Flare brake lines?

On 3/17/2015 11:05 PM, snipped-for-privacy@snyder.on.ca wrote: ...


Which is actually what started this: On 3/16/2015 8:54 PM, Jim Wilkins wrote:> Next question: > How do you seal the air leak along the bleeder threads when vacuum > bleeding? I didn't want to squirt on something incompatible that might > get back into the cylinder.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've replaced brake lines and/or wheel cylinders on every vehicle I've owned, since I keep them in good condition a long time. The thread leakage had never been an issue for me until I had to diagnose and cure a spongy pedal, and couldn't distinguish leakage at the bleeder from air in the lines.
The advice I was hoping for was a recommendation of a compatible or insoluble heavy grease to put on the bleeder threads. The only "brake grease" I have is for the caliper slides and rear self-adjuster, and its strength is a high temperature tolerance to keep it off the friction surfaces rather than compatibility with the fluid and rubber cups. http://en.wikipedia.org/wiki/Dropping_point
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/18/2015 8:00 AM, Jim Wilkins wrote: ...

I have seen a YouTube video of bleeding with vacuum where they put something on the bleeder threads to seal them. Sorry that I can't be more specific, as there is a gazillion brake bleeding videos.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wednesday, March 18, 2015 at 5:20:09 AM UTC-7, Bob Engelhardt wrote:

I've used HandiTak for that (and have heard that plumber's teflon tape also works, but cannot confirm).
<(Amazon.com product link shortened)>
It deteriorates incontact with brake fluid (I was sloppy), but it seals well enough to do a vacuum bleed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Describe what you call a vacuum bleed please - there are so many possibilities.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


For me it means connecting a Mityvac or HF bleeding kit to the wheel cylinder bleeder, pumping to 25", opening the bleeder and watching the fluid and maybe air flow out. Normally I stop when the fluid turns lighter, then torque the bleeder to spec, blow out the remaining water-absorbing fluid, replace the rubber cap and top off the master cylinder.
Now that I'm retired and not driving 50 miles in stop-and-go freeway traffic every day the fluid doesn't heat up enough to darken. -jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 19 Mar 2015 18:00:47 -0400, "Jim Wilkins"

And there is NO WAY air or anything else is going to get in to the system due to leakage around the bleeder screw threads doing it that way. What's the big issue about the threads not sealing 100%??? When the screw is closed the threads don't have to seal anything because the tapered seat does the sealing..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


Right. As I said, the problem appeared only when I was trying to refill a spliced line and I couldn't tell if the bubbles meant I needed to keep flushing my limited supply of genuine Honda brake fluid through. That's when I woke up the neighbor and asked for help pushing the pedal, which blew out the residual air in a different line that was making the pedal very soft.
Today I asked about bleeding at the dealership while stocking up on more fluid. They always have someone to pump the pedal. They also gave me a trade-in value. At least the 15-year-old car is worth something to me. Maybe I scared it into behaving for a while. -jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thursday, March 19, 2015 at 4:27:20 PM UTC-7, Clare wrote:

>> Describe what you call a vacuum bleed please - there are so many

The two-person bleed procedure pressurizes the brake lines and blows crud out of them. A one-person vacuum bleed is also possible, using atmospheric pressure at the master cylinder and pulling a vacuum at the bleed port with a "Mityvac" brand hand pump. The problem there, is that the (loose) bleed valve can fill the little waste bottle with brake fluid from the lines, or with air from the lines, or with air that leaks past the threads of the valve. Even if air doesn't get into the brake lines, there's no way to know when the bleed is good enough, unless you smear some sealant around the valve threads.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I've never seen a professional mechanic put sealer on a bleeder thread.. I've never put sealer on a bleader screw.. I have a little battery operated electric vacuum bleeder. I have a mighti-vac. I virtually never use them for bleeding brakes. So much easier to gravity/pump bleed. The pressure bleeder was the cat's meow back when I was at the dealership. Clamp the fitting on the master, dial up the pressure on the tank, open the bleeder 'till the bubbles stop, Close the screw. repeat on the other 3 lines. It wasn't foolproof. Couldn't pressure bleed a '60's Vauxhaul with twin leading shoe brakes while sitting level. Reverse bleeding is the "secret weapon" in cases like that. Standing the car on it's nose overnight works too. Don't want to have to do that too often!!. (line went into the "top" cyl. with a jumper line from the top cyl to the bottom cyl, and the bleeder on the bottom of the bottom cyl, of all places!!!)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 18 Mar 2015 08:00:29 -0400
<snip>

