Rust-frozen brake bleeder screws
Since I grew up in the rust-belt, I’ve had problems in the past with frozen brake bleeder screws, my MH (which used to live in New York) is no exception. The brakes currently work well and have nice t...
Forum Discussion
Steve,
Being a lifelong coastal and rustbelt resident, I have developed a few (and just a very few) successful habits. Brakes and the bleed screws is one of those areas.
If you were also a resident of the metalworking groups on the web, you might have read a rather interesting study a couple of years back. One of the magazines wanted to do an scientific evaluation of the penetrating in lubricants that are available. They needed a control to compare all of these. So, someone knew of people that use a 50% mix of Acetone and ATF. They decided to use that as the control.
Problem....
In all and every test, the control was the most successful at reducing torque required to break away regardless of the fasteners age and condition. So, mix up some and put it in a pump oil can. Don't get a flame near it, but the ignition temperature is still pretty high and there should not be much there.
Before you get too far, assuming you get bleed screws open at all, drain the system. Use a small piece of clear tubing into a glass jar so you don't make a mess of things and can easily dispose of the scrap fluid. If you are going to pressure or vacuum bleed, you can use that equipment for this. If you are planning to gravity bleed, you can do that also, but it will not clear the system all that well. This will also make the next step much simpler and WAY cleaner.
When (If) you get your bleeders loose take each out and wire brush it clean. Then, either put a serious coat of teflon based pipe thread sealant on the thread or use two wraps (right hand) of teflon tape on the threads. (Now, someone is reading this and thinking "What kind of a bozo is this guy. Those thread don't seal anything! And, he is mistaken. Those thread have to A: seal the highly hydroscopic (soaks up water) brake fluid leaked at bleeding from helping the threads corrode again, and B: Keeping the outside water, salt or whatever from coming in from the top and corroding the threads - again.) There is the added benefit that if you are vacuum bleeding, you can get to clear fluid much sooner as no air will get sucked in the threads.
If you are planning to pedal-pump bleed a vehicle that old (well new from my point of view), resist the temptation. The extended stroke required will take the master cylinder seals places that they haven't been in years. This CAN (not will) damage those seals. If this can be avoided, you can put off replacing or rebuilding the master cylinder.
Lastly, but no less important, replace the little tiny rubber caps on the bleed screws. You never saw them? Well they were probably there once and then they either aged out and cracked and fell off, they got brake fluid on them and cracked and fell off or some ham-fisted mechanic didn't bother to put them back on.
Does all this stuff matter all that much? Well, it does to me, but then, I have a coach that is a little older than yours.
Matt
Being a lifelong coastal and rustbelt resident, I have developed a few (and just a very few) successful habits. Brakes and the bleed screws is one of those areas.
If you were also a resident of the metalworking groups on the web, you might have read a rather interesting study a couple of years back. One of the magazines wanted to do an scientific evaluation of the penetrating in lubricants that are available. They needed a control to compare all of these. So, someone knew of people that use a 50% mix of Acetone and ATF. They decided to use that as the control.
Problem....
In all and every test, the control was the most successful at reducing torque required to break away regardless of the fasteners age and condition. So, mix up some and put it in a pump oil can. Don't get a flame near it, but the ignition temperature is still pretty high and there should not be much there.
Before you get too far, assuming you get bleed screws open at all, drain the system. Use a small piece of clear tubing into a glass jar so you don't make a mess of things and can easily dispose of the scrap fluid. If you are going to pressure or vacuum bleed, you can use that equipment for this. If you are planning to gravity bleed, you can do that also, but it will not clear the system all that well. This will also make the next step much simpler and WAY cleaner.
When (If) you get your bleeders loose take each out and wire brush it clean. Then, either put a serious coat of teflon based pipe thread sealant on the thread or use two wraps (right hand) of teflon tape on the threads. (Now, someone is reading this and thinking "What kind of a bozo is this guy. Those thread don't seal anything! And, he is mistaken. Those thread have to A: seal the highly hydroscopic (soaks up water) brake fluid leaked at bleeding from helping the threads corrode again, and B: Keeping the outside water, salt or whatever from coming in from the top and corroding the threads - again.) There is the added benefit that if you are vacuum bleeding, you can get to clear fluid much sooner as no air will get sucked in the threads.
If you are planning to pedal-pump bleed a vehicle that old (well new from my point of view), resist the temptation. The extended stroke required will take the master cylinder seals places that they haven't been in years. This CAN (not will) damage those seals. If this can be avoided, you can put off replacing or rebuilding the master cylinder.
Lastly, but no less important, replace the little tiny rubber caps on the bleed screws. You never saw them? Well they were probably there once and then they either aged out and cracked and fell off, they got brake fluid on them and cracked and fell off or some ham-fisted mechanic didn't bother to put them back on.
Does all this stuff matter all that much? Well, it does to me, but then, I have a coach that is a little older than yours.
Matt
