Dan's Brake Thread

[bordin34]

I bought new bearings and rotors and installed them this week and bled the front. While bleeding the drivers side I noticed the grease boot on the upper ball joint was torn, would this pose a major problem, like the joint suddenly popping apart.

[The70RT]

I bought new bearings and rotors and installed them this week and bled the front. While bleeding the drivers side I noticed the grease boot on the upper ball joint was torn, would this pose a major problem, like the joint suddenly popping apart.

As long as your ball joint is tight your ok. You may have to grease it more often because that holds the grease in and the dirt out. If they are original you are probably gonna be replacing them eventually. Then your taking all the brake work back off. Then it is do you replace the lowers?...then pretty soon your doing the complete front end like you will eventually if you plan on keeping the car for a long time 

[bordin34]

I bled my brakes and tested the pedal, it was really soft. So I began thinking, I remembered that while bench bleeding the Master, when I applied pressure fluid would shoot up out of the front reservoir, the one that feeds the rear brakes. Does this mean my Master is bad and not putting any pressure to the rear?

[The70RT]

I bled my brakes and tested the pedal, it was really soft. So I began thinking, I remembered that while bench bleeding the Master, when I applied pressure fluid would shoot up out of the front reservoir, the one that feeds the rear brakes. Does this mean my Master is bad and not putting any pressure to the rear?

I doubt it. I would make sure you bleed the whole system good. New brake fluid and a flushing of the old would be a good idea anyway.

[bordin34]

My dad and I bled the front and I gravity bled the rear. I have all new fluid in the system. I was just thinking that instead of it maintaining pressure on the plug when pushing by hand it was effectively bypassing the pressure somehow  and turning around then squirting back up. I can't really describe it so I tried drawing my thoughts.

[Steve P.]

Even when you have done a perfect brake job on all 4 corners, you will have a spongy feel at the pedal until you burn in the brakes. Make sure your rear shoes are adjusted up and then check your pedal. If you have plenty of pedal take it for a ride and do some test stops before getting very far. I do a series of short 20mph and stop. Then when I know I have a good solid brake system I take it out to where I can do some 35-40mph long gradual stops to burn in all the new brake material.

If you do all that and still think you have a sponge pedal I would start bleeding the system starting at the farthest wheel, (RR), then LR then FR and lastly FL.

With all of this and knowing that all parts are installed right and are in good shape you should be set.

[bordin34]

With the engine off, I just compared the brakes to those on my dad's '97 Mustang and they seemed to pump up just as fast and firm. I think I will still re-bleed the rears just for good measure.

[bordin34]

I am gravity bleeding the rears again and when I filled the reservoir I noticed that the fluid in there was noticeably dirty I don't know how it could happen. I blew out all the lines and put fresh fluid in so I don't know how it could have gotten dirty. All that I am really concerned about now is the fluid squirting up out of the reservoir.

[resq302]

Just because you blew out the lines doesnt guarantee that you got all of the sludge out that might have been sticking on the walls of the tubes.  Might have to run the car for a bit and then power bleed the lines and clean them out again.  I've never really had an issue like this since our cars pretty much always had the brake lines replaced with stainless lines and then just replaced with new fluid.

[green69rt]

I'm resurrecting this thread for one question.  I've always heard that when replacing bearings on a car (front wheel bearings)  that the hubs are NOT packed full of grease.  Bearings are greased correctly, and if some extra grease ends up inside the hub during assembly then that's OK.  But do not pack the hub full.  Which is correct.

[birdsandbees]

FSM says to fill hub even with bearing cups and hand (or pressure) pack bearings. As I did and show in my thread. I always did what you're saying ... until I read the FSM yesterday!   Mind you thinking back to the diagram showing a cutaway hub and what I think was their depicted grease fill I may have overdone it a bit!

EDIT: just did a little googling and I see all the arguing about it for both ways. This guy laid it out pretty good

First, what is grease, and why are its properties important for particular applications? Grease is roughly 90% oil, 5% thickener, and 5% additive packages (EP, R&O, etc). The thickener in grease acts the same as a sponge. Squeeze it, and the oil releases. This is the mechanical release of the lubricating oil from the thickener. Very little grease in or around the bearing is subjected to mechanical working. The other release method is temperature rise, of which all of the grease in most housings is subjected to. It is the release of the lubricating oil and how it travels in the housing that must be evaluated.

