Brake Bleeding???

[fordf350man]

Yes, someone in the know told me that also about the newer cars and trucks. Pushing the piston back pushes all that old rusty fluid back up in the complicated abs valve system and can cause it to fail. After I was told that, I started to also do it on these older trucks. It's doesn't hurt the master, but our systems can also do without all that rust being pushed back up in the system, and also if you keep the master topped off, it will overflow and make a mess unless you release the bleeder and let the excess fluid come out there. By the time you do that, and then bleed them a little bit from the master, you should have mostly new fluid in the system, getting rid of that old stuff.

you should never add brake fluid unless you are flushing the system or refilling because of a leak, the brake system is a sealed system and any time it is open to the air it can absorb moisture and contaminants witch will cause issues, there is no need to open the bleeders to push the pistons back in, if there is crud in the system it needs a flush, a properly maintained brake fluid system should not have any contaminates, you get the rust build up because people open the master cylinder to add fluid and at that point it absorbs the moisture witch causes the the rust to form inside the system, the fluid level is actually the wear indicator for the brake pads and shoes, when the level gets down to the min mark that means the pads are getting low and its time to change them, like you said when people add fluid and then press in the piston it overflows and that's because the system was over filled, if it isn't overfilled and you change the pads when the pistons are pushed back in for new pads then the fluid level will be at the max mark, another thing people to is push the little boot back in on the cap for the master cylinder and your suppose to leave that popped out, with that popped out it makes a smaller space inside the master cylinder to be filled with air so less moisture can be absorbed into the fluid, as long as the system stays sealed there is no need to flush it every year, i would do every 50,000 miles myself, GM recommends at 100,000 miles for a brake fluid flush so do other manufacturers

pumping the pedal on while bleeding brakes isn't a bad thing, has never failed me or taken long, it allows pressure to be built up in the system to force air out, just like a pressure bleeder, doing that helps to eliminate air in the hard areas like ABS modules and valves and things of that sort, i now have a pressure bleeder that applies the pressure to the master cylinder and then its a one man job to go to the bleeders and open them, but having someone pump the pedal is the same thing, build pressure to force air out, not trying to start any battles here just my two cents i know there are many different ways and theories to do this, as long as it gets done who cares

 

[G. Mann]

I cheat.

I use a cheap electric fuel pump to bleed brakes. It makes it a one man job. First, I use the pump to evacuate the old, tired, dirty brake fluid. Hook the pump up to the bleed screw, use cheap clear poly hose [hardware store has it in bulk, pick the size that fits the nipple on bleed screw]. Put another length of clear hose on the exit side of the pump into a container and pump away. When that wheel is done, close that bleed screw and move to next longest, till all wheel cylinders and the master resivour is empty [I like to add a little clean fluid to flush the lines if the system was really dirty.

Then, reverse the pump. Put the suction hose in a fresh bottle of brake fluid, hook the pump exit hose to the bleed screw, and pump clean fluid from the bottom up to the master cylinder. Air wants to move UP, not down, so as you pump from the lowest point it moves the air out of the system. Watch the master cylinder. When you have about 1/2 inch of fluid from the right rear, close that bleed screw and move to left rear, repeat at each wheel, keep an eye on overfilling the master, you don't really have to pump much fluid from each wheel, just enough to be sure you are pumping fluid, not air.

When you get all 4 wheels pumped and bleed screws closed before you move to the next wheel, top off the master and try the brakes. It works well for me, perhaps it will for you. I used low voltage wire [outside landscape lighting] to make an "extension cord" for the electric fuel pump, some barb fittings to fit the poly tubing, and poly tubing, all from ACE hardware.. I only use the poly tubing once and discard it. [Ok.. recycle it.. for you tree huggers].

Average time to bleed brakes for me using this system is about 15 minutes and I don't have to wait till I get someone to "pump the brakes". Got the electric pump from a pick and pull lot for couple bucks and been using it for 12 years to just pump brake fluid.

 

[fordf350man]

I cheat.

I use a cheap electric fuel pump to bleed brakes. It makes it a one man job. First, I use the pump to evacuate the old, tired, dirty brake fluid. Hook the pump up to the bleed screw, use cheap clear poly hose [hardware store has it in bulk, pick the size that fits the nipple on bleed screw]. Put another length of clear hose on the exit side of the pump into a container and pump away. When that wheel is done, close that bleed screw and move to next longest, till all wheel cylinders and the master resivour is empty [I like to add a little clean fluid to flush the lines if the system was really dirty.

Then, reverse the pump. Put the suction hose in a fresh bottle of brake fluid, hook the pump exit hose to the bleed screw, and pump clean fluid from the bottom up to the master cylinder. Air wants to move UP, not down, so as you pump from the lowest point it moves the air out of the system. Watch the master cylinder. When you have about 1/2 inch of fluid from the right rear, close that bleed screw and move to left rear, repeat at each wheel, keep an eye on overfilling the master, you don't really have to pump much fluid from each wheel, just enough to be sure you are pumping fluid, not air.

When you get all 4 wheels pumped and bleed screws closed before you move to the next wheel, top off the master and try the brakes. It works well for me, perhaps it will for you. I used low voltage wire [outside landscape lighting] to make an "extension cord" for the electric fuel pump, some barb fittings to fit the poly tubing, and poly tubing, all from ACE hardware.. I only use the poly tubing once and discard it. [Ok.. recycle it.. for you tree huggers].

