bleeding brakes 46 Lincoln

[GasWorksGarage]

So I replaced the master cylinder. I bench bled it before install. I have a good stream at the point where the line attaches to the MC. but, I cant get the air out of the lines. I am using a mityvac. Any clues?

[Bruce Lancaster]

This is quite likely due to overall low car with master cylinder way down...I would try getting each end of the car in turn way up, by jacking or parking on the steepest driveway you can find.

[Bob C]

Might try some speed bleeders. http://www.speedbleeder.com/

Bob

[rotorwrench]

The bleeder nipples are sometimes too loose in the threads and just keep sucking air. Speed bleeders help too but I just put some teflon tape on the bleeder nipple threads before I install them into the wheel cylinder. This stops the air from leaking around the threads.

[paul2748]

The teflon tape thing may work for rotorwrench, but I am very leery of putting teflon tape around brake parts.

Originally Posted by rotorwrench

The bleeder nipples are sometimes too loose in the threads and just keep sucking air. Speed bleeders help too but I just put some teflon tape on the bleeder nipple threads before I install them into the wheel cylinder. This stops the air from leaking around the threads.

[rotorwrench]

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If a person takes the nipple out of the housing, they have to be sure to remove any residue of the tape but most folks only take them out when performing an overhaul of the cylinder. What is surprising, is how loose these things are in the newer off shore manufactured products. Some of them actually wiggle in the threaded bore after you loosen them to bleed. The tooling used is not accurate at all. Back in the day the bleeder nipples took some force to get them to turn even after the needle was broken free of the seat so there was no need for any sealing material.

We have to live with what is available now. If you look at the speed bleeders, they have some type of material on the threads too so that's just what the world has come to these days.

[Panheadguy]

I'm with rotor on this. I have a vacuum bleeder and a mityvac. Both suck air and give a false indication by showing bubbles unless the threads are sealed. Just keep the tape away from the bleed hole and you will have no problems.

[SofaKing]

Originally Posted by rotorwrench

The bleeder nipples are sometimes too loose in the threads and just keep sucking air. Speed bleeders help too but I just put some teflon tape on the bleeder nipple threads before I install them into the wheel cylinder. This stops the air from leaking around the threads.

This has always been my experience when trying to pull brake fluid through the lines with vacuum. I never tried teflon tape, I made a 20$ pressure bleeder. I can send photos if you like. The parts are available anywhere. I have used it on many makes of cars, works well.

[al pa.]

I havent tried it,but read that a very thick grease around the bleeder would stop air leaks.(not to remove bleeder,or grease threads)

[V8 Bob]

The best method is pressure bleeding each wheel, using a correct bladder-type brake bleeder, while slowly full stroking the master. One man operation.
Second is simply pedal bleeding one wheel at a time while slowly full stroking the master. Speed bleeders also make this a one man operation; otherwise two will be required.
When some pressure can be built, check for leaks by applying very high pedal force. Make sure the system is leak/weep free before spending any further time bleeding. Use isopropyl or denatured alcohol for cleaning all fittings, unions, etc, and for general clean up on the car and hands.
Grease and Teflon tape really should not be used on any parts in contact with brake fluid. :-)

[JWL]

I agree. Pressure bleeding or train the wife to pump the pedal.

[JSeery]

Originally Posted by JWL

"train the wife to pump the pedal"

This CAN be done with enough effort! I have accomplished this feat.

[Talkwrench]

Its a single circuit [I take it] , You don't need to bench bleed and don't push the pedal all the way to the floor, sure way to bugger up a single circuit M/C . And yes speed bleeders are your friend, great if your on your own. Your next of kin is a big plus too.

[V8 Bob]

Originally Posted by Talkwrench

and don't push the pedal all the way to the floor, sure way to bugger up a single circuit M/C .

Curious why you think that. If damage was possible, there would be an adjustable pedal stop to prevent full stroking, something I've never seen or have any knowledge about. Now, I'll admit I haven't messed with a single system master for well over 40 years, but when I did, I never damaged a master by fully stroking during bleeding.

[Talkwrench]

I'll see if I can find the instruction's for the USA made m/c there was warning in there about full stroking and damaging internals, might still have a box. From memory it might of even said about placing a brick or wood block behind the pedal to make sure. Leave it with me see if I can find it Bob.

[Talkwrench]

Found the old M/C but I didn't keep the instructions [warning] . Maybe someone else has instructions they could post? Should be with the USA made one , I bought through Macs' .

[rotorwrench]

There is a possibility that damage could be done when full stroking an empty master cylinder on some applications. Some of the instruction sheets that come with new or overhauled components are general in nature and may or may not apply to all designs. Personally, I don't start applying any movement on master cylinders till after I've serviced it with brake fluid. Once it starts building pressure in the system at application of pedal, you have all the stops you need if it is functioning correctly.

[supereal]

I think the "MityVac" brake bleeding was invented by the fluid makers because it take lots of pumping of the gadget to get any sort of a "pedal", and fluid quantities by the quart. The master cylinder on old Fords is located below the level of the wheel cylinders making "push and hold" bleeding time and fluid loss extensive. A pressure bleeder does it in minutes. Be sure the linkage to the master cylinder allows the piston to retract enough to permit the hole from the reservoir to allow fluid to replace the amount lost by bleeding.

[rotorwrench]

I've used a Mityvac for years but I rigged up a larger container to catch the fluid. As long as the system has been completely flushed out and cleared with compressed air, the fluid comes out clean and can be reused.

Now I know that some folks won't condone this but I really don't care. Use it or throw it away. It's the individuals choice. Same as using teflon tape to seal a bleeder nipple. I've never had fluid sucked back in the system before shutting the valve off so it's of no concern to me there either. To each their own.

I've used pressure bleeders too but thoroughly flushing and evacuating the system is just as important there too. Whatever you push into the system has a tendency to stay there. How clean is your pressure bleeder apparatus?

[richard crow]

get a clean jar put a tight fitting hose over the nipple on the bleeder screw. put other end of hose in jar put enought brake fluid in gar to cover bottom of hose . open bleeder screw pump pedal look at jar when you see no air bubbles close bleeder now if you are using dot 5 you can pour the fluid back in if clean dot 5 is expensive. that,s how i do it when i have no one to pump pedal