After the bearing is packed full, installed, and run a bit the bulk of the grease is channeled out of the bearing. In effect, the bearing will purge what it does not need. This is important since too much lubricant can cause overheating. Think of it like walking on the beach. Is it easier to walk in a thin film of water or water up to your hips? Your feet are still cool in either case. Excess heat generation can occur if too much grease is used and churns in the housing. Most sealed bearings are 1/3 - 1/2 full of grease. High-speed machine tool spindles with grease lubricated bearings only have a 15% fill (that 15% of the available space inside the bearing) of grease, with almost all purged during break in (less than 5% effective.)

On the other side of the coin, if sufficient grease is not available we all know what will happen.

For our applications, the grease can only go two ways after purge, either outboard toward the cap/seal, or inboard toward the hub with the large void space.

Here's where temperature and housing design come into play. If the housing temperature is high, and the hub is spinning fast, and the void space is empty, the purged grease/oil may fling itself into the void space and not ever run back into the bearing.

For many of us packing the bearing full, filling the outboard cap, filling the void space between the cup/cone/washer, and filling the space between the seal and inner bearing cone will be sufficient. Enough additional oil will be released from this excess grease for most normal driving situations. I would however smear grease on the hub interior and hub shaft. This will help to reduce the chances of corrosion and the resultant rust particles from contaminating the bearings. It wont hurt anything to put a large dab in the hub void.

For those of us that push a bit harder, I'd recommend the same as above except to fill the hub void space a 1/3 full. This will allow for additional oil to be available to the bearings during high-heat conditions. I have been running this setup for four years using Pennzoil 707L Red Grease with good results.

Most late-model cars now use integrated hub units where the bearings are integral to the hub. These permanently sealed units are 1/3 - 1/2 full of grease.

[green69rt]

FSM says to fill hub even with bearing cones and hand (or pressure) pack bearings. As I did and show in my thread. I always did what you're saying ... until I read the FSM yesterday!   Mind you thinking back to the diagram showing a cutaway hub and what I think was their depicted grease fill I may have overdone it a bit!

EDIT: just did a little googling and I see all the arguing about it for both ways. This guy laid it out pretty good

First, what is grease, and why are its properties important for particular applications? Grease is roughly 90% oil, 5% thickener, and 5% additive packages (EP, R&O, etc). The thickener in grease acts the same as a sponge. Squeeze it, and the oil releases. This is the mechanical release of the lubricating oil from the thickener. Very little grease in or around the bearing is subjected to mechanical working. The other release method is temperature rise, of which all of the grease in most housings is subjected to. It is the release of the lubricating oil and how it travels in the housing that must be evaluated.

After the bearing is packed full, installed, and run a bit the bulk of the grease is channeled out of the bearing. In effect, the bearing will purge what it does not need. This is important since too much lubricant can cause overheating. Think of it like walking on the beach. Is it easier to walk in a thin film of water or water up to your hips? Your feet are still cool in either case. Excess heat generation can occur if too much grease is used and churns in the housing. Most sealed bearings are 1/3 - 1/2 full of grease. High-speed machine tool spindles with grease lubricated bearings only have a 15% fill (that 15% of the available space inside the bearing) of grease, with almost all purged during break in (less than 5% effective.)

On the other side of the coin, if sufficient grease is not available we all know what will happen.

For our applications, the grease can only go two ways after purge, either outboard toward the cap/seal, or inboard toward the hub with the large void space.

Here's where temperature and housing design come into play. If the housing temperature is high, and the hub is spinning fast, and the void space is empty, the purged grease/oil may fling itself into the void space and not ever run back into the bearing.

For many of us packing the bearing full, filling the outboard cap, filling the void space between the cup/cone/washer, and filling the space between the seal and inner bearing cone will be sufficient. Enough additional oil will be released from this excess grease for most normal driving situations. I would however smear grease on the hub interior and hub shaft. This will help to reduce the chances of corrosion and the resultant rust particles from contaminating the bearings. It wont hurt anything to put a large dab in the hub void.

For those of us that push a bit harder, I'd recommend the same as above except to fill the hub void space a 1/3 full. This will allow for additional oil to be available to the bearings during high-heat conditions. I have been running this setup for four years using Pennzoil 707L Red Grease with good results.

Most late-model cars now use integrated hub units where the bearings are integral to the hub. These permanently sealed units are 1/3 - 1/2 full of grease.

Actually, reading your thread is what prompted my question.   I was in a middle ground before.  I always put "some" grease in the hub, just not full.  Guess I'll keep doing what has worked for me for 50 years.

[birdsandbees]

I went out and pulled my hubs after I typed that and you know what, filled to the cups is only about 1/3rd full !

BTW... boat trailer hubs with bearing buddies are completely filled and under minor pressure. The pressure keeps any water from being able to flow in. They work just fine packed 100% full.