
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Re: Proper brake bleeding order?
Tightened way beyond spec, but the brass plug from the FLAPS seems to have done the trick. Whew.
neal
neal
The slipper has no teeth.
- Amskeptic
- IAC "Help Desk"
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Re: Proper brake bleeding order?
The benefit of doing the front circuit first, is that it fills/pressurizes the end of the master cylinder, giving you better "push" for the longer path of the rear circuit.kreemoweet wrote:
I don't know if it actually matters, but VW/Bentley actually went to the trouble to specify a brake bleeding sequence of R. front > L. front >
R. rear > L. rear.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
- ruckman101
- Lord God King Bwana
- Location: Up next to a volcano.
- Contact:
- Status: Offline
Re: Proper brake bleeding order?
Amskeptic wrote:The benefit of doing the front circuit first, is that it fills/pressurizes the end of the master cylinder, giving you better "push" for the longer path of the rear circuit.kreemoweet wrote:
I don't know if it actually matters, but VW/Bentley actually went to the trouble to specify a brake bleeding sequence of R. front > L. front >
R. rear > L. rear.
Colin
Perfect sense. Even more so for acclimatizing a new master cylinder to the system, along with four new brake hoses. Bertha Bus did well on her first run into town yesterday. Even under a moment of panic and heavy application. Still, it itches at me that I should do one final bleed of the system. My experiences with the recently purchased vacuum brake bleeding tool at this point are overwhelmingly disappointing.
neal
neal
The slipper has no teeth.
- Amskeptic
- IAC "Help Desk"
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Re: Proper brake bleeding order?
They are by their very design wrong. Do NOT apply a vacuum through a pressure system. A pressure bleeder with a very modest 3-5 psi from the reservoir on down is perfect.ruckman101 wrote:My experiences with the recently purchased vacuum brake bleeding tool at this point are overwhelmingly disappointing.
neal
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
- hambone
- Post-Industrial Non-Secular Mennonite
- Location: Portland, Ore.
- Status: Offline
Re: Proper brake bleeding order?
6 psi pressure bleeder on the Squareback, and the brakes were fine on that fateful day without windows or latches. It's a handy way to do it alone.
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
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- Old School!
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Re: Proper brake bleeding order?
Have never had an issue using a Mighty vac when bleeding brake/s on a VW.
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's
- sgkent
- Addicted!
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Re: Proper brake bleeding order?
Mighty vacs have never done it for me. Put your spouse or a friend in the driver's seat and have them work the pedal. If you don't know how ask. A pressure bleeder works good too for one person bleeding and they aren't all that expensive. A really good Mighty Vac can be ruined by brake fluid.
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Merlin The Wrench
Merlin The Wrench
- Bleyseng
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Re: Proper brake bleeding order?
Yep been there done that! I prefer the tried and true helper pushing the brake petal while I drain each brake cylinder. "Push......Hold.....Push....."sgkent wrote: ↑Wed Jul 19, 2017 9:17 pmMighty vacs have never done it for me. Put your spouse or a friend in the driver's seat and have them work the pedal. If you don't know how ask. A pressure bleeder works good too for one person bleeding and they aren't all that expensive. A really good Mighty Vac can be ruined by brake fluid.
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
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77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/
- asiab3
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Re: Proper brake bleeding order?
Vacuum bleeding technique can be rendered useless by loosening the bleeder screw too much, to the point where the vacuum apparatus starts to suck air from around the bleeder threads. Many people do this and have miserable results. I've seen it done poorly, and done well, and I absolutely think there is more skill involved with that technique.
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.
145k miles with me.
322k miles on Earth.