I would and have used "SIL-GLYDE Lubricating Compound" for stuff like that. Been using it to protect/seal the reservoir/pumps area on my Magna motorcycle for many years now. The tube I have is very old, given to me by a professional mechanic. He was giving me advice on how to rebuild the front disc brakes on my truck. See:
http://www.agscompany.com/images/stories/lubricants/automotive/sil-glyde_lubricating_-_tds.pdf
(Amazon.com product link shortened)
Haven't noticed any thing odd/weird going on when I change the fluid in the reservoirs on the cycle yearly.
--
Leon Fisk
Grand Rapids MI/Zone 5b
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Yep, that's the right direction. Thanks.
Here is some discussion for and against using it on disk brake piston seals: http://forums.pelicanparts.com/porsche-911-technical-forum/335758-caliper-rebuild-grease.html
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 18 Mar 2015 08:59:06 -0400

They make/sell it with several different names. I don't know if it is all the same or not. That article doesn't really say which version the original poster was using but I got the feeling it was the stuff for stopping squeals. Lots of other useful suggestions there though. For some info on the different "Glydes" see:
http://agscompany.com/product-category/lubricants/
They seem to like that "Glyde" name :)
--
Leon Fisk
Grand Rapids MI/Zone 5b
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

These are somewhat helpful: http://honda-tech.com/honda-civic-del-sol-1992-2000-1/oem-honda-caliper-seal-rebuild-kit-grease-what-1948126/ http://www.nippon-grease.co.jp/en/products/grease/g02.html
My shop manual is similar. The text says to "Coat the piston, piston seals and caliper bore with clean brake fluid", but doesn't mention the piston seal grease.
I suspect that a grease meant to go on the piston seals won't cause a problem if a bit of it leaks in from the bleeder screw, although they must have a reason for specifying a different grease on external parts.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 17 Mar 2015 23:05:53 -0400, snipped-for-privacy@snyder.on.ca wrote:

Most of which have disc brakes. That cuts way down on the mess left from a leak.

It's messy, and fluid can leak into the brake area beneath the cylinder on older cars and trucks. Not much (more of a seepage) and not on the shoes, but some. I prefer a cleaner job.

The low pressure used would make it seem less troublesome.

Verily!
I have 53k miles on my '07 Tundra now, and need to check/replace pads. Do you have any specific suggestions or tips toward brake jobs for them? You've been in the loop considerably more recently than I. There is zero pedal undulation, so I doubt I need to turn the rotors, unless that's a recommended procedure. I haven't yet looked into it.
I know the brakes have been wearing because I've needed to adjust the emergency brake cable twice now. (step on/step off style) It's a 4-wheel disc setup, which I adore. It was the brake system alone which killed my enthusiasm for the Tacoma and sold me on the Tundra. The Tacoma took both feet and all I had to make it stand on its nose, and it still wouldn't. The Tundra danced to a stop quickly and easily, with little pedal pressure, nearly ripping up the macadam in the process. ;)
--
Always bear in mind that your own resolution to
succeed is more important than any one thing.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Larry Jaques wrote:

Only thing I have done was to pull the bleeder and dab some silicone grease on the threads. I suppose you could crack the bleeder and coat the thread area with common RTV or even silly putty. It would stop the leak around the threads, but if you have drum brakes you might still get leaks past the cups.
I use a pressure bleeder for the vehicles that won't reliably gravity bleed.
--
Steve W.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 16 Mar 2015 20:54:00 -0400, "Jim Wilkins"

I don't vacuum bleed mine. I get someone to help me. When working in the trade, that's what apprentices were for - I'd pump the pedal and HE would get sprayed!!!. I've actually found that single handedly I can usually bleed most brakes pretty well by JUST cracking the bleader and forcing the last air out past the threads.Releasing the pedal slowly doesn'r draw in enough air to cause a problem. Disk brakes bleed themselves.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I can ask the retired neighbors who call on me when their stuff breaks, IF they aren't asleep or away at the VA.
In the past a pipe or broomstick resting on the brake pedal and pulling against the steering wheel with bungee cords has been enough to pump the old discolored fluid out of the wheel cylinders. Vacuum bleeding does that pretty well too, when I know that the pedal is solid and the bubbles I see in the tube are only from the air leak at the threads.
In this case the long line to the rear had mostly drained so I used vacuum to refill it quickly.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 16 Mar 2015 19:23:11 -0400, snipped-for-privacy@snyder.on.ca wrote:

Newp. Iffen you didn't buy them from the dealer, you bought a used car. Like gravity, it's the LAW!

Well, if you're not smarter than the cheap Chiwanese part, then... ;)

I had a fun half hour this morning. Y'know that new battery I bought a couple weeks ago? The old one decided it would die on me this morning on the way to a job. I lucked out, listening to my intuition those weeks ago, so I was back on the road in 20-some odd minutes.
--
However beautiful the strategy, you should occasionally look at the results.
-- Sir Winston Churchill
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 16 Mar 2015 20:58:26 -0700, Larry Jaques

I bought the Taurus from the dealer that sold it new to the first owner - does that count????

What? You didn't pop the battery open and repair it??? (BG)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.