Average time to bleed brakes for me using this system is about 15 minutes and I don't have to wait till I get someone to "pump the brakes". Got the electric pump from a pick and pull lot for couple bucks and been using it for 12 years to just pump brake fluid.

this isn't cheating this is genius, you just made a reverse bleeder for very low cost, those things cost allot of money to buy, great way to use your mind i just might borrow your idea

 

[LCAM-01XA]

another thing people to is push the little boot back in on the cap for the master cylinder and your suppose to leave that popped out, with that popped out it makes a smaller space inside the master cylinder to be filled with air so less moisture can be absorbed into the fluid, as long as the system stays sealed there is no need to flush it every year, i would do every 50,000 miles myself, GM recommends at 100,000 miles for a brake fluid flush so do other manufacturers

Actually no, that boot is supposed to sit flat when the fluid is at its full mark, it's a rubber diaphragm that 's supposed to pop-out by itself as the fluid level goes down due to pads wearing. It can only stretch so much, and "popping it out" when the master is full means as fluid level is going down there's a lot of pulling action on the rubber boot. Also opening the cap is needed with older masters, you have the 2-piece design with the plastic tank and the float sensor to boot, but '86 and older trucks run 1-piece all-metal master that leaves you no way of checking fluid level other than opening the cap. And checking the fluid level is a good practice if the truck sits a lot, sometimes things let go without a warning, and simply jumping in and driving off without taking a few minuets to do a pre-trip could prove disastrous.

 

[fordf350man]

Actually no, that boot is supposed to sit flat when the fluid is at its full mark, it's a rubber diaphragm that 's supposed to pop-out by itself as the fluid level goes down due to pads wearing. It can only stretch so much, and "popping it out" when the master is full means as fluid level is going down there's a lot of pulling action on the rubber boot. Also opening the cap is needed with older masters, you have the 2-piece design with the plastic tank and the float sensor to boot, but '86 and older trucks run 1-piece all-metal master that leaves you no way of checking fluid level other than opening the cap. And checking the fluid level is a good practice if the truck sits a lot, sometimes things let go without a warning, and simply jumping in and driving off without taking a few minuets to do a pre-trip could prove disastrous.

well i am not from the old days as most of you on here are, i am young but i am going off what i learned from my instructors in college that are the old timers and from my time working as a technician, that is what i learned for the diaphragm and i never had a problem with them stretching to far, but im not going to say your wrong or im right, just what i was taught, i can definitely see if there is no visible way to check the fluid level other than taking the cap off, but then to now is still the same, it is not good to open the system as the fluid will absorb moisture, many things were done back in the day and there is a reason that today they have done away with those ways, if there is no leaking then the system is full, no getting around that, so still if you couldn't see the level if there is no leak it is full, same as a coolant system, only need to fill it if there is a leak, they are sealed, yes over time it needs to be replaced but they should never need to be filled unless there is a leak or flushing

 

[LCAM-01XA]

well i am not from the old days as most of you on here are

Lol, you'd be surprised how many of the folks here actually drive vehicles older than they are - there is just something about simplicity and ease of repairs and modifications, with a newer vehicle none of those is present and your creativity and fab skills and are easily kicked to the curb by some random GEM burried who knows where...

Still I agree keeping the system sealed is a good thing, but at the same rate it is practically impossible to notice a leak from just a quick walk around the truck - especially if like I said truck has been sitting for a while, one good rain or strong dusty wind after the leak occurred and before your inspection and all traces are washed away or covered up. With a plastic see-thru reservoir you can have your cake and eat it too, with a one-piece metal one I'll keep opening it regularly and then flushing the fluid yearly, it's really no big deal for me. By the way not everything done now is improvement over the old days, prime example would be the front axle of your own truck - now what exactly was wrong with the '70s spring setup that they had to flip them around and put the shackles on the front?

Regarding the boot, take a look at its shape when it's popped out, there is always some sort of irregularity in it. In contrast, when it's retracted its shape is always darn near perfect. To me this is a good indication of what its intended position is... Not to mention that if you fill an old-style master up then pop the boot out as you're installing the cap you will push a whole bunch of fluid out of the master reservoirs. And with a newer plastic reservoir the boot may end up pushing down on the float sensor.

 

[fordf350man]

Still I agree keeping the system sealed is a good thing, but at the same rate it is practically impossible to notice a leak from just a quick walk around the truck - especially if like I said truck has been sitting for a while, one good rain or strong dusty wind after the leak occurred and before your inspection and all traces are washed away or covered up. With a plastic see-thru reservoir you can have your cake and eat it too, with a one-piece metal one I'll keep opening it regularly and then flushing the fluid yearly, it's really no big deal for me. By the way not everything done now is improvement over the old days, prime example would be the front axle of your own truck - now what exactly was wrong with the '70s spring setup that they had to flip them around and put the shackles on the front?

lol good point with the axles but im only 25 and just turned that in April so my truck is still old to what i have been wrenching on, trucks i have been ride smoother than most cars do, and super duties that i work on are all coil spring in the front, my truck in 1997 was new and i was only 8 to 9 years old lol, hope i don't make anyone feel old,